2-isopropyl-N,2,3-trimethylbutyramide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: U.S.A. Code of Federal Regulations, Title 16, Section 1500.41

Version / remarks:

the procedure employed was that prescribed by the Consumer Product Safety Commission of the U.S.A. Code of Federal Regulations, Title 16, Section 1500.41

Principles of method if other than guideline:

- Principle of test: Primary irritation to the skin is measured by a patch-test technique on the abraded and intact skin of the albino rabbit, clipped free of hair.

- Short description of test conditions: Six rabbits are used in abraded and intact skin tests. Introduce under a square patch, such as surgical gauze measuring 1 inch by 1 inch and two single layers thick, 0.5 milliliter (in the case of liquids) or 0.5 gram (in the case of solids and semisolids) of the test substance. Dissolve solids in an appropriate solvent and apply the solution as for liquids. The animals are immobilized with patches secured in place by adhesive tape. The entire trunk of the animal is then wrapped with an impervious material, such as rubberized cloth, for the 24-hour period of exposure. This material aids in maintaining the test patches in position and retards the evaporation of volatile substances. After 24 hours of exposure, the patches are removed and the resulting reactions are evaluated on the basis of the designated values.

- Parameters analysed / observed: erythema and eschar formation, oedema formation

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

2-isopropyl-N,2,3-trimethylbutyramide

EC Number:

256-974-4

EC Name:

2-isopropyl-N,2,3-trimethylbutyramide

Cas Number:

51115-67-4

Molecular formula:

C10H21NO

IUPAC Name:

2-isopropyl-N,2,3-trimethylbutyramide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- test material: WS 23, 0.1 % solution in 1% ethyl alcohol.

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- albino rabbits

Test system

Type of coverage:

other: patch-test technique

Preparation of test site:

other: the abraded and intact skin of the albino rabbit, clipped free of hair

Vehicle:

other: ethyl alcohol

Remarks:

1%

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- WS23, 0.1% solution in 1% ethyl alcohol.

VEHICLE
-no information available

NEGATIVE CONTROL
-no information available

POSITIVE CONTROL
- no information available

Duration of treatment / exposure:

24 hours

Observation period:

24 and 72 hours

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: a square patch, such as surgical gauze measuring 1 inch by 1 inch and two single layers thick, 0.5 milliliter of the test substance.
- % coverage: 100% (the entire trunk of the animal is wrapped)
- Type of wrap if used: an impervious material, such as rubberized cloth, for the 24-hour period of exposure.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not specified

OBSERVATION TIME POINTS
- 24 and 72 hours

SCORING SYSTEM:
- Method of calculation: GRADING OF SKIN REACTIONS (according to Code of Federal Regulations, Title 16, Section 1500.41. and OECD TG 404).
The "value" recorded for each reading (24 and 72 hours) is the average value of the six animals subject to this test.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

other: mean of animals

Time point:

24 h

Score:

ca. 0

Max. score:

0

Reversibility:

other: no indication of irritation

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

overall irritation score

Basis:

other: mean of animals

Time point:

72 h

Score:

ca. 0

Max. score:

0

Reversibility:

other: no indication of irritation

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

edema score

Basis:

other: mean of animals

Time point:

24/48/72 h

Score:

ca. 0

Remarks on result:

other: no edema observed

Remarks:

only 24 and 72 hours reading

Results 4

Irritation parameter:

erythema score

Basis:

other: mean of animals

Time point:

24/48/72 h

Score:

ca. 0

Remarks on result:

other: no erythema observed

Remarks:

only 24 and 72 hours reading

Any other information on results incl. tables

GRADING OF SKIN REACTIONS (according to Code of Federal Regulations, Title 16, Section 1500.41. and OECD TG 404):

Evaluation of skin reactions Erythema and eschar formation	value
No erythema	0
Very slight erythema (barely perceptible)	1
Well defined erythema	2
Moderate to severe erythema	3
Severe erythema (beef redness) to slight eschar information (injures in depth)	4

Evaluation of skin reactions Oedema formation	value
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 area of exposure)	4

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008

Remarks:

EU criteria used for interpretation of results

Conclusions:

WS-23 as a 0.1% solution in 1% ethyl alcohol is not considered to be an irritant to rabbit skin.

Executive summary:

In this key study, performed according to the procedure employed by the Consumer Product Safety Commission of the U.S.A., US Code of Federal Regulations, Title 16, Section 1500.41, the primary irritation to the skin was measured by a patch test technique in six albino rabbits.

The obtained results of the reading were also evaluated in accordance to the OECD TG 404.

 

WS-23 (0.1% solution in 1% ethanol) was applied to one intact and one abraded skin site on the clipped dorsum of rabbits.

After 24 hours of exposure, the patches were removed and the skin reactions, i.e. erythema and eschar formation as well as edema formation,

were evaluated.

 

None of the treated animals showed any observable response throughout the 72 hours observation period.

 

It was concluded based on the results, that WS-23 as a 0.1% solution in 1% ethyl alcohol was not an irritant to rabbit skin.