1,1-dimethylprop-3-ynylamine

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Not reported

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Incomplete reporting on materials and methods with an insufficient level of detail on results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1969

Report date:

1969

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

(abraded skin being used in addition to intact skin.)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,1-dimethylprop-3-ynylamine

EC Number:

221-029-7

EC Name:

1,1-dimethylprop-3-ynylamine

Cas Number:

2978-58-7

Molecular formula:

C5H9N

IUPAC Name:

2-methylbut-3-yn-2-amine

Details on test material:

30D11
Appearance: clear, colourless liquid with a pungent odour.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: adult
- Diet (e.g. ad libitum): Purina Rabbit Cow ad libitum
- Water (e.g. ad libitum): ad libitum

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5 mL.

Duration of treatment / exposure:

A single application covered for 24 hours.

Observation period:

72 hours.

Number of animals:

3 animals (intact skin); 3 animals (abraded skin)

Details on study design:

Administration: A single application of 0.5 mL of the liquid material was made under one-inch square patches to closely clipped, intact (three animals) or abraded (three animals) skin areas on the back of each of the animals.
Following application, the trunk of each animal was wrapped with a rubber dam binder. Each animal was immobilized in a multiple animal restrainer for an exposure period of 24 hours. After 24 hours, the patches were removed, and the skin was evaluated for irritation.
Observations and Records: All animals observed for primary skin irritation at 24, 48, and 72 hours after application. Irritation was graded and scored according to Draize (see below).


Local dermal irritation was assessed using the prescribed numerical system:

Erythema and eschar formation:

No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) or eschar formation (injuries in depth) preventing erythema reading 4

Oedema formation:

No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of area well-defined by definite raising) 2
Moderate oedema (edges raised approximately 1 millimetre) 3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure) 4


The "value" recorded for each reading is the average value of the six or more animals subject to the test.

The values for erythema and eschar formation at 24 hours and 72 hours for intact skin animals will be added to the values on abraded skin animals at 24 and 72 hours (four values). Similarly, the values for oedema formation at 24 hours and at 72 hours for the intact and abraded skin animals will be added (four values). The primary irritant score is the total of the eight values divided by four. A primary irritant is one which results in a score of five or more as tested by this method.

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: mean for 24 and 72 hours

Score:

2.67

Remarks on result:

other: Index arbitrary because of blanching effect on abraded sites.

Irritant / corrosive response data:

Blanching on abraded skin indicated a corrosive effect which precluded precise determination of a primary irritation index.

Other effects:

Very slight (one intact site only) to severe erythema noted on abraded and intact sites from 24 hours through 72 hours and slight oedema at 24 hours on one intact site only. Blanching was noted on the abraded sites from 24 hours through 72 hours and dark brown areas observed on exposed sites of two abraded and one intact animal.

Any other information on results incl. tables

Primary Irritation Index: Values shown in Table 1 below represent the average values for erythema and oedema obtained. One animal died from undetermined causes 48 hours after exposure; therefore, the 24-hour scores were the average obtained from three abraded and three intact sites, and the 72-hour scores represent the average from two abraded and three intact sites.

Table 1

24 Hours		72 Hours		Primary Irritation Index
Abraded	Intact	Abraded	Intact
2.66	3.50	3.50	1.0	2.67*

*Index arbitrary because of blanching effect on abraded sites

Applicant's summary and conclusion

Interpretation of results:

Category 1C (corrosive)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Very slight (one contact site only) to severe erythema was noted on abraded and intact sites from 24 hours through 72 hours and slight edema at 24 hours on one contact site only. Blanching was noted on noted on the abraded sites from 24 hours through 72 hours and dark brown areas observed on exposed sites of two abraded abraded and one intact animal. The effects seen are indicative of corrosivity.

Executive summary:

Very slight (one contact site only) to severe erythema was noted on abraded and intact sites from 24 hours through 72 hours and slight edema at 24 hours on one contact site only. Blanching was noted on noted on the abraded sites from 24 hours through 72 hours and dark brown areas observed on exposed sites of two abraded abraded and one intact animal. The effects seen are indicative of corrosivity.