N,N-dimethylacetamide

Skin irritation / corrosion

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

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

Test material information

Constituent 1

Reference substance name:

N,N-dimethylacetamide

EC Number:

204-826-4

EC Name:

N,N-dimethylacetamide

Cas Number:

127-19-5

Molecular formula:

C4H9NO

IUPAC Name:

N,N-dimethylacetamide

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 or test system 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

Results 1

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Reversibility:

other: no data for a 3rd animal

Remarks on result:

other: no data for a 3rd animal

Results 2

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Reversibility:

other: no data for a 3rd animal

Remarks on result:

other: no data for a 3rd animal

Results 3

Irritation parameter:

erythema score

Remarks:

20 h exposure

Basis:

animal #1

Time point:

other: mean 24h/72h

Score:

1

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: no data after 48 h; fine scales at the end of observation period

Results 4

Irritation parameter:

erythema score

Remarks:

20 h exposure

Basis:

animal #2

Time point:

other: mean 24h/72h

Score:

1

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: no data after 48 h

Results 5

Irritation parameter:

edema score

Remarks:

20 h exposure

Basis:

animal #1

Time point:

other: mean 24h/72h

Score:

0

Max. score:

4

Reversibility:

other: no abnormality detected

Remarks on result:

other: no data after 48 h

Results 6

Irritation parameter:

edema score

Remarks:

20 h exposure

Basis:

animal #2

Time point:

other: 24h/72h

Score:

0

Max. score:

4

Reversibility:

other: no abnormality detected

Remarks on result:

other: no data after 48 h

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 (no abnormality detected).

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.