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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation / corrosion, other
Remarks:
In vivo done previously
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16 March 1990 - 20 April 1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study protocol was not in accordance with modern guidelines, which for example would have required fewer animals, but the scientific basis of the method followed is nevertheless robust.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report):
- Substance type: Complex reaction product.
- Physical state: Liquid.
- Analytical purity: Assumed to be 100% for the purpose of dosing.
- Impurities (identity and concentrations): NA.
- Composition of test material, percentage of components: The study report does not contain information on test material characterisation or analysis; it confirms this information is held by the study sponsor Exxon Chemical Company, Paramins Division (now Infineum).
- Lot/batch No.: I.
- Expiration date of the lot/batch: NDA.
- Stability under test conditions: NDA.
- Storage condition of test material: Room temperature.
- Other: pH = 4. A 10% (v/v) mixture of test material in reverse osmosis water was prepared by adding 18 mL water to 2 mL test material. The test material.water mixture was shaken by hand in a closed jar and the pH was measured by immersing a ColopHast pH 0-14 pH paper strip.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton Research Products, Denver, PA.
- Age at study initiation: Approximately 11 weeks.
- Weight at study initiation: Approximately 2-3 kg.
- Housing: Individually housed in suspended steel cages.
- Diet (e.g. ad libitum): Restricted feeding regimen.
- Water (e.g. ad libitum): Ad libitum.
- Acclimation period: 15 days.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 65-70ºF (18.3-21.1ºC).
- Humidity (%): Target himudity range was 40-60%. Measured humidity exceeded 60% once during the acclimation period and twice during the study; however, the study authors concluded that these deviations did not adversely affect the study results.
- Air changes (per hr): NDA.
- Photoperiod (hrs dark / hrs light): 12 hours light / 12 hours dark.


IN-LIFE DATES: From: 20 March 1990 To: 27 March 1990

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 mL
Duration of treatment / exposure:
4 hours
Observation period:
7 days
Number of animals:
6
Details on study design:
TEST SITE
- Area of exposure: Not stated.
- % coverage: Not stated.
- Type of wrap if used: The test material was introduced under a gauze patch which was secured with tape. The patch was loosely held in contact with the skin by means of a semi-occlusive dressing.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test material was removed, where possible, using reverse osmosis water and paper towels.
- Time after start of exposure: Four hours.


SCORING SYSTEM: Dermal responses were scored according to the Draize method (see below).

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Time point:
72 h
Score:
0.89
Reversibility:
fully reversible within: 7 days
Irritation parameter:
edema score
Basis:
mean
Time point:
72 h
Score:
0
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Score:
0.92
Other effects:
There were no supplemental dermal observations noted during the study.

Any other information on results incl. tables

Mean erythema and oedema scores at each time interval

35 min

24 hour

48 hour

72 hour

7 day

Erythema

1.00

0.83

0.83

1.00

0.00

Oedema

0.00

0.00

0.00

0.00

0.00

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the findings and the primary irritation index of 0.92, the test material may be considered a mild irritant to rabbit skin.
Executive summary:

The dermal irritancy potential of the test material was tested in a GLP study in rabbits. 0.5 mL of neat liquid test material was applied under a gauze patch to the shaved dorsal skin of six male New Zealand White rabbits and held in place using a semi-occlusive dressing. After approximately four hours of exposure, the dressing and gauze patch were removed, residual test material washed away using water and paper towels, and the dermal responses scored periodically over the next seven days according to the Draize method.

Erythema responses of 0 (no erythema), 1 (very slight erythema - barely perceptible), or 2 (well-defined erythema) was seen in all animals during the initial 72 hours post-administration. The mean erythema score for the 24 -, 48- and 72 -hour observations was 0.89. By Day 7, there was no erythema in any animal. No oedema was observed at any time and no supplemental dermal observations were noted. A primary dermal irritation index (PII) of 0.92 was calculated. Based on the findings and the PII, the test material may be considered a mild irritant to rabbit skin.