Reaction mass of Dicerium trisulfide and Dilanthanum trisulfide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

From 10 September 1996 to 28 April 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dicerium trisulphide

EC Number:

234-603-7

EC Name:

Dicerium trisulphide

Cas Number:

12014-93-6

Molecular formula:

Ce2S3

IUPAC Name:

Dicerium trisulphide

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Cerium sulphide

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan U.K. Ltd Bicester, Oxon, England.
- Age at study initiation: 8-10 weeks
- Weight at study initiation: 0.237-0.300 kg
- Fasting period before study: no data
- Housing: Rats were allocated without conscious bias to cages within the treatment groups. They were housed individually in metal cages with wire mesh floors in Building RI4 Room 6. Each animal was identified hy cage number and ear punching. Each cage was identified by a coloured label displaying the dose level, study schedule number, animal mark and the initials of the Study Director and Home Office licensee.
- Diet: standard laboratory rodent diet (SDS LAD 1) was provided ad libitum. Each batch of diet used for the study was analysed for certain nutrients, possible contaminants and micro-organisms.
- Water: ad libitum
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12 (0700-1900 hours)

IN-LIFE DATES: From: To: 14-28 October 1996

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

methylcellulose

Details on dermal exposure:

TEST SITE
- Area of exposure: 50 mm x 50 mm
- % coverage: 10
- Type of wrap if used: The test substance was applied by spreading it evenly over the prepared skin. Tne treatment area was covered with porous gauze held in place with a non irritating dressing, and further covered by a waterproof dressing encircled firmly around the trunk of the animal.

REMOVAL OF TEST SUBSTANCE
- Washing: with warm water (30° to 40°C) to remove any residual test substance. The treated area was blotted dry with absorbant paper.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2.16 ml/kg bodyweight corresponding to 2000 mg/kg bodyweight
- Concentration (if solution): 92.6 %
- Constant volume or concentration used: no data
- For solids, paste formed: no data

VEHICLE
- Concentration (if solution): 1% w/v aqueous methycellulose
- Lot/batch no. (if required): no data
- Purity: no data

Duration of exposure:

24 hours

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Preparation of the application site: One day prior to treatment, hair was removed from the dorso-lumbar region of each rat with electric clippers taking care to avoid damaging the skin, exposing an area of equivalent to approximately 10 % of the total body surface.
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Cages of rats were checked at least twice daily for any mortalities. Animals were observed soon after dosinng and at frequent intervals for the remainder of Day 1 (a period of approxirnately 4 hours). On subsequent days, animals were observed once in the morning and again at the end of the experimental day (with the exception of Day 15-morning only). This latter observation was at approximately 16.3 hours on week days or 11.3 hours on Saturdays and Sundays. The nature and severity of the clinical signs and time were recorded at each observation. All animals were observed for 14 days after dosing.
The body weights of each rat was recorded on Day 1 (prior to dosing), 8 and 15. Individual weekly bodyweight changes and group mean bodyweights were calculated.
Local dermal irritation at the treatment site was assessed daily using the numerical draize scoring system. Any other lesion not covered by this scoring system, was described.
-Termination: All animals were killed on day 15 by cervical dislocation.
- Necropsy of survivors performed: yes. All animals were subjected to a macroscopic examination which consisted of opening the abdominal and thoracic cavities. The macroscopic appearance of all tissues was reccorded and macroscopic abnormalities were preserved.

Statistics:

Not applicable

Results and discussion

Preliminary study:

Not applicable

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths following a single dermal dose of Dicerium trisulphide to a group of ten rats (five males and five females) at a dosage of 2000 mg/kg bodyweight.

Clinical signs:

other: There were no signs of systemic reaction to treatment

Gross pathology:

No macroscopic abnormalities were observed for the animals killed on Day 15.

Other findings:

Dermal responses: red staining on the dose site was noted immediately upon removal of the bandages on Day 2, persisiting through Day 8 in some animals. This was accompanied by slight erythema and slight edema in one male rat only. No other dermal response was seen in any of the test animals throughout the study.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The acute lethal dermal dose to rats of Dicerium trisulphide was shown to be greater than 2000 mg/kg bodyweight.

Executive summary:

This study was performed to assess the acute dermal toxicity of Dicerium trisulphide to the rat.

 

Methods

The method followed was that described in: the EEC Methods for the determination of toxicity, Annex to Directive 92/69/EEC (OJ No. L383A, 29.12.92), Part B, Method B.3. Acute toxicity (dermal).

 

A group of ten fasted rats (five males and five females) was given a single dose by topical application of the test substance administered at the maximum practical concentration of 92.6% in 1% w/v aqueous methylcellulose at a dose level of 2000 mg/kg bodyweight. All animals were killed and examined macroscopically on Day 15 (end of the observation period).

 

Results

There were no deaths and no signs of systemic reaction to treatment.

Red staining on the dose site was noted immediately upon removal of the bandages on Day 2, persisting through Day 8 in some animals. This was accompanied by slight erythema and slight edema in one male rat only. No other dermal response was seen in any of the test animals throughout the study.

Slightly low bodyweight gains were notable on Day 8 for four male and three female rats with a similar trend observed on Day 15 for four males and two females. All other rats achieved satisfactory bodyweight gains throughout the study.

No abnormalities recorded at the Day 15 following macroscopic examination.

 

Conclusion

The acute lethal dermal dose to rats of Dicerium trisulphide was found to be greater than 2000 mg/kg bodyweight.