Fatty acids, C16-22

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Reliable without restriction, test procedure according to national standards (DIN, etc.). Tested with the source substance CAS 57-11-4. In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1974

Report date:

1974

Reference 2

Reference Type:

secondary source

Title:

Final report of the safety assessment for oleic acid, lauric acid, palmitic acid, myristic acid, stearic acid

Author:

CIR

Year:

1987

Bibliographic source:

JACT, 6(3): 321-401

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Patch test / Revised (1964) Federal Hazardous Substance Act

Deviations:

not specified

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Stearic acid

EC Number:

200-313-4

EC Name:

Stearic acid

Cas Number:

57-11-4

Molecular formula:

C18H36O2

IUPAC Name:

stearic acid

Details on test material:

- Analytical purity: no data given

Test animals

Species:

rabbit

Strain:

New Zealand White

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

24 hours

Observation period:

72 hours

Number of animals:

6

Details on study design:

Fur was removed from the back of each of six rabbits by clipping the saddle of the trunk area. One area of skin was abraded by making minor incisions with a hypodermic needle. 0.5 ml of test material was applied to 1 in2 gauze patches. The patches were placed on both intact skin and abraded skin of each rabbit and secured with adhesive tape, rubber dental damming secured with staples, and gauze wound loosely around the trunk. The animals were then immobilized for 24 hours in wooden stocks. After 24 hours, the patches were removed and the skin cleaned by gently sponging with a moistened towel. The skin was examined immediately after removal of the patches (24 hr reading) and again at 72 hrs. At each examination the skin was scored for presence and severity of erythema/eschar formation and edema formation.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

other:

Time point:

other: 24 hours

Score:

0

Max. score:

8

Reversibility:

other: not effects noted

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Scores were not determined at the 48-h reading time point, however since the erythema score was 0 at the 24-h and 72-h reading time point, the same was considered for the 48-h reading time point.

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Scores were not determined at the 48-h reading time point, however since the erythema score was 0 at the 24-h and 72-h reading time point, the same was considered for the 48-h reading time point.

Irritant / corrosive response data:

No signs of skin irritation were observed on intact or abraded sites at either scoring time point.

Any other information on results incl. tables

Material (0.5 ml) was applied via a one-inch-square surgical gauze patch to intact and abraded-skin sites. Patches were held in place for 24 hours. Reactions were scored immediately after patch removal and two days later (72 hours).

Scores for Skin Irritation

Rabbit No.		24 hrs	72 hrs
43	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0
44	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0
45	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0
46	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0
47	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0
48	Intact      Erythema-Eschar      Edema Abraded      Erythema-Eschar      Edema	0     0 0 0	0 0 0 0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU