Registration Dossier

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: see 'Remark'
Remarks:
The study was conducted according to OECD guideline 402: "Acute Dermal Toxicity" and current Good Laboratory Practice Regulations for non-clinical laboratory studies as set forth by both the US FDA(21 CFR 58) and the US EPA (40 CFR 160 and 40 CFR 792), as well as in accordance with the OECD Principles of Good Laboratory Practice.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
yes
Remarks:
The guideline mentions limit dose of 2000mg/kg but in the study amended as 4000mg/kg body weight for limit dermal dose level.
Qualifier:
according to guideline
Guideline:
other: EEC, Directive 84/449/EEC. Annex V of the EEC Directive 67/548/EEC.
GLP compliance:
yes
Test type:
other: Limit test
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
Young adult rats of the Wistar strain (8 weeks old at study start, SPF-quality, randomly bred) were supplied by Charles River Wiga GmbH, Sulzfeld, PRG. Upon receipt, each animal was identified with an ear tag.

At least five days prior to dosing (acclimatization period) the animals were group housed, five per sex, in polycarbonate cages containing purified sawdust (Woody Clean supplied by Broekman Institute, Someren, The Netherlands) as bedding material. The animals had free access to tap-water (via automatic nozzles) and a standard pelleted laboratory animal diet (RMH-B, pellet diameter 10 mm, Hope Farms, Woerden, The Netherlands).

The animal room was air-conditioned, with the temperature maintained within the range of 17-20°C and the relative humidity maintained within the range of 50-70% during the study. The artificial light cycle was 12 hours light, 12 hours dark.

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
The test substance was dosed, as supplied and evenly spread on a surgical gauze (5x5 cm and 5x3.5 cm for males and females, respectively), to one group of rats comprising 5 males and 5 females. This was fixed, successively, to aluminium foil and flexible bandage (Coban, 3M, St. Paul, Minn., USA), with drops of vaseline. This patch was then applied to the clipped area of each animal and fixed with adhesive tape (Sleek, Smith and Nephew, Hull, U.K.).

The dose level was 4000 mglkg bodyweight and the dose volume was 4.82 ml/kg bodyweight (calculated as follows: dose level + specific gravity). The specific gravity used was 0.83 g/ml. After 24 hours of exposure, the semi-occlusive bandage was removed and the remaining test substance on the treated skin surface was gently removed with tissues moistened with tap-water.

The day of application of the test substance was considered as day 0.
Duration of exposure:
24h
Doses:
4000mg/kg
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
Clinical observations were performed on the day of dosing (approximately 0.10, 2 and 4 hours after dosing) and once daily thereafter for 14 days. Any signs of toxicity were recorded along with the time of onset and duration.

Individual bodyweights were measured weekly.

At the end of the study (day 14) all animals were anaesthetised by CO2/O2 inhalation, subsequently killed by CO2 and subjected to necropsy.

In addition, observations regarding changes of the treated skin surface were performed following bandage removal and on days 4, 7 and 14.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 4 000 mg/kg bw
Based on:
test mat.
Remarks on result:
other: 1/5 males died, 0/5 females died
Mortality:
One male died after having convulsions approximately 4 hours after dosing.
Clinical signs:
Lethargy, bloody nose and eye encrustation, piloerection and pallor of the skin were noted among the surviving animals on the first two days of the study. The only other abnormality seen was irritation of the left eye of one male on day 13.

Small scabs were noted on the treated skin surface of one female on day 4. No other abnormalities were seen.
Body weight:
All surviving animals showed bodyweight gain between days 0 and 14. Males gained 48 ± 9.5 g (n=4) and females gained 19 ± 5.9 g (n=5), mean ± SD, over the period of the study.
Gross pathology:
Apart from an extra small spherical piece of liver on the median liver lobe of one female, no abnormalities were seen on macroscopic examination at necropsy of surviving animals at the end of the study.

Applicant's summary and conclusion

Conclusions:
The dermal LD50 value for males and females was noted as exceeding 4000 mg/kg body weight.