COMMENTS ON AN ANNEX XV DOSSIER FOR IDENTIFCATION OF A SUBSTANCE AS SVHC AND RESPONSES TO THESE COMMENTS

Disclaimer: Comments provided during the consultation are made available as submitted by the commenting parties. It was the commenting parties own responsibility to ensure that their comments do not contain confidential information. The Response to Comments table has been prepared by the competent authority of the Member State preparing the proposal for identification of a substance of very high concern. RCOM has not been agreed by the Member State Committee nor has the document been modified as result of the MSC discussions.
		
Substance name: 1,4-dioxane
CAS number: 123-91-1
EC number: 204-661-8

The substance is proposed to be identified as meeting the following SVHC criteria set out in Article 57 of the REACH Regulation: Equivalent level of concern having probable serious effects on the environment (Article 57f), Equivalent level of concern having probable serious effects on human health (Article 57f)

PART I: Comments and responses to comments on the SVHC proposal and its justification

General comments on the SVHC proposal
Number / Date	Submitted by (name, submitter type, country)	Comment	Responses	
5481
2021/04/22	BASF SE, Company,
Germany		Thank you for your comment. 
Please see our responses for number “5481
2021/04/22” under the specific comments on the justification.

Regarding your comment on the consideration of phototransformation of 1,4-dioxane in surface water, we do not agree, that the results of the OECD 309 study have to be regarded as worst case scenario: The technical guidance document R.11 (ECHA, 2017) states, regarding the consideration of photochemical degradation processes in water: “Due to the large variation in the light available in different environmental compartments, the use of photolysis data is not generally recognised for persistence assessment.” However, for substances with a high residence time in water, contribution of photodegradation in water to overall degradation is significant. R.11 (ECHA, 2017)”.
The contribution of photolytic degradation in the water phase to the total degradation of 1,4-dioxane in this compartment is expected to be negligible. In addition, due to the lack of UV-adsorbing functional groups in the molecular structure, 1,4-dioxane is not expected to be directly photolyzed in water. Major releases of 1,4-dioxane will occur into surface waters that show only little potential for aquatic photolytic degradation due to depth of the water column, turbidity and presence of suspended matter that hamper the photolytic degradation potential. Therefore, despite the persistent properties and the resulting long residence of 1,4-dioxane in water, contribution of photodegradation in water to the degradation of the substance in the surface water simulations test is regarded to be low.
	
		Attachment: 5481_123-91-1_Final comment_BASF SE_20210422.pdf
		
5496
2021/04/22	BASF Intermediates,
Company,
Germany		Thank you for your comment. Your comment addresses the options to regulate 1,4-dioxane emissions, concluding that a restriction of specific uses would be sufficient. The German authorities conducted a comprehensive risk management option analysis (RMOA) to identify the most appropriate regulatory measure to control 1,4-dioxane emissions to the environment. In summary, the German authorities identified, that two measure are needed: 1. SVHC identification, 2. Restriction 
We kindly refer to RMOA conclusion document for further details: https://echa.europa.eu/documents/10162/010b37a1-9d0d-a69e-a703-df8626102fae	
		Attachment: 5496_2021 04 15 Comment to the identification of dioxane as SVHC vers 3.pdf
		
5510
2021/04/22	American Chemistry Council,
Industry or trade association,
United States of America	Please see attached comments	Thank you for your comments. 

Page 1-2 of the attachment:
1,4-dioxane is identified as an SVHC in accordance with Article 57 (f) of REACH. Such an identification is a case-specific assessment based on the specific hazard properties of each case. Specific criteria for mobility are not required for the assessment and the current guidance on Equivalent level of concern assessment and SVHC identification according to Art. 57(f) has been followed: https://echa.europa.eu/support/authorisation/substances-of-very-high-concern-identification.

The substance is completely miscible with water and has a low potential for adsorption on organic matter and clay minerals. These intrinsic substance properties lead to a high mobility in water. Section 6.3 of the Support document specifies the elements of concern used for the Equivalent level of concern assessment. It is the combinations of the intrinsic properties of 1,4-dioxane which leads to the SVHC identification. As explained below, safe concentrations limits for 1,4-dioxane in the environment cannot be derived.

Regarding your statement that SVHC identification is not necessary as there are enough other possibilities, the German authorities assessed regulatory measures to minimize emissions of 1,4-dioxane into the environment. Two measures are necessary to control environmental emissions of 1,4-dioxane. These are the identification as SVHC and a restriction of uses. We kindly refer to RMOA conclusion document for further details: https://echa.europa.eu/documents/10162/010b37a1-9d0d-a69e-a703-df8626102fae

Further, we disagree with your statement that safe concentrations limits for 1,4-dioxane in the environment can be derived from the available data. There are ecotoxicological tests available that show no effects or only at high concentrations. Those tests are mentioned in the dossier. However, in the support document it is explained that there is a concern for “as of yet unknown effects” on the environment that may not be observed in the standard toxicity tests or may only develop after life-long exposure. The support document continues to explain that this concern originates from the fact that 1,4-dioxane will remain in the environment for such a long time that effects on the environment that are not known today may be discovered in upcoming years.

Due to the persistency the substance will remain in the environment for a long time and due to its water solubility and low adsorption potential, 1,4-dioxane will remain in the water compartment and be fully bioavailable for uptake by wildlife or humans.

We revised section 6.3.2.6 of the support document accordingly. 

Regarding human health, carcinogenic substances should not be in drinking water as humans of each age (including vulnerable life stages) are exposed to it for their whole life. 

Regarding your comment on biodegradation of the substance we kindly refer to the revised section 3.1.2. of the support document. Thank you for your submission of additional references. Most of the references were considered in the weight-of-evidence approach (3.1.2.2.). However, we did not include all references, as some did not provide an added value to the dossier, as explained below:

18 ITRC. Technical resources for addressing environmental releases of 1,4-dioxane. Chapter 3, Environmental fate, transport and investigative strategies (2020). https://14d-1.itrcweb.org/

Reason not included: Evidence of metabolic and cometabolic biodegradation of 1,4-dioxane is already discussed in the support document. These resources do not bring any new information relevant to the SVHC identification. 

19 McElroy A and Hyman M. Biodegradation of ether pollutants. In Consequences of Microbial Interactions with Hydrocarbons Oils, and Lipids: Biodegradation and Bioremediation. R. Steffan (ed). Springer (2019). https://doi.org/10.1007/978-3-319-44535-9

Reason not included: The fact that some microorganisms are capable of metabolic 1,4-dioxane biodegradation is already discussed in the support document. This review does not bring any new information relevant to the SVHC identification.

23 Chiang S‐Y et al. Practical perspectives of 1, 4‐dioxane investigation and remediation.” Remediation Journal 27(1):7–27 (2016). https://doi.org/10.1002/rem.21494

Reason not included: The fact that some microorganisms are capable of metabolic 1,4-dioxane biodegradation is already discussed in the support document. This review does not bring any new information relevant to the SVHC identification. (Several of the references cited in the review are included in the Support document: Mahendra & Alvarez-Cohen, 2005; Parales et al., 1994; Shen et al.,2008) 

25 Adamson DT et al. Final Report: In situ treatment and management strategies for 1,4-dioxane contaminated groundwater. SERDP Project ER-2307. Strategic Environmental Research and Development Program. Alexandria, VA. (2017). https://serdp-estcp.org/index.php/Program-Areas/Environmental-Restoration/Contaminated-Groundwater/Emerging-Issues/ER-2307/ER-2307/(language)/eng-US

Reason not included: The findings of the project described on this website are published in these references already included in the support document:

Adamson D.T., Anderson R.H., Mahendra S., and Newell C.J. (2015): Evidence of 1,4-Dioxane Attenuation at Groundwater Sites Contaminated with Chlorinated Solvents and 1,4-Dioxane. Environmental Science & Technology 49 (11), 6510-6518

Adamson D.T., Mahendra S., Walker K.L., Rauch S.R., Sengupta S., and Newell C.J. (2014): A Multisite Survey To Identify the Scale of the 1,4-Dioxane Problem at Contaminated Groundwater Sites. Environmental Science & Technology Letters 1 (5), 254-258. DOI: 10.1021/ez500092u

27 Lee C-S et al. Removal of 1.4-dioxane during onsite wastewater treatment using nitrogen removing biofilters. Science Total Env 771:144806 (2021). https://doi.org/10.1016/j.scitotenv.2020.144806

Reason not included: The process applied in this study is nitrogen removing biofilters (layers of sand and woodchips) to treat effluent from septic tanks. We consider this process as not applicable for drinking water purification. Therefore, it was not included in our assessment.

Regarding your comment that 1,4-dioxane is not able to bioaccumulate and has limited potential for widespread environmental distribution: 

Monitoring results show that the substance has sufficient potential for widespread environmental distribution to compromise the integrity of drinking water resources.

As 1,4-dioxane cannot be removed using normal water treatment with activated carbon in drinking water treatment plants it is necessary to prevent the substance from reaching raw water.	
		Attachment: 5510_ACC comment on SVHC proposal for 1,4-dioxane - April 22.pdf

Page 1-2 of the attachment: “..there is no established definition, nor a scientific consensus, on the criteria to apply to a substance’s mobility and the conditions in which this characteristic would give rise to an equivalent level of concern (ELoC) to substances that meet the criteria of Article 57(a) to (e) of REACH. In particular, mobility is not a concept that is used under REACH to establish serious effects to human health or the environment, nor does it exist under the Classification, Labeling and Packaging (CLP) regulation. Also, there is no definition or criteria to assess mobility under REACH, nor outside of REACH, in a way that would be considered to result from a scientific consensus.

The concept of mobility is currently assessed as part of the exposure assessment required under REACH. Moreover, the environmental risk assessment aims to evaluate the exposure from the uses registered by the applicant, which includes consideration of release rates and environmental transport in the environment. As such, the mobility of a substance is already incorporated in the exposure assessment, since properties such as environmental fate and partitioning to and between different media are key input parameters.”		
5548
2021/04/23	Cefic,
Industry or trade association,
Belgium		Thank you for your comments. 

You commented that a screening assessment for the potential for long-range transport is not sufficient to support a complete evaluation of a substance’s property for long-range transport. We consider the LRTP assessment to be information which emphasises the potential for being transported in the water phase over long distances.

You commented that the assessment of mobility of the substance is supported by comparing the information to UBA’s assessment scheme for the so-called PMT and vPvM substances and note that these are not official criteria under REACH Annex XV. Moreover, this parameter is already included in the risk assessment framework under REACH which integrates mobility in the assessments of environmental exposure and men via environment. In response, we refer you to our reply to comment 5510 2021/04/22 above (page 1-2 of the attached comments from the American Chemistry Council).

You commented that for the dossier it is unclear how to distinguish between environment and human health concerns. In our view, the case of 1,4-dioxane is an ideal case to demonstrate the interconnection, how human health benefits from a protected environment. The environment harbours the most important drinking water sources. Any violation of the integrity of the environment may cause adverse effects even to humans. In the specific case of 1,4-dioxane, classified as a carcinogen (Carc. 1B) according to CLP, this means: Avoiding 1,4-dioxane contamination of drinking water sources prevents unwanted human health effects. 

Section 1 – Environmental concerns
Thank you for your comment on section 6.3.4 (the concern of yet unknown effects). We would like to note, that in the support document it is explained that there is a concern for “as of yet unknown effects” on the environment that may not be observed in the standard toxicity tests or may only develop after life-long exposure. The support document continues to explain that this concern originates from the fact that 1,4-dioxane will remain in the environment for such a long time that effects on the environment that are not known today may be discovered in upcoming years.

Due to the persistency the substance will remain in the environment for a long time and due its water solubility and low adsorption potential, 1,4-dioxane will remain in the water compartment and be fully bioavailable for uptake by wildlife or humans.
To strengthen this argumentation, we revised section 6.3.2.6 and 6.3.4 of the support document accordingly. 

Contrary to the view expressed by CEFIC, it is the consistent case-law of the EU Courts that the identification of SVHC on the basis of Article 57(f) of REACH does not necessarily need to take into account information other than information on hazards arising from the intrinsic properties of a substance. In other words, it is a possibility, but not an obligation.
 
For instance, in Case T-636/17 the General Court  held in paragraph 121: 
 “Generally, by providing that substances can be identified, on a case-by-case basis, if their serious effects on human health give rise to ‘an equivalent level of concern’ to that for those substances meeting the criteria for classification in the hazard classes carcinogenicity, mutagenicity or reproductive toxicity, Article 57(f) of Regulation No 1907/2006 does not prohibit the taking into consideration of data other than those relating to the hazards arising from the intrinsic properties of the substances concerned […] The latter ‘may include’, inter alia, the difficulty of adequately assessing the risks posed by those substances when it is impossible to determine, with the necessary certainty, a ‘derived no-effect level’ or a ‘predicted no-effect concentration’ (judgment of 15 March 2017, Hitachi Chemical Europe and Polynt v ECHA, C 324/15 P, EU:C:2017:208, paragraph 39). It follows that the migration limit of bisphenol A in certain objects, such as items intended to be in contact with food or toys, is a factor which ECHA can take into account for the purposes of identifying substances of very high concern, without that factor being decisive in that respect, and without it therefore being possible to conclude that the decision referring to such an identification is vitiated by a manifest error of assessment merely on account of a failure to take the permitted migration limit into account.”(underlining added)

Section 2 - Human health (man via environment) concern
CEFIC argues in the scope of exposure of humans via drinking water, that the risk was not assessed. We refer to above statement that the identification of SVHC on the basis of Article 57(f) of REACH does not necessarily need to take into account information other than information on hazards arising from the intrinsic properties of a substance.

Section 3 - Unclear assumptions
CEFIC sees a contradiction in the statement that environmental levels might increase if no action is taken in respect to monitoring observations from rivers. In section 3.2.4 the dossier submitter reported observations, e.g. at River Rhine, that levels of 1,4-dioxane are of constant levels. Considering that rivers are systems, in which new, fresh water is constantly getting contaminated with constant levels of 1,4-dioxane, it demonstrates in a first instance that there are constant releases to the environment. Taking into account the persistency of the substance, it is reasonable that 1,4-dioxane levels will increase in systems with less water exchange than river systems have. 

Furthermore, CEFIC argues that: “This data [no increase in environmental concentrations] is further supported by the information provided by the WHO in their analysis of 1,4-dioxane in drinking water which shows no increase in the levels measured in Japan over a 7-year span” . The Background document for development of WHO Guidelines for Drinking-water Quality (2005) reports environmental levels of 1,4-dioxane from nationwide surveys in surface waters in Japan from 1990 to 1997. Reported 1,4-dioxane levels in surface water ranged from n.d. to 35 µg/litre in 1990, from n.d. to 8.8 µg/litre in 1991, from n.d. to 19 µg/litre in 1992, from n.d. to 13 µg/litre in 1993, from n.d. to 15 µg/litre in 1994, from n.d. to 7.6 µg/litre in 1995, from n.d. to 9.02 µg/litre in 1996 and from n.d. to 42.8 µg/litre in 1997. No clear trend can be derived on concentrations/levels of 1,4-dioxane in Japans surface waters between 1990 and 1997. 
The WHO background document reports a second nationwide survey in Japan including surface water samples, coastal seawater samples and groundwater samples from 1995 – 1996; a study on raw water (no sampling date, Reference (Magara et al., 1998) and a study on tap water from six cities in Kanagawa, Japan, in 1995–1996. The latter one (Abe, 1997)  is already cited in the dossier whereas recent data for surface and groundwater in Europe provided sufficient evidence for contamination in these compartments. In the opinion of the evaluating MS, the report cited by CEFIC lacks the substantial basis to justify the assessment “supported by the information provided by the WHO in their analysis of 1,4-dioxane in drinking water which shows no increase in the levels measured in Japan over a 7-year span”.
CEFIC criticised in the context of “Decontamination can only be achieved at high societal costs, if at all.” “the phrase “If at all” is an overstatement as cases are known and described in the support document in which clean-up methods have been successfully applied to remove 1,4-dioxane from the water phase. There is no doubt, that methods are available which have the capacity to remove 1,4-dioxane from water. There is agreement on the fact, that those methods and techniques (e.g. reverse osmosis, or specific filters see section 6.3.2.2. of the support document) are not commonly used and highly energy demanding. It is questionable, whether all water suppliers or others affected by 1,4-dioxane contamination in Europe have the capacity to provide the necessary financial resources for these advanced water treatment techniques. We kindly ask to interpret the phrase “if at all” in this context. CEFIC referred to a case study from Bavaria (https://enveurope.springeropen.com/articles/10.1186/s12302-019-0286-x#Sec8). This study focusses on decontamination of waste water at the emission site. The process applied in this study is a catalytic oxidation with Fenton’s reagent and UV irradiation. We consider this process as not applicable for drinking water purification. Therefore, it was not included in our assessment. 

Section 4 of the CEFIC comment claims a lack transparency and predictability of the process. We are not sure whether the statement refers to REACH in general, or here specifically to 1,4-dioxane. 
In case of 1,4-dioxane, to identify the most appropriate risk management measure to minimize emissions of 1,4-dioxane into the environment, a risk management option analysis (RMOA) was conducted by the eMS in 2020. This RMOA considers the results of a consultation with stakeholders in December 2019 and revealed that measures to control environmental emissions of 1,4-dioxane are necessary. These are, in a first step,) the identification as SVHC and subsequently a restriction of uses. We kindly refer to the publicly available RMOA conclusion document for further details, why those two measures are needed: https://echa.europa.eu/documents/10162/010b37a1-9d0d-a69e-a703-df8626102fae

In section 5 of CEFIC’s comment it is stated that an identification of 1,4-dioxane based on CMR would trigger “communications requirements to consumers and for industry supply chains […] and promote substitutions”. However, Candidate Listing will also lead to a formal recognition of the SVHC properties. The hazard assessment during SVHC identification may therefore support potential subsequent risk management options. It would require the Registrants to acknowledge the SVHC status of 1,4-dioxane and to minimize emissions of this substance to the environment by the help of substance tailored operational conditions and risk management measures. “
Further, in section 5 you ask for the link between the environmental concern and the human health concern triggered by a CLH classification as Carc. 1B. We kindly refer to our initial statement on how human health can benefit from an intact, non-polluted environment.

Finally, you comment that a policy paper outlining a framework and key elements to support an identification as SVHC based on environmental ELoC needs to be developed and discussed with stakeholders. We have followed the current guidance on Equivalent level of concern assessment and SVHC identification according to Art. 57(f): https://echa.europa.eu/support/authorisation/substances-of-very-high-concern-identification. 

We stress that the fact that several substances are agreed and put onto the Candidate list based on a concern for Endocrine Disrupting effects on the environment suggests that the guidance for ELoC assessment is defined enough to deal with environmental concerns. ELoC considerations used in these cases typically relate to (but are not restricted to) severity and irreversibility of effect, broad environmental relevance and difficulty to set safe exposure levels. Similar arguments are brought up in section 6 of the Support Document.	
		Attachment: 5548_2021 04_Cefic comment on ELoC SVHC identification.pdf

Specific comments on the justification
Number / Date	Submitted by (name, submitter type, country)	Comment	Responses	
5458
2021/04/13	Health and Environment Alliance (HEAL),
International NGO,
Belgium	The Health and Environment Alliance (HEAL) thanks Germany for its proposal to identify 1,4-dioxane as SVHC under article 57(f) and we fully support this proposal.

Considering that the substance has previously been classified as carcinogen 1B (H350) by ECHA’s Risk Assessment Committee under the CLP regulation (regulation 1272/2008) and added in the 17th ATP, we consider the proposed SVHC identification on the human health part to be unequivocal.	Thank you for your support.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to occupational safety and health (OSH) and consumer safety, 1,4-dioxane is already sufficiently regulated in our view.  	
				
5468
2021/04/19	CHEM Trust Europe,
National NGO,
Germany	CHEM Trust supports the inclusion of 1,4-dioxane in the REACH candidate list based on article 57f. The Annex XV dossier provides a very convincing summary of the evidence regarding the problematic combination of the substance properties with the potential for serious and irreversible effects. These include a very high persistence, high mobility in water and potential for long range transport in water as predicted by the OECD tool for Long Range Transport Potential. The document contains a clear conclusion on the hazard properties and ELoC assessment for justifying the inclusion based on REACH article 57f. 

In addition to the inclusion in accordance with article 57f we also suggest inclusion based on article 57 a given the classification of 1,4- dioxane as a carcinogen 1B.

	Thank you for your support.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to OSH and consumer safety, 1,4-dioxane is already sufficiently regulated in our view.  	
				
5481
2021/04/22	BASF SE, 
Company,
Germany	BASF SE critically reviewed the environmental fate and ecotoxicological data with an emphasis on the long-range transport potential as given In the Annex XV report submitted by Germany (2021). The detailed review is part of the attachment to this summary.

The long-range transport potential (LRTP) was modelled using the OECD LRTP tool v2.2. The selection of the entered values for the parameters has a strong impact on the outcome of the assessment; therefore, the data have been reviewed critically.
The Henry’s Law Constant (HLC) was derived by Germany using the VP/WS method, which is inappropriate as 1,4-dioxane is completely miscible with water. Vapor pressure (VP) and water solubility (WS) were temperature-corrected using a method which was withdrawn by ECHA from its Guidance document R.7a in 2012. Using valid HLC data for the derivation of the air-water partition coefficient (log Kaw), reduced the overall persistence (Pov) from 1773 days to less than half (821 days and 698 days). Although these values are still above the boundary of 195 days as stated in the OECD LRTP tool for POP-like substances, the persistence is by far less as proposed in the Annex XV report. In addition, the strong influence of the parameters in the modelling of the LRTP is clearly demonstrated.
In the Annex XV report, the substance’s half-life was assessed based on a study which only considers biotic processes. However, in the environment 1,4-dioxane may also be degraded by processes like indirect phototransformation in air and water. By applying different half-life values in water which also consider abiotic processes, it could be demonstrated that small changes of the half-life of 1,4-dioxane can lead to a lower overall persistence – even below the boundary of 195 days.
With regard to the characteristic travel distance (CTD) and the transfer efficiency (TE), the estimated values from the model are clearly below the boundaries for POP-like substances in all scenarios. It can be concluded that the substance does not meet the boundary values for CTD and TE. 1,4-Dioxane is persistent in the environment due to its poor biodegradability; however, by applying rather small changes of the parameters considered in the LRTP modelling, the overall persistence can be reduced significantly.
Therefore, the results of the OECD LRTP tool v2.2 are ambiguous and do not prove that 1,4-dioxane meets the requirements for LRTP. Therefore, 1,4-dioxane should not be considered to have a potential for long-range transport.

Although it was shown in several short-term and long-term ecotoxicological studies for the three relevant trophic levels (fish, invertebrates, algae) that no environmental hazard was identified for 1,4-dioxane, the Annex XV report considered that the substance might cause potentially unknown long-term ecotoxic effects in combination with the classification of the 1,4-dioxane as Carc. 1B. However, any further request for testing is considered unjustified. The protection goal with regard to the environment are populations, not individuals as it is the case for human toxicology. There is no regulatory requirement and no method available to characterize the risk of carcinogenicity at the population level of environmental organisms. Therefore, the classification as Carc. 1B is not considered relevant with regard to long-term effects on the population of a species. Testing non-model species in non-standard test systems must be rejected as their acceptance especially in a regulatory context seems improbable.
In conclusion, 1,4-dioxane should not be considered as having long-range transport potential. With regard to the environment, no short-term and long-term hazard was identified.	Thank you for your comments.

We have checked your proposal and refined the HLC assessment. Due to that the substance is completely miscible with water we applied the value from the EPISuite data set because applying measured data is the preferred option in the assessments. This had an impact for the calculation of the CTD and overall half-life (POV), but not as much as in the calculation you provided with your comments. This is because:
- the average OH-Radical concentration in the atmosphere remained unchanged – 0.5x106/cm³ and a 24h-day is the default for exposure & fate predictions under REACH (please see guidance R.16)
- half-lives for water in the calculations remained unchanged as indirect photolysis is only relevant in shallow, clear waters (not to be found in surface waters receiving treated sewage water), and 
- the use of photolysis data is not generally recognised for persistence assessment (please see REACH Guidance R.11: PBT-Assessment).
In result, this made some impact for the calculation of the CTD and overall half-life (POV), but not as much as in your calculation with your specific assumptions. In final conclusion, the concern for LRTP was revisited based on the new results and the arguments were changed accordingly.

Despite the fact that ecotoxicological tests are available that show no effects or only at high concentrations 1,4-dioxane fulfils the T-criteria of REACH that is relevant for environment by fulfilling the condition for harmonised classification Carcinogen 1B. Hence long-term effects in the environment might appear or cannot be excluded. 
There is a concern for long-term effects in the environment, as 1,4-dioxane is very persistent and natural removal processes are lacking. Additionally the high mobility leads to a wide dissemination in the water body of the environment. Due to these properties of the substance the concern arises that yet unknown effects on the environment can appear that were not observed in the standard toxicity tests or may only develop after life-long exposure.
Several member states agreed that there is a concern for long-term effects in the environment. 

Response to page 3 of attachment: The study performed by Hofman-Caris & Claßen, 2020 is described in detail in Section 3.1.2.1.3 of the Support document. Sufficient details are provided to evaluate the study. Although the study was not performed according to GLP, it was conducted according to the OECD TG 309 and adequate and reliable documentation of the study is available. 

Page 7 of attachment, Log Kow: We have selected the Log Kow value of -0.27 because it was referenced by Hansch et al. (Hansch C, Leo A, Hoekman D. 1995. Exploring QSAR: Hydrophobic, electronic, and steric constants. Washington, DC: American Chemical Society. (referenced in ATSDR 2012)) Additionally, it was also agreed upon in a consultation process on the EU risk assessment report on member state level in 2002 (EU-RAR 2002).

Page 7 of attachment, Log Koc: The range of Koc values are discussed in Section 3.2.1 of the Annex XV dossier. We selected Log Koc of 0.85 because this value was already agreed upon in a consultation process on the EU risk assessment report on member state level in 2002 (EU-RAR 2002).	
		See the corresponding embedded attachment in table 1 of Part I: 5481_123-91-1_Final comment_BASF SE_20210422.pdf

Page 3 of attachment: “The available report from KWR (Hofman-Caris & Claßen, 2020) on the persistence of 1,4-dioxane in surface water derived a DT50 of > 10000 days for the degradation of the substance in the dark. The study cannot be fully evaluated, as the report is rather a summary with a general study description than a detailed study report which would be required for a GLP guideline study.”

Page 7 of attachment, Log Kow: "An octanol-water partition coefficient (log Kow) of -0.27 was selected according to Table 3 of the Annex XV report although this log Kow was estimated and no temperature was given. This value was taken from a secondary source ATSDR (2012) and originally published by Hansch et al. (1995). This value was also stated in the SRC PhysProp database with a reference temperature of 25 °C. BASF SE is not in accordance with the selected value. The current REACH dossier states a range of log Kow values between -0.27 and -0.42. In a weight-of-evidence approach, a log Kow of -0.42 (at 20 °C) was selected as the key value. However, changing the log Kow value from -0.27 to -0.42 did not change the outcome of the LRTP modelling.
Based on the low log Kow, 1,4-dioxane is not expected to adsorb to the solid soil phase. As the soil compartment is not relevant to the fate of 1,4-dioxane, the OECD LRTP tool does not consider the
entered DT50 for soil. Therefore, this value is not further discussed.”

Page 7 of attachment, Log Koc: “Although the adsorption coefficient (log Koc) is not considered in the OECD LRTP tool, it should be mentioned that the log Koc of 0.85 in the Annex XV report is outdated. The selected value has been taken from the EU RAR from 2002. There is no specific information on the estimation method used. In addition, no information is given on the applicability domain of the applied calculation method. The required QMRF and QPRF are not available/not provided. The current IUCLID dossier contains a log Koc that was calculated using a reliable and valid QSAR method (MCI method of KOCWIN v2.00, submodel of EPI Suite v4.11). The substance is within the applicability domain of the model. The robust study summary in the IUCLID dossier also contains the required QMRF and QPRF documents. The log Koc was calculated to be 0.42, indicating that the substance is not expected to adsorb to soil.”
		
5482
2021/04/22	ANSES,
National Authority,
France	ANSES supports the proposal of identification of 1,4-dioxane as SVHC according to 57f. ANSES considers that the concerns raised by 1,4-dioxane are mainly related to the following aspects:

The persistence/very persistence of 1,4-dioxane, lead to irreversible and increasing contamination of the environment in particular on the aquatic compartment.  The monitoring data reported on different locations on Europe and some places on United States, put in evidence that after release of the substance in the environment, this contaminated surface water reaches groundwater sources, even arriving to drinking water. These findings support the mobility capacity of the substance in the environment. The removal and decontamination of 1,4-dioxane from the environment and from drinking water is difficult, the available information shows that current conventional water purification techniques do not readily remove the substance; this explains the occurrence of the substance in drinking water in Europe. Humans are exposed directly and continuously during their whole life, which is critical because the substance is classified as carcinogenic 1B. We agree that further long-term effects can occur on humans and in the environment, even if the available aquatic studies do not show effects or only at high concentrations.
On this basis, ANSES agrees that 1,4-dioxane represents an equivalent level of concern justifying SVHC identification under article 57(f).

It is also noted that due to its harmonised classification Carc 1B, 1,4-dioxane fulfils the criteria for SVHC identification according to article 57(a) that can be proposed in addition.

More specific comments and suggestions are provided below

In relation to persistence (page 6 and 39) we suggest to reformulate the following phrase: “Degradation of 1,4-dioxane was investigated in surface water according to OECD 309 TG, resulting in a calculated DT50 (SFO) ≥10,000 days” as “Degradation of 1,4-dioxane was investigated in surface water according to OECD 309 TG, showing no degradation, the SFO model estimates a DT50 above 10,000 days”.

Page 39: The following paragraphs are quite redundant; you may synthetize in only one.

The substance is completely miscible with water (water solubility used for assessment = 1000 g/L) and has a log Koc of 0.85 indicating a low potential for adsorption on organic matter and clay minerals. These intrinsic substance properties lead to a high mobility in water. Additionally, the intrinsic substance properties indicate that the substance will partition primarily to the water compartment and will undergo environmental distribution via aqueous media, easily reaching groundwaters.

The high water solubility and low sorption potential of 1,4-dioxane make the substance difficult to remove from water as it only has a low potential to adsorb to materials and prefers to remain in the water phase.

Page 7: There is two paragraphs that are also quite redundant, you may synthetize as follow:

The very high persistency and its mobility result in an increasing pollution of the aquatic
environment. 1,4-Dioxane is difficult to remove once emitted to the aquatic environment. 1,4-Dioxane poses a threat to the resources of our drinking water, as due to its persistency and mobility, 1,4-dioxane can bypass river bank filtration and filtration with activated carbon, raising the concern of a continuous exposure of humans via drinking water. Any remediation efforts of contaminated drinking water resources will cause high costs to society. As the substance is very mobile causing a rapid distribution from the point source, remediation measures become even more difficult. Furthermore, 1,4-dioxane is carcinogenic and humans will be exposed via consumption and use
of drinking water. Consequently, there is societal concern for the presence of 1,4-dioxane in drinking water that requires immediate action.

Page 38 6.3.3. Equivalent level of concern assessment

It is not really clear the difference between both phrases: “Concern for an irreversible and increasing presence in the environment” and “Potential for irreversible and increasing contamination of surface water and groundwater”. The concern identified for the substance is mainly related to the aquatic compartment, especially on surface water and groundwater. We suggest merging both phrases.

Page 27 Data indicating potential for long range transport

As you indicate in the page 27, you run some estimations of the potential for long-range transport based essentially on estimated inputs parameters related to half-lives for biodegradation in surface water, bulk soil and sediment respectively. We agree with you that due to the intrinsic properties of the substance (high water solubility, the low volatility from water and the low potential for adsorption), water is the main transport media of the substance in the environment. However, we believe that caution is necessary for the interpretation and use of the results of the estimations.  We suggest nuancing the conclusion on potential long-range transport.	Thank you for your comment and detailed recommendations which we have considered in the revised support document. 

Please see below for specific responses.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to OSH and consumer safety, 1,4-dioxane is already sufficiently regulated in our view. 

Page 6: We changed the sentence as follows: “Degradation of 1,4-dioxane was investigated in surface water according to OECD TG 309, showing no degradation of the substance. Therefore, the degradation half-life of 1,4-dioxane is obviously higher than 60 days.”

Page 39: We changed the sentence as follows: “On the basis of a surface water simulation test (Hofman-Caris and Claßen, 2020) showing no degradation of the substance within 60 days, DT50 of 1,4-dioxane is regarded to be over 60 days. This result confirms that the substance qualifies as very persistent in water according to the persistency criteria of REACH Annex XIII.”

Thank for your remark on redundancy on page 39. We agree that the two paragraphs are redundant. However, the fact that the substance is highly water soluble and has a low adsorption potential is needed to explain two properties of the substance: its mobility in the environment (chapter 6.3.1.2) and its limited decontamination and removal capabilities from water (chapter 6.3.1.3).

Thank you for your comment on redundant paragraphs on page 7, which we considered in the revision of the support document.

Thank you for your remark on redundancy in chapter 6.3.3 which we considered in the revision of the support document.

Page 27, data for long range transport:
Thank you for your comment which we considered in the revision of the support document. In the consultation process there were comments in regard to the relevant LRTP model input parameter Henry’s Law Constant. In a chain of reasoning the LRT predictions were updated. In result, the CTD is still high, but now much more below the threshold for POPs. The corresponding conclusions were modified accordingly, arguing that the substance clearly does not meet POP long range transport criteria. However, data clearly shows that substance can be transported over large distances from point of initial release to the environment.

5489
2021/04/22	Norway,
Member State	We support the proposal to identify 1,4-dioxane as a Substance of Very High Concern according to REACH article 57. RAC opinion CLH-O-0000001412-86-264/F states that a classification as Carc. 1B; H350 is justified for 1,4-dioxane. Furthermore, the substance is very persistent, very mobile and contaminates the aqueous environment. These environmental properties imply a high potential for increasing pollution stock and for irreversible and increasing exposures of both wildlife and humans exposed via the environment. The low adsorption potential and high water solubility makes it very difficult to remove 1,4 dioxane by using end-of-pipe treatment and means that 1,4-dioxane is fully bioavailable for uptake via water. Together, these elements of concern lead to a very high potential for irreversible effects once effect levels have been reached, as well as an increasing seriousness of effects while exposures keep increasing. 

We therefore support that 1,4-dioxane should be identified as an SVHC according to both REACH article 57a (Carc. 1B) and 57f (Equivalent level of concern).

	Thank you for your support.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to OSH and consumer safety, 1,4-dioxane is already sufficiently regulated in our view.  

5496
2021/04/22	BASF Intermediates,
Company,
Germany	Page 6: proposal to Identify 1,4 dioxan as SVHC:

BASF SE would like to emphasize that the member state Germany concluded in the RMOA analysis from 2019 that a REACH restriction is the best regulatory instrument to address the environmental concern arising from 1,4-dioxane impurities. This opinion is also shared by BASF SE. However, the same member state is submitting a dossier for the identification of 1,4-dioxane as candidate for authorization, without considering that 1,4-dioxane should be finally regulated via a REACH restriction.

BASF SE is of the opinion that 1,4-dioxane should not be identified as a substance of very high concern because this would force ECHA to recommend the inclusion of 1,4-dioxane into Annex XIV to the EU Commission. According to Article 59 (1) of REACH regulation ECHA has the obligation to recommend every substance Identified as SVHC for Annex XIV inclusion to the EU Commission in the order of prioritization. BASF SE believes that a listing of 1,4 dioxane does not make sense and is contradictive regulatory action, since it would initiate the implementation of the different regulatory measures at the same time.

BASF SE is therefore of the opinion that a restriction under REACH should be initiated without listing the substance as an authorization candidate in parallel.

BASF SE is aware of substances that are now restricted instead of being regulated by REACH authorization regime. Nevertheless, this was a change of opinion (e.g. NMP; 872-50-4 and other aprotic solvents) on how to regulate the toxicological concern. Furthermore, those cases date back to times before the RMOA process was established to prevent such erroneous listings. For this reason, the NEP (Cas 2687-91-4) is correctly foreseen for Annex XVII inclusion without prior candidate listing
Finally, BASF SE believes that triggering a future authorization to address concerns arising from emissions coming from unavoidable impurities generated by specific production processes, is questionable at the very least.. Such situations are better addressed by specific EU legislations aimed at protecting water and air from such industrial emissions.
(see attachment for convenience = better reading)	

Please note that after successful SVHC identification the submission of a restriction proposal is foreseen by the DE CA. The respective dossier is already under preparation. Inclusion in the candidate list does not exclude the possibility for restriction later on in the process. Additionally, the conclusion document of the RMOA clearly stated our next steps (see: https://echa.europa.eu/documents/10162/010b37a1-9d0d-a69e-a703-df8626102fae). In that document, SVHC identification without subsequent authorisation but with subsequent restriction were presented as the next steps.

In this case, the SVHC identification of 1,4-dioxane is envisaged as the first step towards restriction. The restriction proposal is already under development. Nevertheless, it is true that the substance might still be prioritised for Annex XIV inclusion after the restriction process has been finalised. According to its current knowledge, the German CA is of the opinion that even after restriction the substance should not be made subject to authorisation.

Your opinion is noted.

	
		See the corresponding embedded attachment in table 1 of Part I: 5496_2021 04 15 Comment to the identification of dioxane as SVHC vers 3.pdf		
5497
2021/04/22	Sweden,
Member State	We thank Germany for this proposal. We support the proposal to identify the substance as SVHC meeting the criteria of Article 57 (f) due to its persistence, toxicity, and mobility. We agree, based on the provided data in the dossier, that 1,4-dioxane has properties for which there is scientific evidence of probable serious effects to human health and the environment which gives rise to an equivalent level of concern, according to the criteria of article 57(f) in REACH, to those of other substances listed in points (a) to (e) of Article 57 REACH.

We have following specific comments:
We agree to the arguments listed on page 8 for why 1,4-dioxane fulfils ELOC-criterion. However, we suggest that it is clarified that the unknown Long-term effects referred to considers the environment. The long-term effects for humans (cancer) are known.	Thank you for your support.

Thank you for you remark on specifying the ELoC on yet unknown effects (former phrased long term effects) to the environment, which we considered in the revision of the support document.

5502
2021/04/22	Netherlands,
Member State	The Netherlands CA supports the identification of 1,4-dioxane as SVHC under Article 57 (f) of REACH. The high persistency of 1,4-dioxane in combination with the high mobility of the substance in the aqueous phase, the indication for long-range transport, the substance its widespread occurrence at present, and the harmonized classification (cat. 1B) for carcinogenicity, leads to the conclusion that potential impacts to the environment and human health (men via environment) will proceed long after cessation of emissions, hence posing an irreversible threat to future generations and illustrating the urge to act now. The above elements lead to the conclusion that 1,4-dioxane is a clear example of a substance with PMT properties, and therefore should be identified as SVHC under ELoC accordingly.

As 1,4-dioxane has a harmonized classification (cat. 1B) for carcinogenicity, The Netherlands CA proposes to identify the substance as SVHC under Article 57 (a) of REACH as well and to include the necessary information.

	Thank you for your support.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to OSH and consumer safety, in our view, 1,4-dioxane is already sufficiently regulated.  

5510
2021/04/22	American Chemistry Council,
Industry or trade association,
United States of America	Please see attached comments	Thank you for your comment which we addressed in the comment section “General comments on the SVHC proposal”.	
		See the corresponding embedded attachment in table 1 of Part I: 5510_ACC comment on SVHC proposal for 1,4-dioxane - April 22.pdf		
5512
2021/04/23	Ireland,
Member State	We would like to thank Germany for preparing this proposal. Overall, we consider that there may be sufficient evidence to identify 1,4-dioxane as an SVHC in accordance with Article 57(f) due to scientific evidence of probable serious effects to the environment and human health (man via the environment) giving rise to an equivalent level of concern. We consider that the case could be strengthened by addressing the following points in the proposal:

• Section 6.3.2.5 describes the ‘Continuous presence in water results in continuous exposure of humans and environment’. The last two sentences in the final paragraph of that section states ‘Humans could be exposed to 1,4-dioxane over the whole life which is highly alarming as the substance is classified as carcinogenic. For these reasons and in application of the precautionary principle the release of 1,4-dioxane to the environment should be prevented’. In this context, we agree with the statement that humans could be exposed to 1,4-dioxane over their whole life and that this is of high concern (rather than “highly alarming”).   In addition, we consider that the reference to ‘application of the precautionary principle’ should be removed as 1,4-dioxane is classified as carcinogenic category 1B, which is a known health effect, providing  sufficient evidence to support the conclusion without the need to include a  reference to the precautionary principle.
Therefore, we propose the following rephrasing of last two sentences as follows: ‘Humans could be exposed to 1,4-dioxane over their whole life which is of high concern, as the substance is classified as a carcinogen category 1B. For these reasons, the release of 1,4-dioxane to the environment should be prevented’.

• Section 6.3.2.6 describes ‘Long term effects are unknown’. We agree that there is the potential for long-term effects, which are unknown. This is different to the statement ‘long-term effects are unknown’, as some of the long-term effects are known (e.g. carcinogenic effects). The newly updated SVHC Annex XV template references ‘Potential for causing serious effects on human health (known and unknown), and the environment (including the potential for irreversible effects)’. In this context, we consider that the title of this section could be amended to ‘The potential for long-term effects are unknown’ and the argument strengthened to reflect the potential for other unknown long-term effects (e.g. persistency).

• Section 6.3.4 describes the ‘Conclusion on hazard properties and ELoC assessment’. The twelfth paragraph states ‘Due to the properties of 1,4-dioxane (persistency, mobility, long-range transport and carcinogenicity) it is not possible to derive a safe concentration limit for the environment. Monitoring data demonstrate the presence of 1,4-dioxane in surface water, groundwater and even drinking water across the globe. Sources of emission in the vicinity are seldom apparent’.

We agree with the above statement and the concern identified, as a safe concentration of 1,4-dioxane cannot be derived. We note that reference to the inability to derive a safe concentration was briefly touched upon in section 6.3.2.6 (last sentence). In our view, we consider the inability to derive a safe concentration to be an important element of the ELoC argument and recommend including a stand-alone sub-section in section 6.3.2., which would link this concern to the ELoC argument.	Thank you for your comment and suggestions, which we considered in the revision of the support document.

We agree that the inability to derive a safe concentration for the environment is an important ELoC argument. Nonetheless, key elements of ELoC are the same as for ‘Yet unknown effects’. Therefore, we refined the title of chapter 6.3.2.6. and included this important ELoC element.	
				
5516
2021/04/23	European Environmental Bureau (EEB),
International NGO,
Belgium	The EEB supports the proposal by Germany to identify 1,4-Dioxane as SVHC due to its persistent, mobile and toxic properties leading to an equivalent level of concern in the environment to PBT and vPvB substances.

1,4-Dioxane should be identified as SVHC because of the combination of extreme persistency, high mobility and carcinogenicity. The substance is widely found in the environment, including surface water, ground water and drinking water. The environmental pollution is increasing and irreversible. 1,4-Dioxane is detected in drinking water in Germany, Spain and other countries across the globe and citizens will be exposed to this carcinogenic substance via the consumption of drinking water. Its persistency, mobility, widespread occurrence in the environment and presence in drinking water in combination with carcinogenicity gives rise to identification as SVHC according to article 57(f) of REACH. 

EEB welcomes the inclusion of 1,4-Dioxane in the REACH Candidate List and recommends prioritising the substance for further regulatory risk management. 

1,4-Dioxane should be identified additionally as SVHC according to REACH Article 57(a) due to the upcoming classification as Carc 1B as agreed in the RAC opinion of 2019.

	Thank you for your support.

Thank you very much for your support regarding the SVHC identification of 1,4-dioxane. Please note that as a next step a restriction proposal will be drafted and submitted. This is already under preparation.

We do not see the benefit of an additional SVHC identification of 1,4-dioxane according to Article 57 a), as the concern we have with the substance is mainly related to its presence in the environment. With regard to OSH and consumer safety, 1,4-dioxane is already sufficiently regulated in our view.  

5524
2021/04/23	ChemSec,
International NGO,
Sweden	ChemSec supports the identification of 1,4-dioxane as a Substance of Very High Concern. While the carcinogenic properties alone justifies Candidate Listing, the combined PMT properties makes it particularly concerning, highlighted by it being frequently detected in drinking waters. ChemSec added 1,4-dioxane to the SIN List as a PMT in 2019.	Thank you for your support.	
				
5540
2021/04/23	Finland,
Member State	We thank Germany for this proposal. We consider that 1,4-dioxane fulfils the conditions for SVHC identification as a substance of equivalent level of concern to those of other substances listed in points (a) to (e) of Article 57 of Regulation (EC) No 1907/2006 (REACH) according to Article 57(f) of REACH Regulation. We have the following comments regarding the Annex XV report:

	Thank you for your support. Specific comments are responded to below.

	
				
		page 6: “Degradation of 1,4-dioxane was investigated in surface water according to OECD 309 TG, resulting in a calculated DT50 (SFO) ≥10,000 days.”
comment: No degradation was observed in the study. Therefore, we do not think that it is meaningful to present an extrapolated half-life. We propose to indicate that no degradation was observed and therefore the half-life is higher than 60 days and that it may be significantly higher.
	Page 6: We changed the sentence as follows: “Degradation of 1,4-dioxane was investigated in surface water according to OECD TG 309, showing no degradation of the substance. Therefore, the degradation half-life of 1,4-dioxane is obviously higher than 60 days.”.
	
		page 7: “1,4-Dioxane was not removed from water.”
comment: We propose specifying this sentence, e.g., what type of water is meant (waste water, raw water for drinking water production), and what location/process? If the essential information is already included in the preceding sentence, this sentence could be deleted.
	We changed the sentence as follows: “The result indicates, that the substance will not be removed from water by this purification technique, which is generally applied across Europe.”	
		page 8: “Equivalent level of concern bullet points: “Long-term effects are unknown”
comment: Please consider to modify this to for example “Long term effects of the substance at low levels are possible but unknown”. Unknown effects alone are difficult to justify as an element of equivalent level of concern. Note that possible long-term effects are considered as supporting concern in the section above and this could also be highlighted in the bullet point. We think that possible long-term effects could be supporting concern due to all other concern elements already listed.	Thank you for your comment. We changed the title and enhanced the meaningfulness of the chapter.
	
		page 14: ”MITI non-linear model prediction results (Biowin6) indicates that 1,4-dioxane is readily biodegradable, because the probability is greater than or equal to 0.5 (estimated value = 0.5539).”
comment: We obtained a different probability value with Biowin 6 (0.6713). (Biowin v4.10 in Epi Suite v4.11)	QSAR model predictions were performed using BIOWIN v4.11. This seems to be the reason for deviation. However, the outcomes of the different model versions do not change the overall results for the BIOWIN 6 result (i.e. 1,4-dioxane is readily biodegradable), because both values are above 0.5.	
		page 15: “The inconsistent results from the BIOWIN QSAR predictions mentioned above could be attributed to the very small size of the molecule, which causes the (low) molecular weight parameter in the BIOWIN equation. This strongly influences the degradation prediction, because low molecular weight is considered to be easier biodegradable then high molecular weight. Furthermore, the contribution of the aliphatic ether fragment could be an explanation for the result “readily biodegradable” (Biowin6). In Biowin2 and 3 this fragment is rated negative (aliphatic ether is considered to make biodegradation slower), but in the Biowin6, this fragment has a positive contribution, meaning that the aliphatic ether is in this model considered to improve biodegradability. However, as explained above in general the aliphatic ether bonds are considered to be difficult to biodegrade in the literature, making the reliability of the Biowin6 prediction (readily biodegradable) questionable.”

comment: In Biowin 2, 3, and 6 the aliphatic ether fragment has a negative coefficient (-3.4294, -0.00867, -0.10714727). Therefore, the text should be corrected. Regarding the molecular weight, in general, the molecular weight parameter is relatively important in Biowin predictions. However, we are not convinced that molecular weight would explain the inconsistent results from the Biowin QSAR predictions. We consider that such a conclusion can only be drawn if the model training sets are analysed. The fragment coefficients in Biowin models are derived from biodegradability results for training set compounds containing the specific fragments. The training sets for Biowin 1-2, Biowin 2-3, and Biowin 5-6 contain 11, 16, and 32 compounds containing the aliphatic ether fragment, with maximum number of instances 2, 5, and 3, respectively. To estimate the contribution of the molecular weight to the predicted biodegradation of ether compounds, molecular weights of the training set compounds could be compared to the predicted and observed biodegradation results of the compounds (to see, for example, whether the degradability of low molecular weight ether compounds is consistently overestimated compared to the observed results). Also, if there are structurally similar substances to 1,4-dioxane in the training (or validation) sets, it could be considered whether the predictions for the compounds match the observed biodegradation results used for the model derivation. This type of analysis is not included in the document and therefore we propose modify the text to make it less conclusive regarding the reason for the inconsistent Biowin results. Another possible reason for the relatively high predicted biodegradability is that Biowin models 1-4 do not include the cyclic carbon fragment and in Biowin 5-6 the cyclic carbon has a positive coefficient. Even if the whole molecule is covered by the Biowin predictions, it should be noted that the fragment coefficient for aliphatic ether is derived from different types of compounds and they may not have the same structural features as 1,4-dioxane (for example, the cyclic structure with only single bonds between carbon atoms). In Biowin 1-4, the structure is recognized as two aliphatic ether fragments and therefore the prediction is highly dependent on that fragment. In Biowin 5-6, the structure is recognized as two aliphatic ether fragments and four -CH2- cyclic fragments, and the -CH2- cyclic fragment has a positive coefficient.	We changed the paragraph as follows: “The inconsistent results from the BIOWIN QSAR predictions mentioned above could be attributed to the different rating of the substance fragments within the models applied. In Biowin2 and Biowin3, the 1,4-dioxane structure is rated as two aliphatic ether fragments and therefore the prediction is highly dependent on that fragment. However, in Biowin6, the 1,4-dioxane structure is rated as two aliphatic ether fragments as well as four -CH2- cyclic fragments. In contrast to the aliphatic ether fragment, these -CH2- cyclic fragments have a positive coefficient improving the biodegradability of 1,4-dioxane in the Biowin6 model. However, as explained above in general the aliphatic ether bonds are considered to be difficult to biodegrade according to the literature, making the reliability of the Biowin6 prediction (readily biodegradable) questionable.”
	
		page 15:
comment: The types of inocula (e.g., activated sludge) for the screening tests could be added, where not already included. This is of interest for the later considerations regarding the potential of wastewater treatment plant microorganisms to degrade the substance.	We included the information on the inoculum source in the support document. 
	
		page 15: “Measurement of the oxygen demand suggests that decline in 1,4-dioxane concentration is based on elimination.”
comment: This could be clarified. Does it mean that the decrease was not due to degradation? Was there an increase in oxygen consumption?	We agree to further specify that the oxygen demand indicates that decrease in substance concentration was caused rather by elimination than by degradation. We changed the sentence to: “However, measurement of the oxygen demand suggests that decline in 1,4-dioxane concentration is based on elimination instead of degradation.”
	
		page 15: “No standard simulation tests with 1,4-dioxane or other cyclic ethers in water and sediments are available.”
comment: An OECD TG 309 study is available and described in the proposal. Therefore, please clarify or modify/delete the sentence accordingly.	We include the information that no simulation test in water and sediment is available on the ECHA dissemination site.
	
		page 15-16:
comment: Please consider whether the studies by Kim (2007) and Sei et al (2010) should be classified as a screening tests rather than simulation tests. The concentration 10 mg/L is typical to those used in ready biodegradability tests whereas the concentration of 100 mg/L is at the upper end of concentration range of ready biodegradability tests. Also, the durations of the tests are shorter than e.g. OECD TG 309.	We agree that the studies of Kim et al. (2007) and Sei et al. (2010) should be classified as a screening tests rather than simulation tests. We transfer the study results to section “3.1.2.1.2. Screening tests”.
	
		page 16:
comment: Regarding the study by Klečka and Gonsior (1986), some more details would be welcome. The concentration (100 mg/L) is in the range of some screening tests. Is it considered relevant in wastewater treatment systems?	After checking the literature again it became obvious that the control test vessel (for which no decline in test concentration were observed) consists of 465 mg/L of H2O2 solved in distilled water and 100 mg/l 1,4-dioxane. Because this test conditions are not transferable to environmental conditions, we delete the reference from Klečka and Gonsior (1986) from the dossier.	
		page 16: “The 1,4-dioxane concentration remained stable over the course of time and ranged between a minimum value of 71.1 ± 5.5 μg/L at day 15 and a maximum value of 93.3 ± 0.4 μg/L at day 30. At the end of the study (day 60), 85.8 ± 3.2 μg/L 1,4-dioxane could be detected in the surface water.”

comment: Based on these results it seems that there was no decrease in concentration during the study. Therefore, we consider that it is not possible to derive a reliable half-life from this study. The chi2 error percentage and visual fit indicate only whether or not the model-predicted concentrations reasonably match the measured concentrations but they do not indicate the reliability of the calculated half-life in this case, as no decrease was observed. We recommend adding a graphical presentation of the data (concentration vs. time) and adding the values of the rate constant (k) and the associated p-value. We consider that it should be stressed in the document that no degradation during the study was demonstrated and that therefore the half-life is considered to be over 60 days and the calculated half-lives are highly uncertain. It is possible that degradation would occur over longer exposure in the environment (or even in the same test bottles after 60 days, if detrimental “bottle effects” leading to decreased viability of inoculum are not occurring). We can support the conclusion on the P and vP properties of the substance based on the data presented but we consider that it from the present study it can be concluded only that the half-life in water is above 60 days and that it may be significantly longer than 60 days. In the MSC support document for 2-Benzotriazol-2-yl-4,6-di-tert-butylphenol (UV-320) (EC 222-346-6) it was stated: “Please note that not in all cases the DT50 was reached within the experimental period. Extrapolation of data is always insecure and thus respective DT50 should be interpreted with care. Nevertheless, it is possible to conclude on reaching certain trigger values although it is impossible to define exact values.”. We recommend to follow the same line of reasoning here.	We add a figure illustrating the concentration as a function of time (Figure 1). 

We agree that the calculated degradation half-life are highly uncertain as no decline in test concentration and thus degradation occur. We thus change the paragraph as follows: “Calculated half-lives (DT50) of 1,4-dioxane are shown in Table 6. However, as no degradation of the substance appears during the study, the calculated half-lives are considered uncertain. Extrapolation of data is insecure and thus respective DT50 should be interpreted with care. Nevertheless, it is possible to conclude on reaching certain trigger values, even though it is impossible to define exact values. Thus, DT50 of 1,4-dioxane is regarded to be over 60 days.”
	
		page 17:
comment:  Regarding the degradation studies in soil, some consideration could be given to the test conditions, such as test substance concentration, and their comparison to standard soil simulation tests. The test concentrations (e.g. 100 mg/kg) seem to be high compared to the OECD TG 309 study (less than 100 µg/L). For example, are the test concentrations so high that a significant decrease of the test substance would actually warrant growth of microorganisms with 1,4-dioxane as a sole carbon source (as in screening tests)? Also, in principle, an environmentally relevant decrease in concentration could even remain undetected if the test substance concentration is too high, as a change in concentration may be too low to be detected due to deviation from analytical method, sampling, or variation between replicates.	We agree that high concentrations used in the soil suspensions described in Sei et al. (2010) can challenge the detection of small changes in the concentration of the test item and outlined this in the corresponding studies.
	
		page 17: “In general, soil microbes at contaminated sites are considered to be incapable of degrading 1,4-dioxane under ambient conditions (Lesage et al., 1990).”.
comment: We are not convinced about the validity of this argument. It seems that microorganisms degrading 1,4-dioxane are relatively common and both growth-based and co-metabolic degradation is possible. Many studies on degradation of 1,4-dioxane have been conducted since the publication of the article by Lesage et al (1990).
He et al (2017) mention that although dioxane is relatively recalcitrant, a number of strains capable of degrading dioxane have been isolated. According to the authors, most of these strains degrade dioxane cometabolically [i.e. dioxane degradation is induced by another substrate, and it does not serve as carbon or energy source to support bacterial growth]. Nearly all of these strains were isolated from wastewater treatment plants or dioxane-impacted sites. Many of the strains originate from soil. He et al (2017) reported that two bacterial consortia were enriched from uncontaminated soil by virtue of their ability to grow on 1,4-dioxane (dioxane) as a sole carbon and energy source. They stated that after 12 cycles of enrichment for approximately 3 months, rapid dioxane biodegradation was sustained at relatively constant rates by both consortia. They concluded that dioxane-degrading bacteria (and the associated natural attenuation potential) exist even in some uncontaminated soils, and may be enriched to broaden bioaugmentation options for sites experiencing insufficient dioxane catabolic capacity.

Inoue et al (2016) studied 1,4-Dioxane degradation potential of bacterial pure cultures
The provided a table with information on 1,4-dioxade-degrading strains (Table S1 in Online Resource 1), several of which have been found from soils. Li et al (2017) studied 1,4-Dioxane biodegradation in microcosms prepared with groundwater
and soil from an impacted site in Alaska.

References:

Ya He, Jacques Mathieu, Marcio L.B. da Silva, Mengyan Li, Pedro J.J. Alvarez. 1,4‐Dioxane‐degrading consortia can be enriched from uncontaminated soils: prevalence of Mycobacterium and soluble di‐iron monooxygenase genes, Microbial Biotechnology (2018) 11( 1), 189– 198. https://doi.org/10.1111/1751-7915.12850

Inoue, D., Tsunoda, T., Sawada, K. et al. 1,4-Dioxane degradation potential of members of the genera Pseudonocardia and Rhodococcus . Biodegradation 27, 277–286 (2016). https://doi.org/10.1007/s10532-016-9772-7

Mengyan Li, Yuanyuan Liu, Ya He, Jacques Mathieu, James Hatton, William DiGuiseppi, Pedro J.J. Alvarez, Hindrance of 1,4-dioxane biodegradation in microcosms biostimulated with inducing or non-inducing auxiliary substrates, Water Research, Volume 112, 2017, Pages 217-225, ISSN 0043-1354, https://doi.org/10.1016/j.watres.2017.01.047.	We agree that more recent studies on biodegradation of 1,4-dioxane than from Lesage et al. (1990) are available and changed the paragraph as follows: “He et al. (2018) reported that although 1,4-dioxane is relatively recalcitrant, a number of strains capable of degrading 1,4-dioxane have been isolated. According to the authors, most of these strains degrade dioxane cometabolically, meaning that 1,4-dioxane degradation is induced by another substrate, and it does not serve as carbon or energy source to support bacterial growth. Nearly all of these strains were isolated from wastewater treatment plants or dioxane-impacted sites. Many of the strains originate from soil.”

According to the comments by the American Chemical Council, we included some new references describing the degradation of 1,4-dioxane using isolated microorganisms strains with different origin (Mahendra, 2005, 2007; Barajas-Rodriguez, 2018; Ramalingam, 2020; Shen, 2008; Chen, 2016; Huang, 2014; Hatzinger, 2017). To get a better overview, we cluster the references regarding whether the 1,4-dioxane degradation was studied under aerobic or anaerobic conditions. Furthermore, we added which microorganisms isolated from uncontaminated soil were responsible for degradation and how degradation was monitored.

We agree that some of the study’s results deliver clear indications for the degradation/cometabolic degradation of 1,4-dioxane by isolated microorganism strains. Thus, we changed the outcome for these studies as follows: “However, as isolated microorganism strains were used, the studies are only applicable to show that 1,4-dioxane is biodegradable under specific conditions.”

		page 17: “Some non-standard studies with isolated soil bacteria in pure or mixed culture from different locations indicate some potential for biodegradation of 1,4-dioxane (Bernhardt and Diekmann, 1991; Burback and Perry, 1993; Inoue et al., 2016; Parales et al., 1994; Pugazhendi et al., 2015; Sales et al., 2013; Sei et al., 2013; Sock, 1993). However, not all of these studies investigated the identity of the degradation products – only the disappearance of the parent compound was analysed. Therefore, it is not clear whether the decrease in 1,4-dioxane concentration was caused by dissipation or degradation of the parent compound."

comment: Appearance of metabolites and increase in biomass and CO2 should be considered as indicators of degradation, provided that they are clearly demonstrated to originate from 1,4-dioxane. From the current wording it is unclear whether all of these have been considered in interpretation of the studies. At least in the study by Parales et al, CO2 and optical density were measured. When 1,4-dioxane is used as a sole carbon source, and assuming that autotrophic growth is negligible, increase in optical density and CO2 indicates that degradation of 1,4-dioxane occurred. Parales et al state that  “Although a complete mass balance has not been determined, we have demonstrated that more than 50% of the carbon from 1,4-dioxane is converted to CO2 by CB1190 and no organic products other than biomass accumulated in the growth medium, indicating that 1,4-dioxane is mineralized by CB1190. Since no intermediates of 1,4-dioxane degradation could be detected in spent medium, we have no information from which to construct a pathway for 1,4-dioxane degradation.” Therefore, we propose to modify this paragraph, at least the last sentence, to be more consistent with the referred studies.	We agree that in most of the studies degradation was monitored by CO2, analysis of the test substance concentration and transformation products. We thus delete the following sentence: “However, not all of these studies investigated the identity of the degradation products – only the disappearance of the parent compound was analyzed. Therefore, it is not clear whether the decrease in 1,4-dioxane concentration was caused by dissipation or degradation of the parent compound."	
		page 17: “In a study using soil microcosms (Kelley et al., 2001), 1,4-dioxane was not degraded during a period of 120 days. The microcosms contained 20 g of soil dissolved in 200 mL basal salt media and 25 mg/L 1,4-dioxane was added. Degradation was monitored using GC-FID analysis.”
comment: This was a soil suspension test with a concentration typical to screening tests. Some details could be included, e.g. was the viability of the inoculum checked and were the microcosms maintained aerobic.	We changed the study description for Kelley et al. (2001) from “soil microcosm” to “soil suspension”. The vessels were periodically aerated with sterile air. However, the activity and viability of the inoculum wasn’t checked.	
		page 17: “In conclusion, based on the weight of evidence, 1,4-dioxane is evaluated as not capable to undergo noticeable biodegradation in soil under environmentally relevant conditions.”

comment: We have some reservations whether this can be concluded based on the studies introduced in this section only, considering that there are no standard simulation tests in soil available and as there are deficiencies and open questions in the available soil biodegradation studies. In addition, CO2 production was observed in one of the studies (Kelley et al 2001). We propose to conclude in this section only that in most of the studies with non-contaminated soil, degradation was not observed.	We changed the conclusion on degradation in soil as follows: “In conclusion, based on the weight of evidence, 1,4-dioxane does not degrade in the absence of known 1,4-dioxane degrading soil microorganism strains.”
	
		page 18: “Based on the lack of any primary degradation in water as shown in the screening tests available and other studies on biodegradation and the very high DT50 value of 1,4-dioxane in surface water, it is concluded that the biodegradation of 1,4-dioxane in the aquatic environment is very slow or negligible.”
comment: We note that primary degradation was apparently not measured in the reported screening tests, with the exception of Sei et al (2010), as regarding the other tests there is no mention of primary degradation measurement in the document. In line with our preceding comments on the OECD TG 309 study, we propose to modify, e.g. to “Based on the low degradation in water as shown in the screening tests available and other studies on biodegradation, including the surface water simulation test, it is concluded that the biodegradation of 1,4-dioxane in the aquatic environment is very slow or negligible.”	We changed the conclusion as follows: “Based on the low degradation in water as shown in the screening tests available and other studies on biodegradation, including the surface water simulation test, it is concluded that the biodegradation of 1,4-dioxane in the aquatic environment is very slow or negligible.”
	
		page 18: 3.1.3 Field data
comment: We propose to consider including the following articles:
David T. Adamson, R. Hunter Anderson, Shaily Mahendra, and Charles J. Newell. Evidence of 1,4-Dioxane Attenuation at Groundwater Sites Contaminated with Chlorinated Solvents and 1,4-Dioxane. Environmental Science & Technology 2015 49 (11), 6510-6518. https://pubs.acs.org/doi/abs/10.1021/acs.est.5b00964)
Gedalanga, P., Madison, A., Miao, Y.(., Richards, T., Hatton, J., DiGuiseppi, W.H., Wilson, J. and Mahendra, S. (2016), A Multiple Lines of Evidence Framework to Evaluate Intrinsic Biodegradation of 1,4‐Dioxane. Remediation, 27: 93-114. https://doi.org/10.1002/rem.21499

Adamson et al (2015) presented, for instance, attenuation rates and half-lives for 1,4-dioxane at contaminated groundwater sites. Gedalanga et al (2016) used a multiple lines of evidence framework to evaluate valuate the intrinsic biodegradation potential of 1,4‐dioxane in groundwater sites.	Thank you for mentioning the articles. We included them in the dossier accordingly.	
		page 18: “On the basis of the observed lack of any primary degradation in water (Kim, 2007; Klečka and Gonsior, 1986; Sei et al., 2010) and soil (Kelley et al., 2001; Sei et al., 2010), there is already very strong evidence, that the substance might be rated to be persistent or even very persistent in water and soil.”
comment: Based on the information in the proposal and the deficiencies and open questions regarding the referred studies we do not agree that the studies referred in this sentence provide a very strong evidence for P or vP in water and soil. We consider that these studies suggest that the substance is potentially P/vP. In addition, as there is also a standard simulation test available, the paragraph could perhaps be reformulated so that all the water studies are considered together and that they indicate P/vP in water. It is not necessary to first formulate a hypothesis based on the less relevant studies only.	We agree to use the studies of Kim et al. (2007) and Sei et al. (2010) to support the evaluation of the substance as potentially p/vP. We thus change the paragraph as follows: “In screening tests regarding ready degradability negligible mineralisation occurred, even after an extended study period or utilisation of adapted inoculum. In other studies on degradation of 1,4-dioxane in water (Kim et al., 2007; Sei et al., 2010) no degradation of 1,4-dioxane was detected. This data demonstrates that the substance is potentially persistent / potentially very persistent in water according to the screening criteria of REACH Annex XIII.”
	
		page 18: “This hypothesis was confirmed by the very high DT50 (SFO) ≥10,000 days of
1,4-dioxane in a surface water simulation test with surface water (Hofman-Caris and Claßen,
2020).”
comment: In line with our preceding comments on the OECD TG 309 study, we propose deleting the unnecessary reference to the hypothetical SFO half-life and, instead of that, referring to the lack of degradation during the study.	We agree to delete the highly uncertain estimated DT50 and refer to the lack of biodegradation of the substance in surface water. We change the paragraph as follows: “On the basis of a surface water simulation test with surface water (Hofman-Caris and Claßen, 2020) showing no degradation of the substance within 60 days, DT50 of 1,4-dioxane is regarded to be over 60 days. This result confirms that the substance qualifies as very persistent in water according to the persistency criteria of REACH Annex XIII.”	
		page 19: “Considering the data on abiotic and biotic degradation, it is concluded that 1,4-dioxane is persistent and very persistent in the aquatic compartment and in soil”
comment: The situations with the data sets for water and soil are different, as a standard simulation test is available only for water. We propose to consider whether it is appropriate to definitively conclude on the P/vP in soil or whether the justifications to this be improved. Although according to ECHA guidance R.11., results of a single simulation degradation study cannot be directly extrapolated to other environmental compartments, the guidance states that results could be sufficient to conclude on persistence in other compartments, provided that the environmental media in environmentally realistic conditions have been selected for the study and the interpretation of the results/bridging is backed by proper justifications.	We agree that the available studies on degradation of 1,4-dioxane in soil are not sufficient to conclude on persistency in this compartment, especially due to the study of Kelley et al. (2001) showing the formation of CO2 from the substance under environmentally realistic conditions. Therefore, we change the conclusion as follows: “Considering the data on abiotic and biotic degradation, it is concluded that 1,4-dioxane is persistent and very persistent in the aquatic compartment.”  
	
		page 27: “It needs to be mentioned that the degradation half-life for water used in the worst-case scenario LRTP modelling is much lower than an experimentally determined DT50 higher than  10,000 days obtained in a simulation test according to OECD 309 (detailed in 3.1.2.1.3).”
comment: This needs to be modified as the DT50 of higher than 10 000 is a strong extrapolation from a 60-day study. The same comment applies to table 13.	Please see above for the changes we carried out in respect to the LRTP modelling and DT50.	
		page 27: “The POV boundary is 195 days (POV of α-HCH) and the LRTP boundaries are 5097 km (CTD of PCB 28) and 2.248 % (TE of PCB-28).”
comment: Please clarify the source/reference of the boundary values.	The requested reference for LRTP thresholds for Pov and CTD was added.
	
		page 30: Summary of LRTP.
comment: We propose to modify in line with previous comments regarding the half-life derived from the OECD TG 309 study.	We modified the summary of LRTP accordingly.	
		page 35: “Even while no specific degradation half-lives under environmental conditions were provided in these studies, they provide very strong evidence, that the substance can be rated as very persistent according to the criteria of REACH Annex XIII.”
comment: We propose to modify this, in line with our preceding comments regarding the strength of this evidence.	We modified the paragraph according to your comment.	
		page 35: “This previous hypothesis was confirmed by a simulation test on degradation in surface water (Hofman-Caris and Claßen, 2020), where a very high DT50 (SFO) ≥ 10,000 days was obtained for 1,4-dioxane. This value exceeds the threshold for very persistent substances in water (half-life in water higher than 60 days) according to the criteria of REACH Annex XIII by several orders of magnitude”

comment: We propose to modify this, so that the unnecessary reference to the hypothetical half-life is deleted, in line with our preceding comments	Page 35, summary:
We rephrased this summary section for clarification, clearly highlighting that aquatic half-life results from SFO kinetics estimate.
	
		page 35: “In overall conclusion and considering the available data on abiotic and biotic degradation, it is concluded that 1,4-dioxane is persistent and very persistent in the environment in the water compartment according to the criteria of REACH Annex XIII”
comment: Please delete “in the environment” as it seems unnecessary/unintentional here.	We deleted “in the environment” as suggested.
	
		page 25:” Quite the contrary, it is noticeable that 1,4-dioxane is still able to travel nearly 3000 km while predominantly staying in the water phase.”
comment: “nearly 3000 km” is based on the assumed half-life of 10000 days, which is a strong extrapolation from a 60-day study (water) or upper limit of EUSES (soil). We propose to modify the sentence.	Page 25, request for modification of the sentence:
already included information on p. 27, where the 10,000 day half-lives in water and soil result from. In addition, the mentioned source for the assumed SFO half-life of 10.000 days is repeated in the immediate follow-up in the summary. Therefore, we will not follow your request for reasons of avoiding redundancy/repetitions.
	
		page 37: “Due to the lack of abiotic and biotic degradation potential of 1,4-
dioxane and typically a co-presence of substances being degradable more easily, it is expected
that there is no removal by the sewage treatment plants and the overall amount of 1,4-dioxane releases to the environment is not reduced in sewage treatment plants.”

comment: Apparently, this sentence refers to wastewater treatment plants, and even in those there may be differences (e.g. between those treating municipal and industrial wastewater). The only cited article that is relevant to this matter is the one by Stepien et al (2014) and it concerns domestic sewage treatment plants. We propose to specify that the lack of biotic degradation potential here refers to domestic wastewater treatment plants also considering that, in general, biodegradation potential of the substance is known to exist.	Page 37: 
We added the following paragraph for clarification: “No information is available from studies that specifically investigate the degradation of 1,4-dioxane in industrial sewage treatment plants, which in general receive a mixture of various chemicals, too. A screening test on inherent biodegradation (OECD TG 302B) utilizing inoculum from an industrial sewage treatment plant showed removal of the substance from the test media (DOC monitoring), but this was a side effect of stripping the test vessels to determine the oxygen demand. Therefore, no evidence is available that biodegradation is a relevant step for removing 1,4-dioxane from waste water. Only those techniques which are also applied for drinking water purification seem to have some capacity to reduce the release of the substance into the environment (please see section 6.3.2.2.).” 
	
		page 38: “Mixture toxicity effects with other stressors cannot be ruled out”.
comment: Please consider if the mixture effects are necessary to mention in this SVHC proposal without further specification why this is relevant for 1,4-dioxane.  This argumentation would be the case generally for all persistent substances and not specifically for 1,4-dioxane. For example, in the SVHC dossier of Perfluorobutane sulfonic acid and its salts it was further specified that humans and the environment are exposed to a mixture of other PFASs.	Thank you for your comment on the mixture toxicity. We agree that the argument applies for most (or properly all) persistent substances. However, in the case for 1,4-dioxane we see that the argument is of relevance for 1,4-dioxane for mainly two reasons: 1. 1,4-Dioxane is found in monitoring studies along with a number of other substances (e.g. pharmaceuticals) in surface water and is found with chlorinated solvents and THF in ground water. 2. 1,4-dioxane is a solvent. E.g. there could be the possibility that 1,4-dioxane might modulate effects to organisms of co-occurring substances.	

5548
2021/04/23	Cefic,
Industry or trade association,
Belgium	Cefic comments are not related specifically to the targeted substance but mainly to the process applied to develop a SVHC dossier based on equivalent level of concern for human health /environment purposes. Please find enclosed a more detailed explanation on the concern raised.

In the argumentation presented in the dossier, at this stage it is unclear how to distinguish between environment and human health concerns and how the argument aligns to an Equivalent Level of Concern (ELoC). 

Additionally, in light of other information such as the Carcinogenic 1B classification of the substance and the conclusions of the Risk Management Options Analysis (RMOA) conducted prior to this Annex XV dossier, the added value of this identification under Article 57(f) is unclear. Finally, the approach taken in this dossier highlights some aspects of the REACH process which lack transparency and predictability and would benefit from a broader clarification.

Similarly, the ECJ ruling C‑323/15 P indicates that SVHC listing on grounds of Article 57(f) of REACH ("equivalence of concern") should consider hazards and exposure, i.e. the exposure characterisation due to the presence in the environment should not be used in isolation but rather in the risk assessment approach.

	Thank you for your comment which we addressed in the comment section “General comments on the SVHC proposal”. Specific comments are responded to below.

You commented that for the dossier it is unclear how to distinguish between environment and human health concerns. In our view, the case of 1,4-dioxane is an ideal case to demonstrate the interconnection, how human health benefits from a protected environment. The environment harbours the most important drinking water sources. Any violation of the integrity of the environment may cause adverse effects even to humans. In the specific case of 1,4-dioxane, classified as a carcinogen (Carc. 1B) according to CLP, this means: Avoiding 1,4-dioxane contamination of drinking water sources prevents unwanted human health effects. 

Concerning the lack of transparency and predictability, the conclusion document of the RMOA clearly stated our next steps (see: https://echa.europa.eu/documents/10162/010b37a1-9d0d-a69e-a703-df8626102fae). In that document, SVHC identification without subsequent authorisation but with subsequent restriction were presented as the next steps.

Contrary to the view expressed by CEFIC, it is the consistent case-law of the EU Courts that the identification of SVHC on the basis of Article 57(f) of REACH does not necessarily need to take into account information other than information on hazards arising from the intrinsic properties of a substance. In other words, it is a possibility, but not an obligation.
 
For instance, in Case T-636/17 the General Court  held in paragraph 121: 
“Generally, by providing that substances can be identified, on a case-by-case basis, if their serious effects on human health give rise to ‘an equivalent level of concern’ to that for those substances meeting the criteria for classification in the hazard classes carcinogenicity, mutagenicity or reproductive toxicity, Article 57(f) of Regulation No 1907/2006 does not prohibit the taking into consideration of data other than those relating to the hazards arising from the intrinsic properties of the substances concerned […] The latter ‘may include’, inter alia, the difficulty of adequately assessing the risks posed by those substances when it is impossible to determine, with the necessary certainty, a ‘derived no-effect level’ or a ‘predicted no-effect concentration’ (judgment of 15 March 2017, Hitachi Chemical Europe and Polynt v ECHA, C 324/15 P, EU:C:2017:208, paragraph 39). It follows that the migration limit of bisphenol A in certain objects, such as items intended to be in contact with food or toys, is a factor which ECHA can take into account for the purposes of identifying substances of very high concern, without that factor being decisive in that respect, and without it therefore being possible to conclude that the decision referring to such an identification is vitiated by a manifest error of assessment merely on account of a failure to take the permitted migration limit into account.”(underlining added)	
		See the corresponding embedded attachment in table 1 of Part I: 5548_2021 04_Cefic comment on ELoC SVHC identification.pdf		

PART II: Comments and responses to comments on uses, exposures, alternatives and risks

Specific comments on use, exposure, alternatives and risks
Number / Date	Submitted by (name, submitter type, country)	Comment	Responses	
5481
2021/04/22	BASF SE, 
Company,
Germany		Thank you for your comment. 	
		See the corresponding embedded attachment in table 1 of Part I: 5481_123-91-1_Final comment_BASF SE_20210422.pdf		
5496
2021/04/22	BASF Intermediates,
Company,
Germany		Thank you for your comment.	
		See the corresponding embedded attachment in table 1 of Part I: 5496_2021 04 15 Comment to the identification of dioxane as SVHC vers 3.pdf		
5502
2021/04/22	Netherlands,
Member State	Pages 19, 22, 35: In several parts of the document, reference is made to criteria for PMT/vPvM substances as described in Neumann and Schliebner (2019). We strongly suggest to remove this reference. In our view, meeting specific criteria is no prerequisite for any substance to be identified as an SVHC under ELoC; rather it is the combination of the elements of concern, assessed in a weight of evidence approach, that support ELoC to those of other substances listed under points (a) to (e) of Article 57 of REACH.	Thank you for your comment. We agree that defining criteria for the sake of SVHC identification under ELoC is not required and the current guidance is sufficient. 
The citation on page 19 is in our view not critical. Therefore, we did not remove it.
Page 22 & 35: We revised the text and removed the reference to the criteria when assessing the mobility of the substances.	
				
5510
2021/04/22	American Chemistry Council,
Industry or trade association,
United States of America	Please see attached comments	Thank you for your comment.	
		See the corresponding embedded attachment in table 1 of Part I: 5510_ACC comment on SVHC proposal for 1,4-dioxane - April 22.pdf		
5548
2021/04/23	Cefic,
Industry or trade association,
Belgium		Thank you for your comment.	
		See the corresponding embedded attachment in table 1 of Part I: 5548_2021 04_Cefic comment on ELoC SVHC identification.pdf