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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:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study is comparable to OECD Guideline 404 with acceptable restrictions (partly limited documentation, e.g. no scoring 48 h after exposure; ca. 1 mL test substance applied, exposure period 20 h and occlusive coverage conditions [worst case scenario]).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1970
Report Date:
1970

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Principles of method if other than guideline:
Skin irritation was tested using an internal method (BASF test) which is similar to OECD 404.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
- Name of test material: dimethylacetamide (DMAC)
- Purity: 99.9 %
No further details available.

Test animals

Species:
rabbit
Strain:
Vienna White
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 2.35 kg (male), 2.63 kg (female)

No further details available.

Test system

Type of coverage:
occlusive
Preparation of test site:
other: no data (presumably shaved)
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount applied: approximately 1 mL

The application site (dorsal skin) was covered with a cotton patch of 2.5 x 2.5 cm; the patch was soaked with the test substance and applied to the skin; no further data.
Duration of treatment / exposure:
1, 5, or 15 minutes (washing with Lutrol or 50 % aqueous Lutrol) or 20 h (unwashed)
Observation period:
Results were recorded each working day for up to 7 days (exceptions: see Table 2). The first scoring was conducted 24 h after initiation.
Number of animals:
2 rabbits
Details on study design:
REMOVAL OF TEST SUBSTANCE
- Washing: After the reported exposure time the skin was washed (not after 20 h exposure).

SCORING SYSTEM:
BASF grading for redness and edema (see Table 1 below).

Results and discussion

In vivo

Results
Irritation parameter:
erythema score
Basis:
mean
Remarks:
of 2 animals
Time point:
other: 24-96 h
Score:
1
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: 20 h exposure period; no edema detected; fine scaling in one rabbit at day 7
Irritant / corrosive response data:
In the female rabbit no effects were detected after 1-15 minutes exposure except a slight reddening on the day of exposure, and concerning 15 minutes exposure a slight reddening also at the day after exposure; in the male rabbit also no effects were detected except a questionable reddening 1-3 days after exposure for 1-15 minutes.

Data after 20 h exposure are presented in the Table 2 below.
No edema was seen in any test animal. At all time points for scoring not more than a questionable reddening was detected, which was reversible after 7 days. One rabbit showed a fine scaling 7 days after application.
Other effects:
Body weight was not altered in both animals.
No further effects were reported.

Any other information on results incl. tables

Table 2: Skin erythema in 2 rabbits after dermal exposure to the undiluted test substance for 20 h

Time after initiation of exposure

20 hours exposure; erythema in

Rabbit 1 (f)

Rabbit 2 (m)

24 h

1

1

48 h

no data

no data

72 h

1

1

4 days

1

1

 7 days  fine scales  0

- Evaluation transformed to OECD-Draize scoring; no edema reported.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
DMAC was no skin irritant in rabbit. A slight transient (questionable) reddening of the skin was noted.
Executive summary:

In a study according to a BASF internal standard method comparable to OECD 404, two rabbits were dermally exposed to undiluted liquid test substance (ca. 1 mL) for 1, 5, 15 minutes or for 20 h to the back skin. The coverage was occlusive; the skin was washed after exposure (not after the exposure period of 20 h). Skin reaction was scored 24, 72, 96 h and 7 days after initiation.

The test substance had only slight skin irritant properties after an exposure period of 20 h. Questionable to slight reddening was found after 1-15 minutes of exposure, effects were reversible 48-96 h after exposure. After the 20 h exposure period no edema was seen in any test animal. At all time points for scoring not more than a questionable reddening (OECD score 1) was detected, which was reversible after 7 days. One rabbit showed a fine scaling 7 days after application. Therefore, the test substance was considered to be no skin irritant.