Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
19 April to 4 May 1990
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Proprietary study, methodology similar to OECD guidelines

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Qualifier:
according to
Guideline:
other: "Method of Testing Toxic Substances", Federal Register, Part 191 (1961)
GLP compliance:
not specified
Remarks:
no certificate/statement of compliance included in report
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Terephthalic acid, identification number 10820-97, was received 11 January 1989. The test material was a white powder, and was stored at room temperature (~22°C).The purity was 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
Sex:
male/female
Details on test animals and environmental conditions:
Male and female New Zealand albino rabbits, approximately 2 months of age, purchased from Johnson Rabbit Ranch (Wilkinson, IN). The rabbits weighed 1.6-2.4 kg on arrival, and were acclimatised for approximately 4 weeks during which time they were examined to ensure their health and suitability as test subjects. Selected rabbits were identified by metal ear tags and corresponding cage cards.Each rabbit was provided with approximately 150 g of Purina Lab Rabbit Chow HF #5326 (Ralston Purina Co., MO) daily. Reverse osmosis-purified water was supplied ad libitum by means of an automatic watering system.The rabbits were housed individually in stainless steel cages. Poly pads were placed in the below the stainless steel mesh floor. The air-conditioned animal room was maintained at an average temperature and relative humidity of 23.7°C and 32%, respectively. Flurorescent lighting was provided on a 12 hour light/dark cycle.

Administration / exposure

Type of coverage:
occlusive
Vehicle:
water
Remarks:
test site pre-moistened with water
Details on dermal exposure:
The test article was applied undiluted. Individual doses were dispensed in glass vials.Approximately 24 hours prior to study initiation, the fur was clipped from an area of approximately 240 cm² on the back of each rabbit and the skin was examined for abnormalities. Care was taken to avoid abrading the animal's backs.The shaved application site was pre-moistened with water prior to application of the test substance. The test substance was covered with a 12.8 x 23.0 cm surgical dressing (Surgipad). The dressing was then covered by plastic film and secured by lint-free cloth and Elastoplast. The wrappings were removed after 24 hours and the skin was wiped gently with gauze and 0.9% saline to remove residual test article.
Duration of exposure:
24 hours
Doses:
2000 mg/kg bw.
No. of animals per sex per dose:
5 rabbits/sex
Control animals:
not required
Details on study design:
Rabbits used in the study were selected at random and assigned to a single group of 5 males and 5 females. Prior to selection, the rabbits received a thorough physical examination to ensure their suitability for use.All rabbits were observed aproximately 3/4, 3-1/4, 4-1/4 and 5-1/4 hours after dosing and at least once per day for 14 days after removal of the wrappings. All test animals were weighed immediately prior to dosing and the weights used for dosage calculations. The rabbits were weighed 7 days after application and at study termination.All rabbits were euthanised at the end of the observation period by anaesthetic overdose. A limited gross necropsy was performed on all test animals.
Statistics:
Formal statistical analysis was not required.

Results and discussion

Preliminary study:
A preliminary study was not conducted.
Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Remarks on result:
other: No mortality at the limit dose
Mortality:
No deaths occurred during the study.
Clinical signs:
Minor signs of dermal irritation (i.e. erythema) were observed within the appplication site of two male and four female rabbits immediately following unwrapping. The application site of all test animals was partially or completely masked by hair growth throughout the observation period.
Body weight:
The initial mean body weights of the male and female was rabbits were 2.59 and 2.45 kg, respectively. Mean body weights increased during the study.
Gross pathology:
No abnormalities were detected at necropsy.
Other findings:
No other findings were reported.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated informationCriteria used for interpretation of results: EU
Conclusions:
The acute dermal LD50 of terephthalic acid was found to be greater than 2000 mg/kg bw under the conditions of this study.
Executive summary:

The acute dermal toxicity of terephthalic acid was determined in a limit test, with five male and five female New Zealand White rabbits. The test material was placed in contact with the shaved pre-moistened skin of the rabbits, under an occlusive dressing, for 24 hours. The rabbits were observed during this time and for 14 days thereafter. No deaths occurred during the study. Mild dermal irritation (erythema) was observed within the application site of six rabbits immediately following unwrapping. Otherwise, no adverse treatment-related clinical signs were observed in any rabbits during the study. Mean body weights increased during the study. No gross pathological lesions attributable to treatment were evident in any of the rabbits at necropsy. The acute dermal LD50 of terephthalic acid was found to be greater than 2000 mg/kg bw under the conditions of this study.