Naphthenic acids

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: although no indication that it is a GLP study, sufficient detail is provided to make a conclusion about its validity.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference 1

Reference Type:

other: robust study summary

Title:

Unnamed

Year:

2003

Report date:

2003

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1979

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

This study is a combined study where Accute Dermal Toxicity is considered together with skin irritation.

Principles of method if other than guideline:

This study is a combined study where Accute Dermal Toxicity is considered together with skin irritation.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Naphthenic acids

EC Number:

215-662-8

EC Name:

Naphthenic acids

Cas Number:

1338-24-5

Molecular formula:

For the acidic (naphthenic) fraction: CnH2n+zO2, where n = carbon number and z = homologous group series number: z = 0 when no ring structures are present, z = -2 when 1 ring is present, z = -4 when 2 rings are present etc. For the non-acidic fraction: not applicable

IUPAC Name:

11-(decahydronaphthalen-2-yl)undecanoic acid; 11-cyclopentylundecanoic acid; 15-cyclohexylpentadecanoic acid; 3-(tetradecahydroanthracen-2-yl)propanoic acid; 4-(tetradecahydroanthracen-2-yl)butanoic acid; 7-(tetradecahydroanthracen-2-yl)heptanoic acid; 9-(octahydropentalen-2-yl)nonanoic acid; dodecahydro-1H-phenalene-1-carboxylic acid

Test material form:

liquid

Details on test material:

Physical state: Viscous liquid
Appearance: Pale yellow to dark amber

Test animals

Species:

rabbit

Strain:

New Zealand White

Test system

Type of coverage:

occlusive

Preparation of test site:

abraded

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Duration of treatment / exposure:

24 hours

Observation period:

14 days
Dermal irritation was recorded at 24h, 3, 7, 10 and 14 days.

Number of animals:

2 per sex

Details on study design:

3.16 g/kg naphthenic acid was applied dermally to the clipped abraded abdomens of 2 female and 2 male New Zealand White Rabbits. The area was covered with gauze and secured by a thick plastic binder, which was removed atfter 24 hours, and the skin washed with water or corn oil.
Following the skin wash, animals were observed for mortality and toxic effects at 2 hr and 4 hr, and once daily thereafter. Body weights were recorded pretest and at termination. Dermal irritation was recorded at 24 hr, 3, 7, 10 and 14 days.
The rabbits were observed 1, 2, 4 and 6 hours after dosing and once daily for 14 days. Mortality, toxicity and pharmacological effects were recorded. Body weights were recorded pretest and in the survivors at 14 days. At 14 days the survivors were sacrificed. Animals were examined for gross pathology.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

1.69

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Other effects:

The initial response of the skin to the test material was slight. with Iittle difference in response between intact or abraded sites.

Any other information on results incl. tables

Table 1. Erythema scores

Animal	1 day	3 day	7 day	10 day	14 day
Number
1M	2	2	4	4	1
2M	1	2	4	4	1
3F	2	4	4	4	0
4F	2	3	4	4	0
Note: All animals showed signs of scar formation after 14 days.

Table 2. Edema scores

Animal	1 day	3 dav	7day	10 day	14 day
Number
1M	3	2	2	2	1
2M	2	3	2	2	0
3F	3	3	2	2	0
4F	3	3	2	2	0

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The material was judged to be moderately to severely irritating to the occluded skin.

Executive summary:

New Zealand white rabbits were dermally treated with 3.16 g/kg Naphthenic acids under occlusive dressing for 24 hours, afeter which the skin was washed with water or corn oil. The rabbits were observed 1, 2, 4 and 6 hours after dosing and once daily for 14 days. No deaths occurred at the 3.16 mg/kg dose level. Redness and irritation scores were recorded at 24 hr, 3, 7, 10 and 14 days post-washing. Mean values (24, 48 & 72 hours) for erythema and edema at the intact sites were 1.69 and 1.3 respectively. The initial response of the skin to the test material was slight, with little difference in response between intact or abraded sites. Erythema and edema were partly reversible after 14 days; all animals showed signs of scar formation after 14 days.