Dibenzylbenzene, ar-methyl derivative

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

Analytical concentrations are lacking, two different batch numbers are reported.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

The temperature measured at the end of the experiment was 26°C, above the recommended limit of 25°C; only one concentration was tested; there was no monitoring of the test atmosphere: test concentration, particle size and oxygen level not measured

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dibenzylbenzene, ar-methyl derivative

EC Number:

258-649-2

EC Name:

Dibenzylbenzene, ar-methyl derivative

Cas Number:

53585-53-8

Molecular formula:

C21H20

IUPAC Name:

dibenzylbenzene, ar-methyl derivative

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: IFFA CREDO, France
- Age at study initiation: not reported
- Weight at study initiation: 180-192 g (mean: 184,5g)
- Fasting period study: not reported
- Housing: 5/sex/cage
- Diet (e.g. ad libitum): sourifarrat 18%, ad libitum except during exposure
- Water (e.g. ad libitum): ad libitum except during exposure
- Acclimatation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +/- 20
- Air changes (per hr): 8
- Photoperiod (hrs dark /hrs light): 12/12

IN-LIFE DATES: not reported

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE/CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel cage
- Exposure chamber volume: 350 x 240 x 200 mm (100 L)
- Method of holding animals in test chamber: 5/sex/cage
- Source and rate of air: pure air passed through a debimeter, the rate was 1000 L/h
- Method of conditioning air: not indicated
- System of generating particulates/aerosols: pure air passed through a debimeter, then in a 500-mL erlenmeyer containg 350 mL of the substance, heated at 70°C by thermo-shaking, and then delivered to the exposure chamber
- Method of particle size determination: particle size not determined
- Treatment of exhaust air: not reported
- Temperature, humidity, pressure in air chamber:
beginning: 22°C and 45% humidity
end: 27°C and 53% humidity
- air changes (per hr): 10

TEST ATMOSPHERE
- Brief description of analytical method used: theoretical nominal concentration calculated by the ratio between the weight of substance per time unit (determined by the difference in the weight of the erlenmeyer) and air volume that passed into the exposure chamber during this time unit.
- Samples taken from breathing zone: no


VEHICLE: air
- Theoretical concentration of test material in vehicle (if applicable): 0.24 mg/L


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: not determined
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): not determined

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

0.24 mg/l

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: daily observation and weighing on days 1, 2, 4, 7 and 14
- Necropsy of survivors performed: yes

Statistics:

Not applicable

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 0.24 mg/L air

Exp. duration:

4 h

Mortality:

No mortality was observed.

Clinical signs:

other: - During exposure: after an initial agitation, sedation occurred (10 minutes after the start of exposure). After 30 minutes, eyes were closed but reactivity to noise was normal. Afterwards, behaviours were normal.- After exposure: normal behaviour

Body weight:

No effect was observed on the body weight.

Gross pathology:

No abnormalities were observed at the necropsy.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

No mortality was found at the dose level of 0.24 mg/L. In the absence of data at higher concentrations, the substance should be classified as toxic,
however a supporting study with dibenzyltoluene heated at 700°C (Ineris, 1993) indicated that LC0 was higher than 15,8 mg/L and thus the
substance was not classified for acute inhalation.

Executive summary:

The acute inhalation toxicity of Dibenzylbenzene, ar-methyl derivativewas evaluated in a 4-hour, single-exposure study in rats at the concentration of 0.24 mg/L, according to a protocol study close to OECD Guideline 403 (May 12th1981) with acceptable restrictions. 

Mortality, clinical observations for clinical signs and body weight changes were evaluated over a 14-day observation period.All animals were subjected to a gross necropsy.

 

No mortality was observed. During the exposure, initial agitation was first observed before sedation occurred (10 minutes after the start of exposure). After 30 minutes, eyes were closed but reactivity to noise was normal. Afterwards and until the end of the observation period, behaviours were normal. No abnormalities were observed at necropsy.