2-isopropyl-N,2,3-trimethylbutyramide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

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. Code of Federal Regulation, Title 16, Section 1500.42

Version / remarks:

The Consumer Product Safety Commission of the U.S.A.

Principles of method if other than guideline:

- Principle of test: test for eye irritants

- Short description of test conditions:
Animal facilities for such procedures shall be so designed and maintained as to exclude sawdust, wood chips, or other extraneous materials that might produce eye irritation. Both eyes of each animal in the test group shall be examined before testing, and only those animals without eye defects or irritation shall be used. The test material is placed in one eye of each animal by gently pulling the lower lid away from the eyeball to form a cup into which the test substance is dropped. The lids are then gently held together for one second and the animal is released. The other eye, remaining untreated, serves as a control.

- Parameters analysed / observed:
An animal shall be considered as exhibiting a positive reaction if the test substance produces at any of the readings ulceration of the cornea (other than a fine stippling), or opacity of the cornea (other than a slight dulling of the normal lustre), or inflammation of the iris (other than a slight deepening of the folds
(or rugae) or a slight circumcorneal injection of the blood vessels), or if such substance produces in the conjunctive (excluding the cornea and iris) an obvious swelling with partial eversion of the lids or a diffuse crimson-red with individual vessels not easily discemible.

The eyes are examined and the grade of ocular reaction is recorded at 24, 48 and 72 hours. Reading of reaction is facilitated by use of a binocular loupe, hand slit-lamp, or other expert means.

The test shall be considered positive, if four or more of the animals in the test group exhibit a positive reaction. If only one animal exhibits a positive reaction, the test shall be regarded as negative. If two or three animals exhibit a positive reaction, the test is repeated using a different group of six animals.
The second test shall be considered positive if three or more of the animals exhibit a positive reaction. If only one or two animals in the second test exhibit a positive reaction, the test shall be repeated with a different group of six animals. Should a third test be needed, the substance will be regarded as an irritant if any animal exhibits a positive response.

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

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- test material: WS-23

Test animals / tissue source

Species:

rabbit

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source:albino rabbits

Test system

Vehicle:

other: 1% ethyl alcohol

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL
- Concentration (if solution): 0.1%

VEHICLE
- Concentration (if solution): 1% ethanol

Duration of treatment / exposure:

7 days

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

6 animals

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: not

SCORING SYSTEM: grades from ocular lesion From: "Illustrated Guide for Grading Eye Irritation by Hazardous Substances" U.S. Department of Health, Education and Welfare, Food and Drug Administration Washington, D. C. 20204

TOOL USED TO ASSESS SCORE: hand-slit lamp, binocular loupe

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

7 d

Score:

> 0 - <= 2

Max. score:

2

Reversibility:

fully reversible within: 7 days

Remarks on result:

other: not irritating

Results 2

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

1

Reversibility:

fully reversible within:

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

conjunctivae score

Remarks:

redness and chemosis

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

2

Reversibility:

fully reversible within: 7

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 0

Remarks on result:

no indication of irritation

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 gave a negative response for eye irritation.

Executive summary:

In this study, 0.1  mL of the  test item, WS-23 (0. 1%  solution  in 1 % of ethyl  alcohol), was applied  into one eye of each animal. In total 6 rabbits were used in this testing. The lids of animals were gently held together  for approximately one second.  The other eye,  remaining untreated,  serves as a control. WS-23 was not washed from the eye during the observation period of 7 days.

One animal gave a positive reaction. A diffuse crimson red colouration of  the  conjunctivae  was observed  in this animal  two days after instillation. Temporary  mild  conjunctival  inflammation  was  observed  in  four other  animals.  One  animal  did not show any  observable  response  to the treatment  throughout  the 7 days observation  period.

 

Based on these results, it was concluded that WS 23 (0.1% solution  in 1%  ethyl  alcohol) gave  a negative response for eye  irritation, according to the definition given  in  the Code of Federal  Regulations as well as according to OECD TG 405.