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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
04.10.1993 to 12.10.1993
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Hexamethyldisilazane
- Physical state: liquid
No further details available

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton, Michigan, USA.
- Age at study initiation: No data
- Weight at study initiation: 2.98 - 3.09 kg
- Housing: Individually in conventional design stainless steel cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Seven days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Controlled, but no data
- Humidity (%): Controlled, but no data
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): Controlled, but no data


IN-LIFE DATES: From: 04.10.1993 to 12.10.1993

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
Duration of treatment / exposure:
4 hours
Observation period:
Seven days (1, 24, 48, 72 hours and 7 days)
Number of animals:
Three
Details on study design:
TEST SITE
- Area of exposure: Dorsal trunk
- % coverage: No data
- Type of wrap if used: The application site was covered with porous gauze dressing and then wrapped in a semi-occlusive fashion with a cotton bandage taped to the hair.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: four hours

SCORING SYSTEM: The 4 point scale cited in the OECD guideline (404) was used. 

Results and discussion

In vivo

Results
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24, 48 and 72 hours
Score:
1.22
Max. score:
8
Reversibility:
fully reversible within: Seven days
Irritant / corrosive response data:
No irritation was observed at the one-hour reading following the four hour exposure. Erythema was seen in two of the three animals following the four-hour exposure. Erythema was observed at 24, 48 and 72 hours in two rabbits.  All signs of irritation had subsided by the seventh day observation period. The third animal showed no signs of irritation during the study. 

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: OECD GHS
Conclusions:
In a skin irritation study (reliability score 1), conducted to OECD 404 and GLP, hexamethyldisilazane did not cause significant irritation and was not corrosive to the rabbit skin.

Classification: not irritating
Executive summary:

In a IUCLID 2008 summary of a skin irritation study (reliability score 4), conducted to OECD 404 and GLP, 0.5 ml undiluted hexamethyldisilazane was applied to one intact site of each animal (three New Zealand white rabbits), and the site was covered with porous gauze and then wrapped in a semi-occlusive cotton bandage.After a four hour exposure period the application site was washed with tap water. Skin reactions were scored at one, 24, 48 and 72 hours and seven days. No irritation was noted after one hour. Erythema was observed in 2/3 animals, at 24, 48 and 72 hours. All signs of irritation had reversed by day 7. The third animal showed no signs of irritation throughout the study. The primary dermal irritation score was calculated to be 1.22, and overall the conclusion was that the test substance was minimally irritating to the skin of rabbits.