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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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
-Purity: 96.8%

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Buckshire Corporation, Perkasie, Pennsylvania
- Age at study initiation: Young adult
- Weight at study initiation: 2390-2964 g
- Housing: The rabbits were housed singly in suspended, stainless steel, wire-mesh cages
- Diet (e.g. ad libitum): Purina Certified Rabbit Chow® #5322
- Water (e.g. ad libitum): No details are available on the source of the water
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C ± 2°C
- Humidity (%): 50% ± 10%
- Air changes (per hr): No information is available
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark cycle

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: Shaved and abraded on the left side and shaved and intact of the right side of the rabbit
Vehicle:
other: Dimethyl phthalate to moisten the test substance
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g moistened with dimethyl phthalate
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
1 male and 5 females
Details on study design:
TEST SITE
- Area of exposure: scapular to the lumbar region of the back
- Type of wrap if used: 1-inch gauze square that was held in place with non-irritating tape; Rubber sheeting was then wrapped around the animal and secured with clips to retard evaporation and to keep the test material in contact with the skin without undue pressure

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test sites were gently washed with paper towels and warm water to remove excess test material and gently wiped dry
- Time after start of exposure: 24 hours

OBSERVATION TIME POINTS
24, 48, and 72 hours following the application of the test material

SCORING SYSTEM:
- Method of calculation: The numerical values corresponding to each animal for erythema and edema were recorded at each observation period. Mean group scores were calculated for each dermal response (erythema and edema) by summing the scores obtained from all intact sites at the 24-, 48-, and 72-hour observations. The 3 means corresponding to the 3 observation periods were averaged and Overall Averages were obtained for each dermal lesion.

In addition, for each of 6 rabbits, the values for both dermal lesions at 24, 48, and 72 hours were summed and divided by 3 to obtain primary irritation scores. A Primary Irritation Index (P.I.I.) which is an average of these 6 scores was also calculated.

Results and discussion

In vivo

Results
Irritation parameter:
other: Primary Irritation Index (P.I.I.)
Basis:
other: All 6 animals
Time point:
24/48/72 h
Score:
0
Max. score:
5
Reversibility:
other: No irritation was observed; therefore reversibility is not an appropriate parameter
Remarks on result:
no indication of irritation
Irritant / corrosive response data:
No irritation was observed at any of the time points for observation.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Not irritating when applied to the intact and abraded, shaved skin of rabbits. Primary Irritation INdex (P.I.I.) score is 0 on a scale of 0 (No irritation) to 5 (Severe irritation).
Executive summary:

Approximately 0.5 g of the test substance, moistened with dimethyl phthalate, was applied to each site beneath a 1-inch gauze square that was held in place with non-irritating tape. The rubber sheeting was then wrapped around the animal and secured with clips to retard evaporation and to keep the test material in contact with the skin without undue pressure (OECD Guideline 404)

 

Approximately 24 hours after application of the test material, the rubber sheeting was loosened, and the skin at the corners of the gauze squares was marked with a waterproof pen; wrappings and gauze squares were then removed. The test sites were gently washed with paper towels and warm water to remove excess test material and gently wiped dry.

 

Approximately 24 hours after application of the test material, the test sites were evaluated for erythema, edema, and other evidence of dermal effects and were scored according to the Draize scale. Additional evaluations were made at 48 and 72 hours after removal of the patches. The adjacent areas of untreated skin were used for comparison.

 

Dermal erythema and edema are evaluated and scored at 24, 48, and 72 hours following the application of the test material at the end of the 24-hour exposure in each of 6 rabbits. The reversibility of any dermal effects is assessed for up to 14 days, if necessary. Dermal effects are quantified according to the Draize Scale.

 

Scores for the intact sites obtained at the 24-, 48-, and 72-hour observations are added together and a mean group score is calculated for each lesion at each of these 3 observation times. Classification of dermal irritancy potential according to the EEC is based on the mean scores for the lesions observed. An Overall Average of these 3 means is also calculated. When no dermal irritation is observed in any of the test sites, the P.I.I. is 0.

The P.I.I. score for the test substance was zero (0) and therefore the test substance is not a skin irritant when tested on the skin of rabbits.