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EC number: 203-499-5 | CAS number: 107-52-8
- 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
Endpoint summary
Administrative data
Description of key information
The key study for skin irritation is read across from a structurally analogous substance octamethyltrisiloxane (CAS 107-51-7). The study, conducted according to OECD TG 406, and in compliance with GLP, reports the test material to be not sensitising to skin (RCC, 1999).
Key value for chemical safety assessment
Skin sensitisation
Link to relevant study records
- Endpoint:
- skin sensitisation: in vivo (non-LLNA)
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 01 Dec 1998 - 15 Feb 1999
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 406 (Skin Sensitisation)
- Qualifier:
- according to guideline
- Guideline:
- EU Method B.6 (Skin Sensitisation)
- GLP compliance:
- yes (incl. QA statement)
- Type of study:
- guinea pig maximisation test
- Justification for non-LLNA method:
- An LLNA study was not performed because there is an existing reliable study for skin sensitisation using the Buehler/Guinea Pig Maximisation test method. Furthermore, the LLNA test method is not considered to be suitable for substances that contain silicon. Please refer to the attached document for further details.
- Species:
- guinea pig
- Strain:
- other: Ibm: GOHI; SPF- quality guinea pigs
- Sex:
- male/female
- Details on test animals and environmental conditions:
- TEST ANIMALS
- Source: RCC Ltd, Biotechnology & Animal Breeding Division, Wolferstrasse 4, CH-4414 Fullinsdorf, Switzerland
- Age at study initiation: 5-7 weeks
- Weight at beginning of acclimation period: 304-380 g
- Housing: Individually in Makrolon type-4 cages with standard softwood bedding
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: One week for the control and test group under test conditions after health examination. No acclimation of animals of the pretest. Only animals without any visible signs of illness were used.
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12 - Route:
- intradermal and epicutaneous
- Vehicle:
- olive oil
- Concentration / amount:
- Induction 100%, challenge 50%, positive control: intradermal induction 5% , epidermal induction 50% , challenge 50% (vehicle mineral oil)
- Route:
- epicutaneous, occlusive
- Vehicle:
- olive oil
- Concentration / amount:
- Induction 100%, challenge 50%, positive control: intradermal induction 5% , epidermal induction 50% , challenge 50% (vehicle mineral oil)
- No. of animals per dose:
- Control group: 5
Test group: 10
Intradermal pretest: 1
Epidermal pretest: 2
Positive control: 10 test, 5 control - Details on study design:
- PRE TEST: This was carried out to identify a suitable concentration of the test article for the induction phase of the main study and a non-irritant concentration for the challenge phase. The concentrations tested were for the epidermal application the most qualified to assure an optimum technical application procedure and for the intradermal injection the selected concentrations were tested at 1, 3 and 5%.
MAIN STUDY:
INTRADERMAL INJECTIONS (DAY 1)
Three pairs of intradermal injections (0.1 ml/sire) were made at the border of a 4x6 cm area in the clipped region as follows:
TEST GROUP:
1. 1:1 (v/v) mixture of FCA and physiological saline.
2. The test article, at 5% in olive oil.
3. The test article at 5% in a 1:1 (v/v) mixture of FCA and physiological saline
CONTROL GROUP:
1. 1:1 (v/v) mixture of FCA and physiological saline.
2. Olive oil.
3. 1:1 (w/w) mixture of olive oil in a 1:1 (v/v) mixture of FCA and physiological saline.
EPIDERMAL APPLICATIONS (DAY 8)
TEST GROUP:
One week after the injections the scapular area was shaved free of hair again prior to the epidermal application. Filter paper was saturated with the undiluted test material and placed over the injection sites of the test animals. The volume of the test article was ca. 0.3 ml. The patch was covered with aluminium foil and firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with impervious adhesive tape. The dressings were left in place for 48 hours. The epidermal application procedure described ensured intensive contact of the test article. The reaction sites were assessed for erythema and oedema 24 and 48 hours after removal of the dressing, using the numerical grading system according to Draize.
CONTROL GROUP:
The guinea pigs of the control group were treated as described above with olive oil only, also applied at a volume of ca. 0.3 ml.
CHALLENGE TEST (DAY 22)
The test and control animals were challenged two weeks after the epidermal induction application. The test and control guinea pigs were treated in the same way.
Hair was clipped and shaved from a 5x5 cm area on the left and right flank of each guinea pig just prior to application. Two patches of filter paper were saturated with the test article at the highest non-irritating concentration of 50% (left flank) and the vehicle only (olive oil applied to the right flank) using the same method as for the epidermal application. The volume of test article or vehicle applied was approximately 0.2 ml. The dressings were left in place for 24 hours.
After ca. 21 hours after removal of the dressing the test sites treated with the test article were depilated as described in the epidermal pretest. Approximately 24 and 48 hours after the removal of the dressing the application sites were assessed for erythema and oedema using the numerical scoring system according to Draize. - Challenge controls:
- Challenge controls were treated in the same way as the test group.
- Positive control substance(s):
- yes
- Remarks:
- 2-mercaptobenzothiazole
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- test chemical
- Dose level:
- 50% in olive oil
- No. with + reactions:
- 0
- Total no. in group:
- 10
- Remarks on result:
- no indication of skin sensitisation
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- test chemical
- Dose level:
- 50% in olive oil
- No. with + reactions:
- 0
- Total no. in group:
- 10
- Remarks on result:
- no indication of skin sensitisation
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- positive control
- Dose level:
- 10%
- No. with + reactions:
- 9
- Total no. in group:
- 10
- Remarks on result:
- positive indication of skin sensitisation
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- positive control
- Dose level:
- 10%
- No. with + reactions:
- 10
- Total no. in group:
- 10
- Remarks on result:
- positive indication of skin sensitisation
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- negative control
- Dose level:
- 50% in olive oil
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- negative control
- Dose level:
- 50% in olive oil
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- The test material was found not sensitising in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.
Reference
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not sensitising)
- Additional information:
The key study for skin sensitisation is read across from a structurally analogous substance octamethyltrisiloxane (L3, CAS 107-51-7). The study, conducted according to OECD TG 406, and in compliance with GLP, reports the test material to be not sensitising to skin (RCC, 1999).
At induction, 0.3 ml of undiluted test material was applied epidermally onto the scapular area of 10 guinea pigs. The area was shaved prior to application. The test material was kept in contact to the skin by occlusive dressing for 48 hours. The reaction sites were assessed for erythema and oedema 24 and 48 hours after removal of the dressing, using the numerical grading system according to Draize. 0.3 ml of olive oil was applied onto the skin of the 5 control guinea pigs.
At challenge, 0.2 ml of 50 % of the test material in olive oil was applied onto the flanks of 10 test guinea pigs and kept in contact to the skin under occlusive dressing for 24 hours. The area was shaved prior to application. Approximately 24 and 48 hours after the removal of the dressing the application sites were assessed for erythema and oedema using the numerical scoring system according to Draize. Olive oil was applied onto the skin of the 5 control guinea pigs. No signs of erythema or oedema were observed at 24 and 48 hours post-application. Expected reactions were observed in the positive and negative control groups.
READ-ACROSS JUSTIFICATION
To reduce animal testing REACH recommends to make use of a read-across approach where appropriate based on the high accordance in properties relevant for the specific endpoint. In the case of sensitisation relevant properties are structural similarity, hydrolysis rate and the physical-chemical parameters in the same range. In the following paragraphs the proposed read-across is discussed. Further information can be found in the supporting report (PFA, 2013u) attached in Section 13 of the IUCLID 6 dossier.
Read-across hypothesis
The hypothesis is that the target (registered) source substance and the (read-across) substances have similar toxicological properties because they are linear siloxanes with similar physicochemical properties and are structurally similar with similar hydrolysis rates so have similar toxicological properties.
a) Structural similarity
Tetradecamethylhexasiloxane (L6) is a methyl-substituted linear siloxane, with six silicon atoms connected by five oxygen atoms, in which the Si-O bonds are susceptible to hydrolysis. Octamethyltrisiloxane (L3) is also a methyl substituted linear siloxane, with three silicon atoms and two oxygen atoms.
b) Similar physicochemical properties
The linear siloxanes all have high log Kow (increasing with increasing chain length) and low water solubility.
c) Similar hydrolysis rates
The linear siloxanes all hydrolyse slowly at neutral pH.
Summary of key sensitisation data for linear siloxanes
Substance
L2
L3
L4
L5
L6
Chemical name
Hexamethyl
disiloxane
Octamethyl
trisiloxane
Decamethyl
tetrasiloxane
Dodecamethyl
pentasiloxane
Tetradecamethyl
hexasiloxane
CAS number
107-46-0
107-51-7
141-62-8
141-63-9
107-52-8
Skin sensitising result
Not sensitising (Dow Corning Corporation, 1992)
Not sensitising (RCC, 1999)
-
-
-
Reference
Dow Corning Corporation (1992). Human repeated insult patch test with hexamethyldisiloxane. TKL Research, USA. Report no.: 1992-I0000-37036. Report date: 1992-03-11.
PFA, 2013u, Peter Fisk Associates, Analogue report - mammalian toxicity of linear and branched siloxanes, PFA.300.002.008
Respiratory sensitisation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Justification for classification or non-classification
Based on the available information on the read across substance, octamethyltrisiloxane (CAS 107-51-7), no classification for skin sensitisation is required 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.
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