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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From April 23, 1982 to April 27, 1982
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted similar to EPA OPP 81-5, in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report date:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
EPA OPP 81-5 (Acute Dermal Irritation)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Methyl carbamate
EC Number:
209-939-2
EC Name:
Methyl carbamate
Cas Number:
598-55-0
Molecular formula:
C2H5NO2
IUPAC Name:
methyl carbamate
Test material form:
other: solid

Test animals

Species:
rabbit
Strain:
other: Albino New Zealand White
Details on test animals or test system and environmental conditions:
- Source: Sgarlett Breeders, Harvey's Lake, Pennsylvania
- Weight at study initiation: 2 - 3 Kg
- Housing: Rabbits were housed individually in cages sized in accordance with the "Guide for the care and use of laboratory animals" of the institute of laboratory resources, National research council.
- Diet: Wayne rabbit ration, ad libitum
- Water: Fresh tap water, ad libitum
- Acclimatization period: 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C±3°C
- Humidity (%): 30 to 70%
- Photoperiod: 12 h dark and 12 h light

Test system

Type of coverage:
occlusive
Preparation of test site:
clipped
Vehicle:
physiological saline
Amount / concentration applied:
Test substance
- Amount applied: 0.5 g (slightly moistened with 0.9% NaCl solution)
Duration of treatment / exposure:
24 h
Observation period:
24 h, 72 h and day 4 post application
Number of animals:
3/sex/dose
Details on study design:
Method and study performance:

Each of six adult albino rabbits of the New Zealand White strain were administered the test substance at four skin sites (two abraded and two intact sites). All application sites were clipped free of hair. The skin was abraded using a 21 gauge burred needle; the abrasion penetrated the stratum corneum but not the derma. Following the application of the test substance, one-inch square gauze patches were applied to each of the four sites and the trunk of the animal was wrapped with a rubber dam and an ace bandage to retard evaporation and the test substance was kept in contact with the skin site for 24 h. At the end of the 24 h exposure period, the wrappings were removed and the skin wiped (but not washed) to remove any test substance still remaining. Animals were observed and signs of erythema and edema were scored according to the Draize scale at 24, 72 h and day 4 post application.

Observations:
Animals were observed and signs of erythema and edema were scored according to the Draize scale at 24, 72 h and day 4 post application.
Body Weight: Day of treatment and at termination.
Irritation: The skin reactions were assessed at 24, 72 h and day 4 post dose.

Dermal Observations
Erythema and Eschar Formation (Most severely affected area graded)

No erythema ................................................................................................... 0
Very slight erythema (barely perceptible) ...................................................1
Well-defined erythema ....................................................................................2
Moderate to severe erythema ........................................................................3
Severe erythema (beet redness) to
slight eschar formation (injuries in depth) .................................................................. 4

Edema Formation (Most severely affected area graded):
No oedema ........................................................................................................ 0
Very slight oedema (barely perceptible) ....................................................... 1
Slight oedema (edges of area well-defined by definite raising) ................ 2
Moderate oedema (raised approximately 1 mm) ......................................... 3
Severe oedema (raised more than 1 mm and extending beyond the area of exposure)...4

Primary Irritation Index:
Mean values (6 animals) are calculated and summed as follows:
Erythema and eschar formation
Intact skin - 24 and 72 h - 2 values
Abraded skin - 24 and 72 h - 2 values
Edema formation
Intact skin - 24 and 72 h - 2 values
Abraded skin - 24 and 72 h - 2 values
TOTAL 8 values
Sum of mean values/4 = Primary Irritation Index

Results and discussion

In vivo

Results
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24 and 72 h
Score:
0.53
Max. score:
2
Reversibility:
fully reversible
Remarks on result:
other: The skin irritation had resolved within 72 h after exposure in four animals and within 4 d after exposure in the remaining animal.
Irritant / corrosive response data:
Irritation:
24 h exposure to 0.5 g of test substance resulted in very slight erythema in two animals and very slight oedema (barely perceptible) in all the animals at 24 h post application observation. The skin irritation had resolved within 72 h after exposure in four animals and within 4 d after exposure the remaining animal.

Colouration / remnants:
Based upon the observations made in the primary dermal irritation study in rabbits, test substance was considered to be a mild dermal irritant. (Draize Score = 0.53).
Other effects:
Body weight:
No changes were noted in the body weight of animals.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The substance was considered to be mild irritating to the skin.
Executive summary:

A study was conducted to assess the skin irritation potential of methyl carbamate in rabbits similar to EPA OPP 81-5, in compliance with GLP. A total of 0.5 g of the test substance slightly moistened with 0.9% NaCl solution was applied onto the clipped four skin sites (two abraded and two intact sites) of six animals for 24 h using a occlusive dressing. After exposure for 24 h, the wrappings were removed and the skin wiped (but not washed) to remove any test substance still remaining. Animals were observed and signs of erythema and edema were scored according to the Draize scale at 24, 72 h and day 4 post application. Exposure to test substance resulted in very slight erythema in two animals and very slight oedema (barely perceptible) in all the animals at 24 h post application. The skin irritation had resolved within 72 h after exposure in four animals and within 4 d after exposure the remaining animal.Based on the 24 and 72 h readings, the primary irritation index was calculated to be 0.53. Under the study conditions, the test substance was considered to be mild irritating to the skin (Mallory VT, 1982).