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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study, GLP-compliant, available as unpublished report, no restrictions, adequate for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1981
Report date:
1981

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Reference substance name:
Terphenyl
EC Number:
247-477-3
EC Name:
Terphenyl
Cas Number:
26140-60-3
Molecular formula:
C18H14
IUPAC Name:
1,1':4',1''-terphenyl
Constituent 2
Reference substance name:
MCS-1980
IUPAC Name:
MCS-1980
Details on test material:
- Name of test material (as cited in study report): MCS 1980 (or Santowax CST)
- Molecular formula (if other than submission substance): C18H14 and C24H18
- Molecular weight (if other than submission substance): 230 and 306
- Physical state: brown solid
- Lot/batch No.: QET 1303369

Test animals

Species:
rabbit
Strain:
New Zealand White
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Isaac's Farm, Litchfield, Illinois
- Age at study initiation: approximately 10 weeks (young adults)
- Weight at study initiation: 2.42 - 2.80 kilograms
- Housing: individually housed
- Diet (e.g. ad libitum): ad libitum. Purina Rabbit Chow (Registered Trademark of the Ralston-Purina Company, St. Louis, Missouri) will be used.
- Water (e.g. ad libitum): ad libitum. Water will be furnished by the City of St. Louis, Missouri.
- Acclimation period: at least five days

Administration / exposure

Type of coverage:
occlusive
Vehicle:
physiological saline
Details on dermal exposure:
TEST SITE
- Area of exposure: the dorsal surface
- % coverage: 10-30% of total body surface
- Type of wrap if used: The test material was held in place by means of an occlusive wrap of latex rubber secured by bandaging and elastic tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The excess material was wiped from the animal.
- Time after start of exposure: The occlusive wrap was removed after approximately 24 hours
Duration of exposure:
24 hours
Doses:
5000 mg/kg
No. of animals per sex per dose:
5 animals per dose per sex
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations for death and overt signs of toxicity were made three times during the first eight hours following test material administration and twice daily (morning and afternoon) thereafter. Body weights were recorded on days 0 (day of dosing), 7, and 14.
- Necropsy of survivors performed: yes
Statistics:
The acute dermal LD50 for each sex and for the combined sexes was calculated using the method of Finney [Finney, D.J., (1971). Probit Analysis (3rd edition). Cambridge University Press].

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Sex:
female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Sex:
male
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Mortality:
No deaths were observed in animals of either sex.
Clinical signs:
All clinical abnormalities observed during this study were considered to result from direct contact between the test material and the skin in the exposed area. Erythema of the skin occurred in nine animals. The duration of this effect ranged from two to thirteen days in individual, affected animals. Edema of the skin was observed in one female and two male animals on the first day after test material administration. Areas of inhibited growth of fur occurred in one female and two male animals and were observed on the last three days of the study.
Gross pathology:
At necropsy, most of the findings reflected the effect of direct contact of the skin in the exposed area with the test material. Redness of the skin was observed in two male and three female animals. Areas of inhibited fur growth occurred in one male and two female rabbits. Hardened skin was observed in one male animal. Raised skin occurred in one female animal. One animal of each sex had defatted skin. Both kidneys of one male animal had pitted exteriors, but this was not considered to represent toxicity of the test material.

Any other information on results incl. tables

Acute Dermal Toxicity to Rabbits Mean Body Weight and Mortality Summary

Dosage (mg/kg)

Mean body weight (Kg)

N° deaths / N° dosed

Days of death postdosing

Day 0

Day 7

Day 14

Male rats

5000

2.58

2.78

3.00

0/5

-

Female rats

5000

2.62

2.78

3.03

0/5

-

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute dermal LD50 for MCS-1980 was determined to be above 5000 mg/kg bw.
Executive summary:

No deaths followed a dermal application of 5000 mg/kg bw of MCS-1980 to the shaved and abraed dorsal surface of albino of both sexes. Therefore, the acute dermal LD50 of this material is considered to be in excess of 5000 mg/kg. Clinical abnormalities included erythema, edema, and inhibited growth of fur in the exposed area.