Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1973
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was conducted in accordance with a recognized scientific procedure for analyzing the acute inhalation toxicity of a test material in experimental animals. However, only males were tested and no gross pathology results were reported.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1973
Report date:
1973

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
yes
Remarks:
only one sex used (males), few data are provided on exposure conditions.
Principles of method if other than guideline:
Federal Hazardous Substances Act, Chapter II, Title 16 CFR
GLP compliance:
no
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Dibenzoyl peroxide
EC Number:
202-327-6
EC Name:
Dibenzoyl peroxide
Cas Number:
94-36-0
Molecular formula:
C14H10O4
IUPAC Name:
benzoyl benzenecarboperoxoate
Details on test material:
Purity = 78 percent; white granules (remainder water).

Test animals

Species:
rat
Strain:
other: Spartan albino
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 232-248 g
- Housing: by groups of 5 animals, in metal cages
- Food and water were available ad libitum pre- and post-exposure

ENVIRONMENTAL CONDITIONS
- Temperature and humidity were controlled quarters throughout the pre-exposure and post-exposure periods

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
A single group of 10 male rats were placed in a sealed 59.1 liter glass chamber and exposed for 4 hours to a dynamic atmosphere of test material.
Analytical verification of test atmosphere concentrations:
no
Remarks:
Concentrations were calculated
Duration of exposure:
4 h
Concentrations:
24.3 mg/l (the physical properties of the test material prohibited exposure of the test rats to highest atmospheric concentrations).
No. of animals per sex per dose:
10 males
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days (then the rats were sacrified)
- Frequency of observations and weighing: during the expsoure period, the rats were observed continuously for changes in behavior and/or appearance
- Necropsy of rats who died during or after the exposure: yes
- Necropsy of survivors performed: no
Statistics:
not applicable

Results and discussion

Preliminary study:
not applicable
Effect levels
Sex:
male
Dose descriptor:
LC0
Effect level:
24.3 mg/L air
Exp. duration:
4 h
Remarks on result:
other: no mortality
Mortality:
No mortality was observed at a single dose of 24.3 mg/L.
Clinical signs:
other:
Body weight:
Body weight gain was determined to be normal throughout study.
Gross pathology:
not performed (none of the animals died during and after the exposure)
Other findings:
No more data

Applicant's summary and conclusion

Interpretation of results:
study cannot be used for classification
Remarks:
Migrated information
Conclusions:
No mortality occured at a concentration of 24.3 mg/L of dibenzoyl peroxid (no highest concentration could be tested, limitations from the physical properties of the substance).
Executive summary:

The acute inhalation toxicity of dibenzoyl peroxide was evaluated in a 4-hour, single-exposure study in rats according to a method similar to the OECD Guideline 403 (May 12th1981). A limit test was performed: dibenzoyl peroxide was administered to a single group of ten male rats (Spartan strain) via whole-body vapor exposure at concentrations of 24.3 mg/L during 4 hours.

Mortality, clinical observations for clinical signs and body weight changes were evaluated over a 14-day observation period. Detailed clinical observations were conducted immediately following each exposure at 1 day, 2 days, and 5 days post-exposure.

No mortality occured during the exposure and during the post-exposure period.

During the exposure period, eye squint, dyspnea, salivation, lacrimation, erythema, increased and decreased respiratory rates, and increased and decreased motor activity were observed. After 24 hours post-exposure, all rats appeared normal. Observable signs after 48 hours post-exposure were soft stools. All animals appeared normal from day 5 until the end of the study. A few of the rats showed signs of ocular irritation (corneal opacity, ulceration of corneal surface)

Based on the results of this results, LD50 is expected to be more than 24.3 mg/L in rats, Spartan strain following a whole-body exposure to dust during 4 hours.