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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): N-METHYLACETAMIDE, 98/392-1
- Physical state: Colorless solid
- Analytical purity: 99.82% (GC)
- Lot/batch No.: Tank 143
- Date of manufacturing: September 24, 1998
- Stability: Reanalysis: stable until January 1999.
- Storage condition of test material: at room temperature (approx. 20°C) away from direct
sunlight.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Elevage Scientifique des Dombes F-0 1400 Chatillon sur Chalaronne
- Number of animals: 1 male, 2 females
- Age at study initiation: 15 weeks
- Weight at study initiation: male: 2.589 kg, females: 2.702 and 2.853 kg
- Housing: Individually in stainless steel cages with an automatic cleaning system equipped with feed hoppers, drinking water bowls, with haysticks and wood for gnawing.
- Diet (e.g. ad libitum): Pelleted standard Kliba 3410 rabbit maintenance diet ad libitum (batch no. 62/98). Provimi Kliba AG, 4303 Kaiseraugst, Switzerland.
- Water (e.g. ad libitum): Community tap water from Itingen, ad libitum, provided by water bowls.
- Acclimatization period: 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ±3
- Humidity (%): 40-70
- Air changes (per hr): 10-15 air changes per hour,
- Photoperiod (hrs dark / hrs light): 12 hour Iight/dark cycle.


Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
Ihe test article is a solid at room temperature. To liquify the test article, it was warmed in a waterbath to approximately 40°C, and allowed to cool slightly for application.
- Amount(s) applied (volume or weight with unit): 0.5 ml to each rabbit.
- Concentration (if solution): undiluted.


Duration of treatment / exposure:
4 h
Observation period:
3 days
Number of animals:
3
Details on study design:
TEST SITE
- Area of exposure: the test article was applied to approximately 6 cm2 of the intact skin of the clipped area. lt was covered with a 2.5 cm x 2.5 cm patch of surgical gauze and the gauze was covered with a semi-occlusive dressing. Ihe dressing was wrapped around the abdomen and anchored with tape.
- Type of wrap if used: 3 days before treatment, the dorsal fur was clipped with an electric clipper, exposing an area of approximately 100 cm2 (10 cm x 10 cm). The skin of the animals was examined approximately 24 hours before treatment, and, if necessary, regrown fur was again clipped.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the skin was flushed with lukewarm tap water to clean the application site so that any reactions (erythema) were clearly visible at that time.
- Time after start of exposure: 4 h

SCORING SYSTEM: The skin reaction was assessed according to the numerical scoring system listed in the EEC Commission Directive 92/69/EEC, July 31, 1992 at approximately 1, 24, 48 and 72 hours after the removal of the dressing, gauze patch and test article.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
4
Reversibility:
other: no effects
Irritation parameter:
edema score
Basis:
mean
Time point:
other: 24, 48, 72 h
Score:
0
Max. score:
4
Reversibility:
other: no effects

Applicant's summary and conclusion

Interpretation of results:
not irritating