Di-tert-pentyl peroxide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 1a: GLP, OECD 402 Guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Di-tert-pentyl peroxide

EC Number:

234-042-8

EC Name:

Di-tert-pentyl peroxide

Cas Number:

10508-09-5

Molecular formula:

C10H22O2

IUPAC Name:

2-methyl-2-[(2-methylbutan-2-yl)peroxy]butane

Test material form:

liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, lnc., Portage, Michigan.
- Weight at study initiation:270-294 g (male) / 210-217 g (female)
- Housing: individually, individually in suspended stainless steel cages
- Food and water ad libitum
- Acclimation period: at least five days


ENVIRONMENTAL CONDITIONS
- Temperature: 52-74 °F
- Humidity (%): 52 to 76
- Air changes (per hr): 10-15 cycles/hour
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- % coverage: 10% of the total body surface of the animals
- Type of wrap if used: gauze pad held in contact with the skin by means of anadhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage

REMOVAL OF TEST SUBSTANCE
After an approximate 24-hour exposure period, the gauze dressing, plastic and elastic wrap were removed and the corners of the test site delineated using a marker. Residual test article was removed using gauze moistened with distilled water.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg

Duration of exposure:

24H

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
* Clinical signs and mortality twice daily on day 0 and then once daily
* Body weight measured just before administration then on days 0, 7 and 14
* Animals were examined for erythema and edema following patch removal on study day 1 and daily thereafter (days 2-14)
- Necropsy : All limit test animals were euthanized (carbon dioxide inhalation) at study termination (day 14) and necropsied. Body cavities (cranial, thoracic, abdominal and pelvic) were opened and examined. No tissues were retained.


The temperature and relative humidity of the animal room (62-74°F and 52-76%, respectively) exceeded the ranges specified in the protocol (61-73°F and 40-70%, respectively) during this study. These ocurrences are considered to have had no adverse effect on the outcome of this study.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality

Clinical signs:

other: The most notable clinical abnormalities observed during the study included urine stain and dark material around the facial area, which occurred during the 24 hour exposure period. Dermal irritation was noted at the site of test article application.

Gross pathology:

No gross pathology was found at necropsy.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under these experimental conditions, the dermal LD0 of di-tert-amyl peroxide is more than 2000 mg/kg in rats.

Executive summary:

The acute dermal toxicity of Di-tert-amyl peroxide was evaluated in rats according to a method similar to OECD 402 . The test item was applied to the skin of ten Sprague-Dawley rats (five males and five females) at the dose-level of 2000 mg/kg in semi-occlusive dressing for 24 hours. Animals were then observed during 14 days for mortality, clinical signs, effects on body weight and then necropsied. No mortality occurred during the limit test. The most notable clinical abnormalities observed during the study included urine stain and dark material around the facial area, which occurred during the 24 hour exposure period. Dermal irritation was noted at the site of test article application. Body weight loss was noted for two female rats during the study day 0-7 interval and for one female during the study day 7-14 interval. Body weight gain was noted for all other animals during the test period. No significant gross internal findings were observed at necropsy on study day 14. Under the experimental conditions, the dermal LD0 of the test item Di-tert-amyl peroxide is higher than 2000 mg/kg in male/female rats.