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EC number: 217-496-1 | CAS number: 1873-88-7
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
![](https://echa.europa.eu./o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
Endpoint summary
Administrative data
Description of key information
The key study for acute oral toxicity reports an LD50 value greater than 2000 mg/kg bw which was determined in a reliable study with 1,1,1,3,5,5,5-heptamethyltrisiloxane (H-L3), carried out in accordance with OECD Test Guideline 425 and in compliance with GLP (RCC 2008).
The acute inhalation study is read across from octamethyltrisiloxane (L3, CAS 107-51-7). The animals were exposed to vapour and an LC50 value greater than 22.6 mg/l (analytical) was determined in a reliable study conducted according to OECD Test Guideline 403 and in compliance with GLP (Dow Corning 2004).
In addition, a study was conducted according to OECD Test Guideline 403 and in compliance with GLP for the read-across substance 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7). The animals were exposure to vapour and an LC50 value greater than 5.8 mg/l (measured) was determined (Dow Corning Corporation, 1994).
In accordance with Column 2 of REACH Annex VIII, the acute toxicity study via the dermal route (required in Section 8.5.2) does not need to be conducted as reliable data via the oral and inhalation routes are available.
Key value for chemical safety assessment
Acute toxicity: via oral route
Link to relevant study records
- Endpoint:
- acute toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 2008
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)
- Version / remarks:
- 2001
- Qualifier:
- according to guideline
- Guideline:
- EPA OPPTS 870.1100 (Acute Oral Toxicity)
- Version / remarks:
- 2002
- GLP compliance:
- yes
- Test type:
- up-and-down procedure
- Limit test:
- yes
- Species:
- rat
- Strain:
- other: HanRcc:WIST (SPF)
- Sex:
- female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: RCC Ltd., Switzerland
- Females: yes, nulliparous and non-pregnant
- Age at study initiation: 11 - 12 weeks
- Weight at study initiation: 176.5 - 199.5 g
- Fasting period before study: yes, 16 to 18 hours (access to water was permitted, food was provided again approximately 3 hours after dosing)
- Housing: Individually in Makrolon type-3 cages with wire mesh tops and standard softwood bedding
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: yes, but time period not specified in report
ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3 °C
- Humidity: 30-70 %
- Air changes : 10-15 air exchanges/hour
- Photoperiod: 12 hours dark/ 12 hours light - Route of administration:
- oral: gavage
- Vehicle:
- corn oil
- Details on oral exposure:
- VEHICLE
- Concentration in vehicle: 0.2 g/ml
- Justification for choice of vehicle: The vehicle was chosen after a non-solubility trial which was performed before the study initiation date. This formulation trial is excluded from the statement of compliance. The test item prepared in corn oil was well-soluble.
- Lot/batch no. (if required): 18787208
MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg
DOSAGE PREPARATION: The dose formulations were made shortly before dosing using a magnetic stirrer as homogenizer. The sample was shaken thoroughly before each handling. The test item was weighted into a tared glass beaker on a suitable precision balance and the vehicle (corn oil) added. Homogeneity of the test item was maintained during dose administration using a magnetic stirrer. - Doses:
- 2000 mg/kg bw
- No. of animals per sex per dose:
- 5
- Control animals:
- no
- Details on study design:
- - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were examined daily during the acclimation period and mortality; viability and clinical signs were recorded. All animals were examined for mortality/viability and clinical signs within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once (twice for mortality/viability) daily during test days 2-15. Body weights were recorded on test day 1 (prior to removal of food), on test days 1 (prior to administration) 8 and 15. All animals were necropsied and examined macroscopically.
- Necropsy of survivors performed: yes - Key result
- Sex:
- female
- Dose descriptor:
- LD50
- Effect level:
- > 2 000 mg/kg bw
- Based on:
- dissolved
- Remarks on result:
- not determinable due to absence of adverse toxic effects
- Mortality:
- All animals survived until the end of the study period.
- Clinical signs:
- other: Slightly to moderately ruffled fur was noted in all animals from the 1- or 5- hour reading up to test day 2 or 3, with persisting in one animal through test day 7. Slight to marked sedation was recorded in all animals from the 2-, 3- or 5-hour observation
- Gross pathology:
- No macroscopic findings were recorded at necropsy.
- Other findings:
- None reported.
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- An LD50 value greater than 2000 mg/kg was determined in a reliable study conducted according to OECD 425 and in compliance with GLP.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LD50
- Value:
- 2 000 mg/kg bw
Acute toxicity: via inhalation route
Link to relevant study records
- Endpoint:
- acute toxicity: inhalation
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 9 April 2004 - 23 June 2004
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 403 (Acute Inhalation Toxicity)
- Principles of method if other than guideline:
- Mass median aerodynamic diameter / Geometric st. dev. not reported.
- GLP compliance:
- yes (incl. QA statement)
- Test type:
- standard acute method
- Limit test:
- yes
- Species:
- rat
- Strain:
- Crj: CD(SD)
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Age at study initiation: 9 weeks at experimental start
- Weight at study initiation: females 199.4-208.2 g, males 295-310 g
- Housing: wire-mesh cages
- Diet: certified rodent chow, ad libitum
- Water: municipal water, ad libitum
- Acclimation period: 7 days
ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3 °C
- Humidity: 30-70 %
- Air changes : 10-15 air exchanges/hour
- Photoperiod : 12 hours dark/ 12 hours light - Route of administration:
- inhalation: vapour
- Type of inhalation exposure:
- whole body
- Vehicle:
- air
- Details on inhalation exposure:
- GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure chamber volume: 450 litres
- Method of holding animals in test chamber: The animals were positioned within stainless steel exposure caging specifically designed for use in the 450 litre chamber (two levels of 10 wire mesh cages).
- Source and rate of air: Nash Air Compressor (Model/Size: AL-574), air sourced from building air supply
- Method of conditioning air: Conditioned building air was passed through HEPA and activated charcoal filters before delivery to the chamber. The compressed air was passed through a series of filters to remove contaminants (Matheson model: 460/461 and Balston model 100-18-DX and 100-18-BX) prior to use in test atmosphere. Chamber atmosphere consisted of a dilution air stream and a octamethyltrisiloxane vapour/carrier stream. The dilution air stream was building-conditioned air (i.e. warmed and humidified) passed through activated carbon and HEPA filters. The carrier air stream was compressed air passed through a series of particulate filters prior to use in vapour generation.
- System of generating particulates/aerosols: Generation of test article vapour concentration was performed using a heated stainless steel J-tube containing a column of stainless steel beads. Test article was metered from a reservoir into the J-tube using a pump. Compressed air flowed through the J-tube at a controlled rate of 34.8 l/minute. The carrier/vapour mixture passed from the J-tube to the inlet port at the top of the exposure chamber. Just prior to entering the exposure chamber, the carrier/vapour mixture combined with chamber supply air (dilution air) and was diluted to the target chamber concentration as it enters the exposure chamber.
- Method of particle size determination: no data
- Treatment of exhaust air: no data
- Temperature, humidity, pressure in air chamber: The exposure chamber was operated under dynamic conditions with regard to airflow, temperature, relative humidity and pressure. Chamber temperature was maintained within the range of 22.1-25.8°C. Chamber relative humidity was maintained within the range of 31.7%-46.6%, Chamber airflow, temperature and percent relative humidity were monitored continuously and recorded at approximately thirty-minute intervals.
TEST ATMOSPHERE
- Brief description of analytical method used: Test atmosphere oxygen content was measured once during the exposure period. The test article reservoir weight was determined pre- and post-exposure. These data, along with the chamber airflow rate and the vapour generation time, were used to calculate a nominal chamber concentration of test article. Chamber atmosphere was analysed using a Varian 3400 gas chromatograph equipped with a flame ionization detector (GC/ID) to determine the actual chamber concertation of test article. The concentration of test article in the chamber atmosphere during exposure period was evaluated approximately every 30 minutes. A continuously purged sample line was used to transfer a sample of the chamber atmosphere to the GC/FID for analysis.
- Samples taken from breathing zone: yes
TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: no data
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): no data - Analytical verification of test atmosphere concentrations:
- yes
- Duration of exposure:
- 4 h
- Remarks on duration:
- plus one 20 minute chamber equilibration time
- Concentrations:
- Measured 2350 ppm (22.6 mg/l)
Nominal 2448 ppm (23.5 mg/l) - No. of animals per sex per dose:
- 5 male, 5 female
- Control animals:
- no
- Details on study design:
- - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality and morbidity were observed twice daily during the week and once daily on weekends. Following the exposure, animals were evaluated once daily for clinical signs. Individual body weights were collected prior to exposure for randomization. Following randomization, body weights were recorded on day 1 (prior to exposure), day 8, and day 15 (prior to terminal sacrifice).
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: Complete gross pathology was carried out, no tissues were saved. - Key result
- Sex:
- male/female
- Dose descriptor:
- LC50
- Effect level:
- > 22.6 mg/L air (analytical)
- Based on:
- test mat.
- Exp. duration:
- 4 h
- Mortality:
- There were no mortalities.
- Clinical signs:
- other: There were no clinical signs.
- Body weight:
- All body weights and weight gains were considered normal for both sexes.
- Gross pathology:
- There were no macroscopic abnormalities.
- Other findings:
- None reported.
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- An LC50 value greater than 22.6 mg/l (analytical) was determined for the read-across substance octamethyltrisiloxane (L3, CAS 107-51-7) in a reliable study conducted according to the OECD Test Guideline 403 and in compliance with GLP.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed
- Dose descriptor:
- LC50
- Value:
- 22 600 mg/m³ air
Acute toxicity: via dermal route
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
The key study for acute oral toxicity reported an LD50 value greater than 2000 mg/kg bw in rat, in a reliable study conducted according to OECD Test Guideline 425 and in compliance with GLP (RCC 2008). There were no mortalities during the study period. Slightly to moderately ruffled fur was noted in all animals from the 1- or 5- hour reading up to test day 2 or 3, persisting in one animal through test day 7. Slight to marked sedation was recorded in all animals from the 2-, 3- or 5-hour observation up to 5 hours post-dose or test days 2 or 3. Two animals showed slightly poor coordination on test day 2 only, while two other animals showed slight to markedly or slightly to moderately poor coordination from 5 hours post-dose until test day 2. Hunched posture was observed in four animals at the 1-hour reading and persisted through the 5-hour evaluation in one animal and through test day 2 in three animals. Ventral recumbency was noted in one animal on test day 2. The body weight of animals was within normal range. No macroscopic findings were recorded at necropsy.
The key study for acute inhalation was read across from the related substance octamethyltrisiloxane (L3, CAS 107-51-7). The study was conducted according to the OECD Test Guideline 403, and in compliance with GLP. The reported LC50 value is greater than 22.6 mg/l (Dow Corning 2004). There were no mortalities, no clinical signs or macroscopic abnormalities reported at necropsy. Furthermore, all body weight gains were considered normal for both sexes.
Read across was also included for acute inhalation from another related substance 1,1,3,3-tetramethyldisiloxane (H2 -L2, CAS 3277-26-7).
The study was conducted according to the OECD Test Guideline 403, and in compliance with GLP. No toxicity was found when male and female rats were exposed for 4 hours to a measured atmosphere containing 5.8 mg/l (vapour) of the test material. The LC50 would exceed this value. There were no treatment-related abnormalities reported. Clinical signs of rapid respiration and salivation were recorded. There were no mortalities (Dow Corning Corporation, 1994).
Justification for classification or non-classification
Based on the available information, 1,1,1,3,5,5,5-heptamethyltrisiloxane(H-L3) does not require classification for acute toxicity in accordance with Regulation (EC) No 1272/2008.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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