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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:
1999-11-09 to 2000-01-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
1992
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River UK Limited, Margate, Kent, England
- Age at study initiation: at least 6 weeks
- Weight at study initiation: less than 3.5 kg
- Housing: individually housed in labelled cages with perforated floor
- Diet: standar laboratory rabbit diet approx. 100 g per day
- Water: free access to tap-water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21 °C
- Humidity: 30-70 %
- Air changes: 15 air changes per hour
- Photoperiod: 12 hours artificial fluorescent light and 12 hours dark per day

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 mL

Duration of treatment / exposure:
4 hours
Observation period:
21 days
Number of animals:
3 animals of one sex
Details on study design:
TEST SITE
- Area of exposure: 2x3 cm
- Type of wrap if used: a metalline patch was mounted on Micropore tape, which was wrapped around the abdomen and secured with Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing: the dressing was removed and the skin cleane of residual test substance using water
- Time after start of exposure: four hours

SCORING SYSTEM: according to guideline

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: 24,48,72 hours
Score:
2.7
Max. score:
4
Reversibility:
fully reversible within: 21 days
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: 24, 48, 72 hours
Score:
3
Max. score:
4
Reversibility:
fully reversible within: 21 days
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: 24, 48, 72 hours
Score:
2.7
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 24, 48, 72 hours
Score:
2.8
Max. score:
4
Reversibility:
fully reversible within: 21 days
Irritation parameter:
edema score
Basis:
animal #1
Time point:
other: 24, 48, 72 hours
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: 24, 48, 72 hours
Score:
3
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritation parameter:
edema score
Basis:
animal #3
Time point:
other: 24, 48, 72 hours
Score:
2.7
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritation parameter:
edema score
Basis:
mean
Time point:
other: 24, 48, 72 hours
Score:
2.7
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritant / corrosive response data:
- Irritation:
Four hours exposure to 0.5 mL of the test item resulted in moderate to severe or severe erythema and moderate to severe oedema in the treated skin-areas of the three rabbits. The skin irritation had resolved within 14 days after exposure in one animal and within 21 days in the two remaining animals. Reduced flexibility and/or fissuring of the skin, scaliness and bald skin were noted among the animals between 48 hours and termination (after 14 or 21 days).

- Corrosion
There was no evidence of a corrosive effect on the skin.
Other effects:
- Colouration
On the skin of all animals, sticky remnants of the test substance were present on day 1 and dry remnants were present from day 2 onwards until day 4.

- Toxicity / Mortality
No symptoms of systemic toxicity were observed in the animals during the test period and no test substance related mortality occured.

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant) based on GHS criteria
Conclusions:
No evidence of full thickness destruction of the skin or scar tissue was observed during the observation period, indicating that no corrosion of the skin had occured by dermal application of the test substance to intact rabbit skin.
Executive summary:

Tert-butyl peroxyneodecanoate (75 % in solvent) was tested in a primary skin irritation/corrosion study in the rabbit (4 -hour semi-occlusive application) according to EU method B.4 and the OECD guideline no. 404. Three rabbits were exposed to 0.5 mL of the test item, applied onto clipped skin for 4 hours using a semi-occlusive dressing. Observations were made 1, 24, 48 and 72 hours and 7, 14 and/or 21 days after exposure.

Exposure to the test item resulted in moderate to severe erythema and moderate to severe oedema in the treated skin-areas of the three rabbits

with mean erythema score of 2.8 and mean edema score of 2.7. The skin irritation had resolved within 14 days after exposure in one animal and within 21 days in the two remaining animals. Reduced flexibility and/or fissuring of the skin, scaliness and bald skin were noted among the animals between 48 hours and termination (after 14 or 21 days). On the skin of all animals, sticky remnants of the test substance were present on day 1 and dry remnants were present from day 2 onwards until day 4.

No evidence of full thickness destruction of the skin or scar tissue was observed during the observation period, indicating that no corrosion of the skin had occured by dermal application of the test substance to intact rabbit skin.