Di-tert-butyl sec-butylidene diperoxide

Endpoint summary

Description of key information

The oral LD50 is > 30 ml per kg body weight. The relative density of di-tert-butyl sec-butylidene diperoxide, 50% solution in isododecane at 20°C is 0.8114. Therefore, the LD 50, as administered, is 24.34 g/kg bw.

The inhalation LC50 is higher than 2.42 g/m3 air.

The dermal LD50 is >= 2000 mg/kg bw.

From these results, the substance is not classified for acute toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Date: 14 June 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

fixed dose procedure

GLP compliance:

not specified

Test type:

fixed dose procedure

Specific details on test material used for the study:

A 1kg sample of the test material was received from the principal on April 9, 1979. It was a clear colourless liquid, designated Trigonox D-E50, and coded nr. 5478090039. The material was stated to be a 50% solution of 2,2 di-tert-butyl-peroxybutane in mineral oil.

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Young adult albino rats (Wistar derived) from the Institute's colony were used. The body weights of males varied from 185 to 263 g, those of females from 103 to 142 g. The rats were housed in groups of five screen-bottomed stainless steel cages, in a well-ventilated room, maintained at 23±1°C. Before dosing the rats were fasted overnight.

Route of administration:

oral: gavage

Vehicle:

not specified

Remarks:

mineral oil

Details on oral exposure:

After some preliminary observations, the test material was given undiluted by gavage to groups of ten males and ten females in one single dose of 30.0 ml per kg body weight. This dose is considered to be the highest tolerable amount to be given in a single dose.

Doses:

30.0 ml per kg body weight

No. of animals per sex per dose:

10 males and 10 females per dose.

Control animals:

no

Details on study design:

After treatment, the rats received stock diet and water ad libitum. The were observed for signs of intoxication during a 14-day period, after which autopsies were carried out on the survivors.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 30 mL/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

Within a few hours after treatment the rats showed sluggishness humpback behaviour and severe diarrhoea. Later on the rats recovered gradually and looked quite healthy again at the end of the observation period.

Gross pathology:

Macroscopic examination of the survivors at autopsy did not reveal any treatment-related gross alterations.

Interpretation of results:

GHS criteria not met

Conclusions:

From the results, it appears that the LD50 of Trigonox D-E50 exceeds 30 ml per kg bodyweight. Therefore, the material can be classified as relatively harmless.

Executive summary:

From the results, it appears that the LD₅₀ of Trigonox D-E50 exceeds 30 ml per kg bodyweight (24.34 g/kg bw, based on density, 0.8114).

Therefore, the material can be classified as relatively harmless.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start of the study: 9 May 1979 End of the study: 14 June 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Principles of method if other than guideline:

Trigonox D-B50 was dispersed to a fine mist by means of a stainless steel/glass aerodynamic nozzle nebulizer. The nebulizer was provided with a baffle in order to remove the larger droplets from
the mist produced. The mist was passed through the exposure chamber with a total airflow of 1.6 m^3/h for Trigonox D-B 50.

GLP compliance:

no

Test type:

traditional method

Limit test:

yes

Specific details on test material used for the study:

Samples of the test materials were received from the principal on 9 April 1979. Trigonox D-B50 is also a clear, colourless liquid with the following composition:
49-51 % 2.2 -Di-tert-butylperoxy butane
51-49 % Dibutyl phthalate

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Fifty male and fifty female SPF-reared rats (Cpb; WU, Wistar Random) were obtained from the Central Institute for the Breeding of Laboratory Animals TNO, Zeist, The Netherlands. At the beginning of the study the mean body weight of the males was 180 g and that of the females 135 g.
During the 2-week observation period foll owing the exposure the animals were kept in stainless steel cages (5 to a cage), which were suspended in an open rack in an animal room. They received ad libitum the Institute's stock diet for rats and bottled unfluoridated water. However, during exposure the animals had no access to water and food.
The temperature and the relative humidity in the animal room were 21±1°C and 50 - 60 per cent respectively; they were automatically controlled.

Exposure chamber:
A stainless steel exposure chamber, having a capacity of 1.5 m^3 was used. The rats were kept individually during the exposure in wire-screen cages to prevent crowding and minimize filtration of inspired air by the animals' fur. They could be continuously observed through the hard glass entrance door of the chamber.

Route of administration:

inhalation: mist

Type of inhalation exposure:

not specified

Vehicle:

air

Details on inhalation exposure:

Trigonox D-B 50 was dispersed to a fine mist by means of a stainless steel/glass aerodynamic nozzle nebulizer. The nebulizer was provided with a baffle in order to remove the larger droplets from
the mist produced. The mist was passed through the exposure chamber with a total airflow of 1.6 m^3/h for Trigonox D-B 50.

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

4 h

Concentrations:

The maximum attainable concentration of the Trigonox D-B 50 aerosol in the test atmosphere turned out to be 2.42 g/m^3 air.

No. of animals per sex per dose:

5 animals per sex per dose.

Control animals:

no

Details on study design:

Analysis:
Analysis of the test atmosphere of Trigonox D-B 50 was performed gravimetrically. Samples of the atmosphere was taken by passing a measured quantity of the test atmosphere through a Cambridge glassfibre filter at intervals of about 1.5 hour. Particle size determinations and counts were carried out in samples taken from the atmosphere in the chamber with a Cascade Impactor.

Conduct of the study:
Five males and five females were exposed to the test material for 4 hours. After the exposure period the animals were returned to their living cages for an observation period of 2 weeks. During the 2-week observation period the body weight of the animals was frequently recorded.

Calculation of the LC50-values:
If applicable, the four-hour LC50 was calculated according to the method of Litchfield and Wilcoxon (1949).

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

2.42 other: g/m^3 air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred during the 4-hour exposure period and the subsequent observation period of 14 days.

Body weight:

The males and females gained weight in a normal way during the 14-day observation period.

The maximum attainable concentration of the Trigonox D-B 50 aerosol in the test atmosphere turned out to be 2.42 g/m³ air.

Droplet size determinations in impaction samples revealed a maximum droplet diameter of 6.7 μm. Ninety per cent of the mist consisted o.f droplets with a diameter of 1.2-3.3 μm.

No information on the behaviour of the rats during the exposure is available, because the animals were completely invisible as a consequence of the dense mist prevailing in the inhalation chamber. No mortality occurred during the 4-hour exposure period and the subsequent observation period of 14 days.

The males and females gained weight in a normal way during the 14-day observation period.

Interpretation of results:

GHS criteria not met

Conclusions:

From the results of the present acute inhalation toxicity studies it is concluded that:
the 4-hour LC50 of Trigonox D-B 50 in rats is higher than 2.42 g/m^3 air.

Executive summary:

1. The acute inhalation toxicity of curing agent, Trigonox D-B 50, was studied separately by exposing rats one single time for 4 hours to atmospheres containing aerosols

of each of the various substances.

2. Exposure to Trigonox D-B 50 at the maximum attainable concentration of 2.42 g/m³ air did not result in mortality or any sign of intoxication. It was concluded that the

4-hour LC₅₀ of Trigonox D-B 50 in rats was higher than 2.42 g/m³ air.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Link to relevant study records

Reference

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

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

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.

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.

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.

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.

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Justification for classification or non-classification

The oral LD50 is > 30 ml per kg body weight (= 24.34 g/kg bw).

The inhalation LC50 is higher than 2.42 g/m3 air.

The dermal LD50 is >= 2000 mg/kg bw.

From these results, the substance is not classified for acute toxicity.