Comments on ECHA’s Draft 12th Recommendation for Barium diboron tetraoxide (EC number: 237-222-4) and references to responses

The present document compiles the comments received during the public consultation on the draft 12th recommendation for inclusion of substances in Annex XIV of REACH for Barium diboron tetraoxide (EC number: 237-222-4). The public consultation took place between 7 February 2024 and 7 May 2024. Response to the comments received will be provided by ECHA when finalising the recommendation (indicative timeline: April 2025).

Public version

Content
	
I - General comments on the recommendation to include the substance in Annex XIV
II - Transitional arrangements. Comments on the proposed dates
III - Comments on uses that should be exempted from authorisation, including reasons for that

I - General comments on the recommendation to include the substance in Annex XIV
Number / Date	Submitted by (name, submitter type, country)	Comment	
5137
2024/05/06	Aerospace Industries Association of America,
Industry or trade association,
United States of America	We understand that REACH registrations are the main source of information for ECHA's assessment.  However, uses in the aerospace sector are typically small and may not be fully reflected in registration dossiers.  This can be especially true of imports of specialty formulations where the tonnage may fall well below registration thresholds, but that provide critical functionality needed by our industry and its products.
AIA member companies rely on Barium diboron tetraoxide in products and formulations for the manufacture, maintenance and repair of aerospace and defense products.  Identified aerospace uses include the following uses
• Polymer epoxy sealants
• Epoxy underlayment coatings
• Silicon hybrid resin coatings
• Industrial primers, paints and enamels
• Non-skid deck coating

5146
2024/05/07	NV Buckman Laboratories,
Company,
Belgium	a) Lower Tonnage Band must be used in Prioritisation
The draft background document prepared by ECHA indicates at section 2.2 that the amount of barium diboron tetraoxide manufactured and/or imported into the EU is  in the range of 100 –1,000 t/y according to registration data (ECHA, 2023).

However, the registration dossier was updated in January 2024 and the relevant tonnage band relevant for the background document is 10-100 tonnes per annum.

This lower tonnage has the effect of lowering the volume prioritisation score and total prioritisation score by 3 to 19.

b) Proposed grouping approach for other borates not justified for barium diboron tetraoxide
The draft background document says prioritisation of barium diboron tetraoxide for inclusion on Annex XIV is based on grouping with other borate substances that have already been included on the candidate list and/or Annex XIV REACH.  However, it is important to note that grouping of barium diboron tetraoxide with other borates is not appropriate for the following reasons:

• Barium diboron tetraoxide has a far lower solubility (more than 20 times less soluble) in water (822mg/l at 25oC, no available data at 20oC) than other borates on the Candidate List or Annex XIV (typically 20-225g/l at 20oC).  See Table 1 (in the attachment) for solubility information.  The bioavailability and toxicological effects of barium diboron tetraoxide are therefore expected to be less significant on a boron equivalent basis. For this reason, read-across from borates to barium diboron tetraoxide or vice versa is not appropriate.

• While information in the background documents/Annex XV dossiers indicates many borate substances are used (as corrosion inhibitors) in coatings, sealants and paints, barium diboron tetraoxide has different properties and hence is used in different applications in which it cannot be replaced with the other borates on the candidate list/Annex XIV. In particular, the different counter ion (barium versus sodium), the low solubility of barium diboron tetraoxide and the electrochemical properties related to the barium cation means that barium diboron tetraoxide is specified in high performance coating and paint formulations, especially where it is necessary to assure long-lasting protection from corrosion and other destructive mechanisms to meet safety requirements under highly challenging environmental conditions. The low solubility of barium diboron tetraoxide allows the dried paint film to maintain its corrosion inhibition for a long time .  On the other hand, the more soluble borates, while sometimes used in paints as corrosion inhibitors, migrate into the aqueous environment more quickly after application so do not provide long-term protection. For this reason, these borates are more often used for the prevention of in-can corrosion whereas barium diboron tetraoxide is not. Barium diboron tetraoxide could not be a replacement for borax and other water-soluble borates because of its low solubility.

• While there may be similarities in some properties (e.g. melting temperature and state) and functionalities (e.g.flame resistance) of barium diboron tetraoxide and boric acid, the differences in properties such as solubility are such that they cannot be considered similar.

• Other uses of barium diboron tetraoxide including coating to electrical wire are not uses for other borates on the candidate list, again indicating these substances are not interchangeable.

In summary, the prioritisation of barium diboron tetraoxide should be adjusted in the background document:

• The prioritisation scoring should be 9 on the basis of the lower tonnage band
• It should not be grouped with the other borates already on the Candidate List due to its far lower solubility and expected lower bioavailability.

On this basis, it would no longer be appropriate for ECHA to prioritise or recommend the substance for inclusion on Annex XIV.
	
		5146_barium diboron tetraoxide recom_echa_comments_questionnaire_en Buckman Table 1.docx
	
5151
2024/05/07	European Aerospace, Security and Defence Industries Association (ASD) ,
Industry or trade association,
Belgium	ASD members have indicated the use of Barium diboron tetraoxide in a number of mixtures and formulations including adhesives, paints, lubricants, epoxy-based fillers.	

II - Transitional arrangements. Comments on the proposed dates
Number / Date	Submitted by (name, submitter type, country)	Comment	
5137
2024/05/06	Aerospace Industries Association of America,
Industry or trade association,
United States of America	At this stage of assessment AIA member companies (comprising mainly OEMs) consider that Authorisation may be required for some uses of barium diboron tetraoxide until alternatives can be developed, qualified and substituted.  AIA envisages that our member companies would actively support development and submission of applications for Authorisationfor their uses where they do not have alternatives.  Members would not necessarily seek Authorisation themselves but rather as part of joint upstream applications.  Upstream applications supported by OEMs are essential for business continuity in the aerospace sector.  Aerospace and defense (A&D) supply chains are complex and typically global with many actors at different levels.  OEMs control the end user requirements for the products they produce.  Upstream actors in the chemical supply chain (e.g. formulators, importers of formulations), however, are better placed to hold Authorisations and distribute chemicals to the various users (e.g. processors, component manufactures, OEMs, etc.) of the substances.

The main challenge in preparing an upstream application is obtaining detailed information about site operations for lower tier suppliers of OEMs.  A typical A&D sector supply chain may have four or five or more tiers or levels of companies that supply each other.  Each tier of the supply chain is responsible for establishing contracts with lower tiers to obtain products that meet their requirements, but they rarely share sensitive business information (such as supplier identity) with higher-tier suppliers or the OEM that can inhibit their competitiveness.  This structure allows for the deliberate flow of requirements, but not of sensitive business information (such as employee exposure data, socioeconomic business date, etc.) essential for Authorisation applications.  The A&D sector relies instead on surveys and encourages affected downstream users (DUs) to collaborate in Authorisation consortia (by joining or contributing) and voluntarily provide relevant data to third party consultants that aggregate the available data.  This approach is both time consuming and dependent on supplier cooperation.  In the short 18 to 24 month timeframe after substance listing on Annex XIV and the Last Application Date there is not always sufficient time to encourage enough supply chain actors to gather the pertinent data and develop a solid application.

Because of the many supply chain actors that need to be coordinated we strongly suggest that a longer transition period be adopted (i.e.. at least 24 months).

5146
2024/05/07	NV Buckman Laboratories,
Company,
Belgium	Clarifying information in the draft background document prepared by ECHA, barium diboron tetraoxide is imported to the EU by only one registrant.  The substance is sold in the EU via distributers.  The number of downstream users is not known.

Uses of barium diboron tetraoxide known to this registrant include a constituent of specialty coatings, paints, sealants, coating of electrical wire and plastic industrial electrical cabling (polymer preparations and compounds) and adhesive tape.

Use as thinners, paint removers is not known to be carried out. Inclusion of these product types appears to be an artefact of reference to product category 9a (PC 9a: Coatings and paints, thinners, paint removes) in the REACH registration dossier.

As explained in response to the previous question, use of barium diboron tetraoxide is not interchangeable with other borates on the Candidate List / Annex XIV due to its far lower aqueous solubility and influence of the barium cation on the molecule.  Other borates might be used in paints and coatings, but the specialty paints and coatings in which barium diboron tetraoxide is used have unique applications.   Barium diboron tetraoxide is a constituent of paints and coatings that must meet exacting standards over long time periods and the most challenging environments, such as military applications, shipping, and constructions such as bridges and rebars, where performance and safety cannot be compromised.

For these uses, the supply chain generally as follows: chemical importer - chemical distributor - formulator - formulation distributor - industrial or professional user.  The supply chain for uses such as electrical cable coating and adhesive / tape are  expected to be similar, eg: chemical importer - chemical distributor - article manufacturer - article distributor -industrial or professional user.

Information on the number of potential industrial and professional users that have qualified and rely on these formulations is not available.  However, given the broad range of applications expected, the time to organise actors in and gather information across the supply chain, and the significant potential safety implications of failing to secure continuous use when a robust application for authorisation cannot be filed prior to the LAD, it is clear that an adequate timeframe is needed to prepare and submit a robust AfA.
Concern over an inadequate LAD is exacerbated if (despite evidence above), ECHA elects to include barium diboron tetraoxide within a borate group to be included in Annex XIV.  In this instance, when the number of authorisations would be even greater, it would be critical that barium diboron tetraoxide receives a long LAD.

Based on the broad range of applications expected, the time to organise actors in and gather information across the supply chain, and the significant potential safety implications of failing to secure continuous use when a robust application for authorisation cannot be filed prior to the LAD, an extended LAD of 24 months would be necessary.

If, despite objections, ECHA elects to include barium diboron tetraoxide within a borate group to be included in Annex XIV, barium diboron tetraoxide should receive a long LAD.
	
		5146_barium diboron tetraoxide recom_echa_comments_questionnaire_en Buckman Table 1.docx
	
5151
2024/05/07	European Aerospace, Security and Defence Industries Association (ASD) ,
Industry or trade association,
Belgium	In some cases (e.g. members indicate for some specific uses of epoxy-based fillers) there are already potential alternative formulations, that could be developed and qualified for introduction. However, these are not also without concern since they also rely on bisphenols (the subject of an ongoing restriction proposal) and substances included in the recent restriction call for evidence for brominated flame retardants.
Particular challenges foreseen for alternatives development and introduction concern viability of reformulations to replace the barium diboron tetraoxide in cases where it is still unclear how other substances required for those formulations will be managed under possible REACH restrictions - bisphenols and brominated flame retardants.
It is considered challenging to meet the early (18-month LAD) timescale for the aerospace industry as no there are currently no equivalent (developed and qualified) alternatives available nor likely to be available in the near term. Hence, if not exempted or granted a longer LAD, Authorisations for the sector would be required. Based on prior sector experience for developing Authorisation submissions for other substances, typically ca. 2+ years is required to develop the necessary dossiers prior to submission. Sufficient timelines for industry to be able to develop required dossiers must be provided for to ensure continuity of the value chain. For cases where alternatives already identified may be able to be qualified for use in the short term (ca. 5 years), sufficient time to carry out the necessary testing and implementation would be required prior to the LAD, to avoid the need for short Authorisation requests.	

III - Comments on uses that should be exempted from authorisation, including reasons for that
Number / Date	Submitted by (name, submitter type, country)	Comment	
5146
2024/05/07	NV Buckman Laboratories,
Company,
Belgium	No comment	
		5146_barium diboron tetraoxide recom_echa_comments_questionnaire_en Buckman Table 1.docx
	
5151
2024/05/07	European Aerospace, Security and Defence Industries Association (ASD) ,
Industry or trade association,
Belgium	Any potential exemption should take into account that the viability of identified alternatives would depend on the long-term ability to use other substances under regulatory scrutiny that are needed to develop them (mainly bisphenols).