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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
Study period:
29 March to 29 June 1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Proprietary non-GLP study, conducted according to OECD guidelines

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
no
Remarks:
no certificate or statement of compliance included in report

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Terephthalic acid, identification no. 10820-97, described as a white powder and stored at room temperature (approximately 22°C).
Purity not stated. However, terephthalic acid is a monomer used in the production of saturated polyesters, and a purified (> 99.9% w/w) feedstock (free of production-process impurities) is essential for this purpose. The batch of terephthalic acid used in this study is considered to have been representative of commercial production and to have been at least 99% pure.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
The animals were New Zealand White rabbits of either sex, weighing approximately 2.0-3.5 kg on arrival. Rabbits were supplied by Johnson Rabbit Ranch, IN. The rabbits were acclimatised for at least 1 week prior to study initiation, during which time they were examined to ensure their health and suitability as test subjects,
Each rabbit was housed individually in a suspended stainless steel cage. Poly pads were placed in the pans below the mesh.
Approximately 150 g of Purina Lab Rabbit Chow HF #5326 (Ralston Purina Co., St. Louis, MO) was provided daily for each rabbit. Reverse osmosis purified water was available ad libitum.
Individuals were identified by metal ear tags and corresponding cage cards. Fluorescent lighting was provided on a 12 hour light/dark cycle.

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
yes, concurrent no treatment
Amount / concentration applied:
0.5 g undiluted test material was applied (doses were weighed onto aluminium foil).
Duration of treatment / exposure:
4 hours
Observation period:
72 hours after dressing removal
Number of animals:
Three
Details on study design:
Prior to study initiation, the backs of all candidate test animals were shaved and checked for abnormalities. Animals found at this stage to have significant skin abnormalities encompassing the entire shaved back were not included in the study.
Approximately 24 hours prior to testing, fur from the trunk of the animals was clipped so that no less than 10% (~240 cm²) of the dorsal body surface was available for application.
The treated site was covered by a 2.5x2.5 cm adhesive dressing (Coverlet, Beiersdorf). The entire midsection of each rabbit was then wrapped in a lint free cloth towel secured by Elastoplast. Each rabbit had a treated and an untreated test site, to provide a control for comparison.
All wrapping materials were removed 4 hours after application. Following unwrapping, the test sites were rinsed with approximately 2 ml of 0.9% saline and towel dried.

All rabbits were weighed immediately prior to application of the test material. All animals were observed for morbidity and mortality at least once daily following treatment. All test sites were examined for signs of dermal irritation (oedema, erythema and/or eschar formation) and corrosivity (ulceration and/or necrosis) 30-60 minutes, 24, 48 and 72 hours after removal of the wrappings. The skin reactions were graded according to the Draize method (Draize, 1959).

Results and discussion

In vivo

Results
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24, 48 and 72 hours
Score:
0.2
Reversibility:
fully reversible within: 72 hours
Irritant / corrosive response data:
No signs of dermal corrosivity were seen in any rabbit during the study. The irritation score ranged from 0.7/8.0 at 30-60 minutes, to 0.0/8.0 at 72 hours following unwrapping.
Other effects:
No other effects reported.

Any other information on results incl. tables

The irritation score ranged from 0.7/8.0 at 30-60 minutes, to 0.0/8.0 at 72 hours following unwrapping.

The Primary Dermal Irritation Score for terephthalic acid was 0.2.

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The Primary Dermal Irritation Score for Terephthalic Acid was 0.2. No signs of dermal corrosivity were seen in any rabbit during the study.
Executive summary:

Terephthalic acid was applied for 4 hours to the shaved backs of three rabbits at a dose of 0.5 g. Following unwrapping, the test sites were rinsed with saline. All test sites were examined for signs of irritation and corrosivity according to the Draize method at 30 -60 minutes, 24, 48 and 72 hours following removal of the wrappings. No signs of dermal corrosivity were seen in any rabbit during the study. The irritation score ranged from 0.7/8.0 at 30-60 minutes, to 0.0/8.0 at 72 hours following unwrapping. The Primary Dermal Irritation Score for Terephthalic Acid was 0.2. It can be concluded that terephthalic acid is not irritating to rabbit skin.