1-isocyanatooctadecane 1-isocyanatohexadecane

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: study meets generally accepted scientific principles; but limited documentation

Data source

Reference

Reference Type:

other: microfiche

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-5 (Acute Dermal Irritation)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Octadecyl isocyanate

EC Number:

204-019-7

EC Name:

Octadecyl isocyanate

Cas Number:

112-96-9

Molecular formula:

C19H37NO

IUPAC Name:

1-isocyanatooctadecane

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Ace Animals
- Housing: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least one week

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

Amount(s) applied: 0.5 ml/test site (2.0 ml/animal)

Duration of treatment / exposure:

4 hours

Observation period:

4, 24 and 72 hours, 7 and 14 days after application

Number of animals:

6

Details on study design:

The test article was heated gently to melt and dosed by volume, 0.5 ml/site, for a total dose of 2.0 ml/rabbit. The test article was applied to four intact sites on the back of each animal and were covered with 2.5 cm square gauze patches which were secured with adhesive tape. The torso was loosely wrapped with plastic which was secured with adhesive tape. The sites were occluded for 4 hours, at which time the patches and occlusive bindings were removed. The sites were wiped with a paper towel to remove excess test article. Erythema and edema were scored according to the numerical Draize technique. Additional signs were described. The general health of the animals was monitored at each observation time.

Results and discussion

In vivo

Results

Irritation parameter:

other: modified primary irritation index

Basis:

animal: # 1, 2, 3, 4, 5, 6

Time point:

other: 4, 24, 72 hours

Score:

1.93

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Any other information on results incl. tables

Erythema and edema were absent at 4 and 24 hours but increased significantly by 72 hours. Erythema was well defined to moderate at 72 hours and on days 7 and 14. In addition, the reactions were generalized over a large area of the skin of the animals. Instances of epidermal cracking and fissuring, poor hair regrowth and areas of shiny skin were also noted. Edema was well defined to severe by 72 hours and was also generalised over a large area of the skin. In some instances the edema extended beyond the exposed site but was not raised greatly. Yellow nasal discharge was noted in one animal at 24 and 72 hours. There were no abnormal systemic signs noted in the remaining five animals.

Applicant's summary and conclusion

Executive summary:

In a dermal irritation study according to EPA OPP 81-5 octadecyl isocyanate was applied under occlusive dressings for 4 hours to the shaved skin of 6 rabbits. Skin irritation was assessed after 4, 24, 72 hours and 7 and 14 days using the Draize scale. The modified primary irritation index was 1.93 of max. 4. According to EPA criteria, the test article is considered to be Category IV (mild or slight irritation). However, the reactions noted at 72 hours and on days 7 and 14 indicate that octadecyl isocyanate can produce delayed skin reactions of a severe nature.