Di-tert-butyl sec-butylidene diperoxide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study completion date: 20 August 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC (92/69/EEC, B.3, 31st July 1992)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Di-tert-butyl sec-butylidene diperoxide

EC Number:

218-507-2

EC Name:

Di-tert-butyl sec-butylidene diperoxide

Cas Number:

2167-23-9

Molecular formula:

C12H26O4

IUPAC Name:

2,2-bis(tert-butylperoxy)butane

additive 1

Reference substance name:

Hydrocarbons, C4, 1,3-butadiene-free, polymd., triisobutylene fraction, hydrogenated

EC Number:

297-629-8

EC Name:

Hydrocarbons, C4, 1,3-butadiene-free, polymd., triisobutylene fraction, hydrogenated

Cas Number:

93685-81-5

Molecular formula:

not applicable (a generic molecular formula cannot be provided for this specific UVCB substance)

IUPAC Name:

isododecane

Test material form:

liquid

Specific details on test material used for the study:

The test substance LUPEROX 220 M 50 used in the study was supplied by Elf Atochem S.A.
The test substance was identified as follows:
. name:
- protocol and labelling: 2,2-DI-(t-BUTYLPEROXY)BUTANE/LUPEROX 220 M 50
Both denominations correspond to the same test substance.
. batch number:
- protocol: 512-9800-001 (MXL)
- labelling: 512-9800-001 (XML)
. Elf Atochem filing number: CAL 1158/98
. description: colourless liquid
. container: one plastic flask
. date of receipt: 7 April 1998
. storage conditions: at room temperature and protected from light
. purity: 50.1 %
. expiry date: September 1998.
Data relating to the characterization of the test substance are documented in a test article description and an analytical certificate (presented in appendix 1) provided by the Sponsor.
The test substance received at CIT with the batch No. 512-9800-001 (MXL) corresponds to the substance LUPEROX 220 M 50, batch No. 512-9800-001 (MXL).
This was confirmed by the Study Monitor in a statement dated 14 August 1998.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals:
Species, strain: rat, Sprague-Dawley ICO: OFA-SD (IOPS Caw).
Reason for this choice: rodent species generally accepted by regulatory authorities for this type of study.
Breeder: Iffa Credo, 69210 L'Arbresle, France.
Number and sex: one group of ten animals (five males and five females).
Age/weight: on the day of treatment, the animals were approximately 8 weeks old, and had a
mean body weight± standard deviation of 266 ± 5 g for the males and 226 ± 8 g for the females.
Acclimatization: at least 5 days before the beginning of the study.
Identification of the animals: the animals were identified individually by earmarks or earnotches.

Environmental conditions:
During the acclimatization period and throughout the study, the conditions in the animal room were set as foilows:
. temperature: 21 ± 2°C
. relative humidity: 30 to 70%
. light/dark cycle: 12 h/12 h
. ventilation: approximately 12 cycles/hour of filtered, non-recycled air.
The temperature and relative humidity were under continuous control and recording. The records were checked daily and retained. In addition to these daily checks, the housing conditions and corresponding instrumentation and equipment are verified and calibrated at regular intervals.
During the acclimatization period, four to seven animals of the same sex were housed in polycarbonate cages ( 48 cm x 27 cm x 20 cm).
During the treatment period, the animals were housed individually in polycarbonate cages (35.5 cm x 23.5 cm x 19.3 cm).
Each cage contained dust-free sawdust (SICSA, 94142 Alfortville, France).
Bacteriological · and chemical analysis of the sawdust, including the detection of possible contaminants (pesticides, heavy metals), are performed regularly by external laboratories.
The results of these analyses are archived at CIT.

Food and water:
All the animals had free access to A04 C pelleted diet (UAR. 91360 Villemoisson-sur-Orge, France).
Each batch of food was analysed by the supplier for composition and contaminant levels.
Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum.
Bacteriological and chemical analysis of the water and diet, including the detection of possible contaminants (pesticides, heavy metals and nitrosamines), are performed regularly by external laboratories.
The results of these analyses are archived at CIT.
No contaminants are known to be present in the diet, drinking water or bedding material at levels which may be expected to interfere with or prejudice the outcome of the study.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Preparation of the animals:
On the day before treatment, the dorsal area (6 cm x 8 cm) of each animal was clipped using electric clippers. Only anima.ls with healthy intact skin were used for the study.

Administration of the test substance
The test substance was applied undiluted at the dose-volume of 2000 mg/kg, taking into consideration that its specific gravity was 0.81.
It was placed directly on an area of the skin representing approximately 10% (5 cm x 6 cm for the females and 5 cm x 7 cm for the males) of the body surface of the animals. This was calculated according to Meeh's formula. A hydrophilic gauze pad was then applied to the skin.
The test substance and the gauze pad were held in contact with the skin for 24 hours by means of an adhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage. This dressing prevented ingestion of the test substance by the animals.
No residual test substance was observed at removal of the dressing.
The dose applied to each animal was adjusted according to body weight determined on the day of treatment.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 males and 5 females per dose.

Control animals:

yes

Details on study design:

TREATMENT
As the test substance was anticipated to be non-toxic at 2000 mg/kg, a limit test was performed by application of 2000 mg/kg of the test substance to one group of ten animals (five males and five females).

CLINICAL EXAMINATIONS
Clinical signs and mortality
The animals were observed frequently during the hours following administration of the test substance, for detection of possible treatment-related clinical signs. Thereafter, observation of the animals was made at least once a day until day 15.
Type, time of onset and duration of clinical signs were recorded for each animal individually.
Time of death was recorded individually, in terms of the number of hours or days after dosing.

Body weight
The animals were weighed individually just before administration of the test substance on day 1 and then on days 8 and 15.
The body weight gain of the treated animals was compared to that of CIT control animals with the same initial body weight.

NECROPSY
On day 15, all animals were killed by carbon dioxide ·asphyxiation and a macroscopic examination was performed.
After opening the thoracic and abdominal cavities, a macroscopic examination of the main organs (digestive tract, heart, kidneys, liver, lungs, pancreas, spleen and any other organs with obvious abnormalities) was performed.
In case of macroscopic lesions, organ samples were taken and preserved in 10% buffered formalin.
No microscopic examination was performed.

Statistics:

DATA EVALUA TION
Evaluation of the toxicity of the test substance following a single dermal application in rats should include the relationship, if any, between the animals' exposure to the test substance and the incidence and severity of all abnormalities including behavioural and clinical abnormalities, macroscopic lesions, body weight changes, mortality and any other toxic effects.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No death occurred during the study.

Clinical signs:

No clinical signs and no cutaneous reactions were observed during the study.

Body weight:

The overall body weight gain of the animals was not influenced by treatment.

Gross pathology:

Macroscopic examination of the main organs of the animals revealed no apparent abnormalities.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under our experimental conditions, the dermal LD50 of the test substance LUPEROX 220 M 50 (batch No. 512-9800-001(MXL)) is higher than or equal to 2000 mg/kg in rats. No signs of toxicity were observed at this dose.

Executive summary:

SUMMARY

LUPEROX 220 M 50 (batch No. 512-9 800-00I( MXL)) was evaluated in rats according to OECD (No. 402. 24th February 1987) and EC (92/69/EEC, B.3, 31st July 1992) guidelines.

The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

Methods

The test substance was applied to the skin of one group of ten Sprague-Dawley rats (five males and five females).

The application was performed with the undiluted test substance at the dose of 2000 mg/kg, taking into consideration that its specific gravity was 0.81.

The test site was then covered by a semi-occlusive dressing for 24 hours .

Clinical signs mortality and body weight gain were checked for a period of 14 days following the single application of the test substance.

All animals were subjected to necropsy.

Results

No death occurred at 2000 mg/kg.

The general behaviour and overall body weight gain of the animals were not affected by treatment with the test substance.

No cutaneous reactions were observed.

No apparent abnorm alities were observed in all the animals at necropsy.

Conclusion

Under our experimental conditions, the dermal LD0 of the test substance LUPEROX 220 M 50 (batch No. 512-9800- 00I(M XL)) is higher than or equal to 2000 mg/kg in rats. No signs of toxicity were observed at this dose.