tert-butyl α,α-dimethylbenzyl peroxide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl α,α-dimethylbenzyl peroxide

EC Number:

222-389-8

EC Name:

tert-butyl α,α-dimethylbenzyl peroxide

Cas Number:

3457-61-2

Molecular formula:

C13H20O2

IUPAC Name:

[2-(tert-butylperoxy)propan-2-yl]benzene

Test material form:

liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

The weight of the males ranged from 186-192g, that of the females from 136-144g.
The rats were obtained from the Central Institute for the Breeding of Laboratory Animais, TNO, Zeist, The Netherlands.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: horizontally placed glass cylinder (0.90 x 0.15m) with sampling ports on both ends
- Exposure chamber volume: 0.135m3
- Method of holding animals in test chamber: stainless steel wire screens for the individual accommodation of the experimental animals.
- Source and rate of air: compresse air Iine, 1.0 L/min/evaporator
- Method of conditioning air: filtered air (relative humidity about 45%)
- System of generating vapors: 5 evaporator were laden with Chromosorb W-AW-60/80, saturated with Trigonox T. The temperature of the evaporators during the experiment was 22°C.
- Method of particle size determination: not relevant
- Treatment of exhaust air: no data
- Temperature in air chamber: 24°C

TEST ATMOSPHERE
- Brief description of analytical method used: Analysis of the peroxide was carried out gaschromatographically, using an "Intersmat" gas chromatograph with a FID (flame ionisation detector} and a stainless steel column (diemeter 6x 4mm; 0.30m) packed with QF-1 (14.8% diglycerol 0.13% on chromosorb G.AW-DMCS). Column -, injection- and detector-temperatures were 80, 95 and 100°C respectively. The gas-chromatograph was calibrated by injecting samples of a known solution of Trigonox T in ethanol.
- Samples taken from breathing zone: no

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Analysis of the peroxide was carried out gaschromatographically,

Duration of exposure:

4 h

Concentrations:

140 ppm (1.2 mg/L)

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

After exposure, the animals were returned to their living cages and provided with stock diet and tap water ad libitum for an observation period of 14 days.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 1.2 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occured.

Clinical signs:

other: Eye irritation and a decreased respiration frequency were observed. During the first quarter of an hour of the exposure period, the rats were slightly restless and kept their eyes half-closed. For the remainder of the exposure period the rats were rather

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

From the results of the present acute inhalation study it is concluded that the 4-hour LC0 of Terbutyl cumyl peroxide is higher than 140ppm (1.2mg/l).

Executive summary:

The acute inhalation toxicity of Trigonox T (90 -92 % w/w of tert-butyl a,a-dimethylbenzyl peroxide) was studied by exposing rats for four hours to an atmosphere containing 140 ppm of the test material, which was the highest concentration attainable. No mortality occurred. Eye irritatioin and a decreased respiration frequency were observed. The 4-hour LC0 of Trigonox T in rats appeared to be higher than 140 ppm (1.2 mg/L).