Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 219-137-4 | CAS number: 2370-88-9
- 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
In the key skin irritation study, a mixture of the two structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested for skin irritancy according to OECD Test Guideline 404 and in compliance with GLP. No signs of skin irritation were observed and the test mixture was concluded to be not irritating to skin (Dow Corning Corporation, 2001).
In the key eye irritation study, the mixture of structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested in an in vivo eye irritation test according to OECD Test Guideline 405 and in compliance with GLP. The mixture produced minimal conjunctival redness at 4, 24 and 48 hours fully reversible within 72 hours and the mixture was concluded to be not irritating to eyes (Dow Corning Corporation, 2002).
Both studies were done with mixture (approximately 50/50) of the structural analogues 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9).
Key value for chemical safety assessment
Skin irritation / corrosion
Link to relevant study records
- Endpoint:
- skin irritation: in vivo
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- Dec 18, 2000 to Jan 10, 2002
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
- Deviations:
- no
- Remarks:
- No sentinel animal, not yet required in 2001
- GLP compliance:
- yes (incl. QA statement)
- Specific details on test material used for the study:
- Test substance identified as mixture of 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) (45%) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) (54%) and the impurity 0.9% hexamethylcyclohexasiloxane.
- Species:
- rabbit
- Strain:
- New Zealand White
- Details on test animals or test system and environmental conditions:
- - three young adult females, at least 12 weeks old
- weight 3025g-3137g at initiation
- identification by eartag & cage card
- housed in individual suspended cages
- inspection upon arrival; acclimatisation for at least 7 days, observed twice daily
- Diet: Certifeid Rabbit LabDiet(r) 5322 ~a50 gr/animal/day. Tap water at lib. Food and water regularly analysed
- controlled temperature (69-71 degr. F), humidity (50-64%) light (12/12) and ventilation (10-15 changes / days) - Type of coverage:
- semiocclusive
- Preparation of test site:
- clipped
- Vehicle:
- unchanged (no vehicle)
- Controls:
- not required
- Amount / concentration applied:
- 0.5 ml / site
- Duration of treatment / exposure:
- 4 hours
- Observation period:
- 72 hours
- Number of animals:
- 3
- Details on study design:
- application to skin area approx 2.5 x 2.5, covered with 8-ply surgical gauze held in place with surgical porous tape. Overwrapped with gauze bandaging and secured with non-irritating tape; Animals were given restraint collars.
Duration of application 4 hours, after which bandages were removed and sites wiped clean with disposable paper towels moistened with deionized water. - Irritation parameter:
- erythema score
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritation parameter:
- erythema score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritation parameter:
- erythema score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritation parameter:
- edema score
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritation parameter:
- edema score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritation parameter:
- edema score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Remarks on result:
- no indication of irritation
- Irritant / corrosive response data:
- No animals showed any signs of irritation at any point in time
- Other effects:
- slight weight loss (,1%) in one animal, not uncommmon in animals of this weight range and strain; not considered to be substance-related
no mortality. - Interpretation of results:
- GHS criteria not met
- Conclusions:
- The mixture of structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) showed no signs of skin irritation.
- Executive summary:
A mixture of the two structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested for skin irritancy according to OECD 404 test method under GLP . The mixture showed no signs of skin irritation. Based on structural analogy, the conclusion applies directly to the registered substance as well as from read-across from the analogue.
Reference
Individual Irritation scores
Erythema |
Edema |
||||||||||
Animal nr. |
Sex |
1 hr |
24 hrs |
48 hrs |
72 hrs |
1 hr |
24 hrs |
48 hrs |
72 hrs |
||
34044 |
female |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||
34045 |
female |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||
34046 |
female |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
||
Total |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|||
PPI calculated for all timepoints: ppi = (0+0+0)/9 + (0+0+0) /9 = 0 + 0 = 0 |
Individual body weights (in grams):
Animal nr. |
Sex |
Initiation (day 0) |
Termination (day 3) |
34044 |
female |
3137 |
3289 |
34045 |
female |
3025 |
3067 |
34046 |
female |
3034 |
3020 |
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Eye irritation
Link to relevant study records
- Endpoint:
- eye irritation: in vivo
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- Dec 18, 1201 to Jan 10, 2002
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 405 (Acute Eye Irritation / Corrosion)
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Specific details on test material used for the study:
- Test substance identified as mixture of 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) (45%) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) (54%) and the impurity 0.9% hexamethylcyclohexasiloxane.
- Species:
- rabbit
- Strain:
- New Zealand White
- Details on test animals or tissues and environmental conditions:
- - three young adult rabbits, 2 females, one male, at least 12 weeks old
- weight 2531-2749 at study initiation
- identification by eartag & cage card
- housed in individual suspended cages
- inspection upon aarival; acclimatisation for at least 7 days, observed twice dayly
- Diet: Certified Rabbit LabDiet(r) 5322 ~a50 gr/animal/day. Tap water at lib. Food and water regularly analysed
- controlled temperature (69-71 degr. F), humidity (50-64%) light (12/12) and ventilation (10-15 changes / days) - Vehicle:
- unchanged (no vehicle)
- Controls:
- not required
- Amount / concentration applied:
- 0.1 ml /eye
- Duration of treatment / exposure:
- undefined. eyes were not washed at 1 hr post-treatment or later.
- Observation period (in vivo):
- 72 hours
- Number of animals or in vitro replicates:
- 3
- Details on study design:
- OBSERVATIONS
- twice daily for mortality
- body weights at beginning and end of study.
Ocular Observations:
before dosing and at 1, 24, 48 and 72 hrs, both eyes were observed by means of an ophthalmoscope for ocular abnormalities Pre-dosing and at 72 hrs observation included use of sodium fluoerescein for detection of corneal defects. Scoring according to Draize. Only animals without any ocular abnormalities were used in the study - Irritation parameter:
- cornea opacity score
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritation parameter:
- iris score
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 2
- Reversibility:
- other: not applicable
- Irritation parameter:
- conjunctivae score
- Remarks:
- redness
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0.7
- Max. score:
- 3
- Reversibility:
- not fully reversible within: 72 hrs
- Irritation parameter:
- chemosis score
- Basis:
- animal #1
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritation parameter:
- cornea opacity score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritation parameter:
- iris score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 2
- Reversibility:
- other: not applicable
- Irritation parameter:
- conjunctivae score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0.7
- Max. score:
- 3
- Reversibility:
- fully reversible within: 72 hrs
- Irritation parameter:
- chemosis score
- Basis:
- animal #2
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritation parameter:
- cornea opacity score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritation parameter:
- iris score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 2
- Reversibility:
- other: not applicable
- Irritation parameter:
- conjunctivae score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0.7
- Max. score:
- 3
- Reversibility:
- fully reversible within: 72 hrs
- Irritation parameter:
- chemosis score
- Basis:
- animal #3
- Time point:
- 24/48/72 h
- Score:
- 0
- Max. score:
- 4
- Reversibility:
- other: not applicable
- Irritant / corrosive response data:
- minimal redness of the coniunctivae in all animals at 4,24 and 48 hrs after instillation, completely reversible at 72 hrs
minimal chemosis at 4 hrs after instillation, completely reversible within 24 hrs - Other effects:
- No other effects were observed at any timepoint . No weight loss, no mortality
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- The mixture of structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) produced minimal conjunctival redness at 4, 24 and 48 hrs fully reversible within 72 hours. There were no other sings of irritation and the test material was concluded to be not irritating to eyes.
- Executive summary:
The mixture of structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested in an in vivo eye irritation test according to OECD 405 under GLP. The mixture produced minimal conjunctival redness at 4, 24 and 48 hrs and minimal chemosis at 4 hrs, all fully reversible. The conclusion applies directly to the registered substance as well as indirectly by read-across from the structural analogue which is also present in the mixture.
Reference
Individual scores and mean scores over 24,48 an d 72 hrs:
1 hr |
24 hr |
48 hr |
72 hr |
Mean score 24,48,72 hrs |
||
Animal nr 34586, M |
Cornea opacity |
0 |
0 |
0 |
0 |
0 |
Cornea area |
0 |
0 |
0 |
0 |
0 |
|
Iris |
0 |
0 |
0 |
0 |
0 |
|
Conjunctivae redness |
1 |
1 |
1 |
0 |
0,7 |
|
Conjunctivae chemosis |
1 |
0 |
0 |
0 |
0 |
|
Conjunctivae discharge |
0 |
0 |
0 |
0 |
0 |
|
Animal nr. 34595, F |
Cornea opacity |
0 |
0 |
0 |
0 |
0 |
Cornea area |
0 |
0 |
0 |
0 |
0 |
|
Iris |
0 |
0 |
0 |
0 |
0 |
|
Conjunctivae redness |
1 |
1 |
1 |
0 |
0,7 |
|
Conjunctivae chemosis |
1 |
0 |
0 |
0 |
0 |
|
Conjunctivae discharge |
0 |
0 |
0 |
0 |
0 |
|
Animal nr. 34594, F |
Cornea opacity |
0 |
0 |
0 |
0 |
0 |
Cornea area |
0 |
0 |
0 |
0 |
0 |
|
Iris |
0 |
0 |
0 |
0 |
0 |
|
Conjunctivae redness |
1 |
1 |
1 |
0 |
0,7 |
|
Conjunctivae chemosis |
1 |
0 |
0 |
0 |
0 |
|
Conjunctivae discharge |
0 |
0 |
0 |
0 |
0 |
Individual body weights:
Animal nr |
Sex |
At initation |
At 72 hrs |
34586 |
male |
2744 |
2834 |
34596 |
Female |
2531 |
2720 |
34594 |
Female |
2684 |
2695 |
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not irritating)
Respiratory irritation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
In the key skin irritation study, a mixture of the two structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested for skin irritancy according to OECD Test Guideline 404 and in compliance with GLP (Dow Corning Corporation, 2001).
Following single topical application of the mixture 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) to the skin of 3 rabbits, showed no signs of erythema or edema. No signs of skin irritation were observed and the test mixture was concluded to be not irritating to skin.
In the key eye irritation study, the mixture of structurally analogous substances 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) was tested in an in vivo eye irritation test according to OECD Test Guideline 405 and in compliance with GLP (Dow Corning Corporation, 2002).
Following single instillation of 0.1 ml of the mixture 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9) to the eyes of 3 rabbits showed minimal conjunctival irritation which was reversible within 72 hours. No other signs of eye irritation were observed during the 72-hour observation period. The test material was concluded to be not irritating to eyes.
See attachment to IUCLID Section 13 for justification of using data for the mixture of 2,4,6,8,10-pentamethylcyclopentasiloxane (CAS 6166-86-5) and 2,4,6,8-tetramethylcyclotetrasiloxane (CAS 2370-88-9).
Justification for classification or non-classification
Based on the available read-across data, 2,4,6,8-tetramethylcyclotetrasiloxane does not require classification for skin or eye irritation according to 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.
![ECHA](/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/echa_logo.png)