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Toxicological information

Skin irritation / corrosion

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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

Constituent 1
Chemical structure
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.