Methanone, 1,1'-(1,4-phenylene)bis[1-(4-fluorophenyl)-

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2005-11-11 - 2005-12-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline comparable study; restriction: no data on control animals

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2005

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Bis(4-fluorophenyl) ketone

EC Number:

206-466-3

EC Name:

Bis(4-fluorophenyl) ketone

Cas Number:

345-92-6

IUPAC Name:

bis(4-fluorophenyl)methanone

Constituent 2

Reference substance name:

4,4'-Difluorobenzophenone

IUPAC Name:

4,4'-Difluorobenzophenone

Details on test material:

bis(4-fluorophenyl) ketone, purity 99 % ;
phaysical state: white powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ORGANISMS: 
- Source: Animals Raising Lab. of Shanghai B.K. company; licence number SCXK(hu) 2003-0002
- Weight at study initiation: males 205 - 222 g, females 187 - 194 g
- Diet: ad libitum
- Water: ad libitum
- Temperature (°C): 20 °C +/- 3° C
- Humidity (%): 55 % +/- 15 %
- Illumination: natural lights
- Number of animals: 5 per concentration and sex

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

- Exposure method: dynamic inhalation method
Mean chamber temperatur: 20 +/- 2°C;
Dust airflow rate: 10 L/min;
Sampling flow rate: 1.0 L/min;
Sampling volume: 5.0 L/per time;
Sampling frequency: one time/30 min;
Exposure duration: 4 hours

Ten rats (5 males and 5 females) were exposed to each concentration of the test material aerosol. Each rat was restrained in a single transparent polycrylic tube with adjustable unit. The exposure tubes were accomplished in the portholes of the inhalation chamber, and then the later was airproofed. The dust was generated from dust generation system and injected continouusly to the chamber with a dust injector at the top of chamber. The exhaust air was removed from the outlet at the bottom of the chamber to absorbing set. After exposure the animals were returned to their living cages, provided with diet and water ad libitum and observed for 2 weeks.

- Particle size analysis:
The particle sizes of test material were measured with the microscopic micro-marker method;
Result: < 5.0 µm 68%; 5.0 - 10 µm 31%

- Aerial concentration analysis:
The concentrations in the chamber were measured with a dust sampler in the following procedure. The sampler head was introduced into the chamber. The dust was collected with 2 layers of filter film (aperature 0f 0.1 µm) and weighted, and the concentration was calculated.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

single dose: 5050 mg/m3

No. of animals per sex per dose:

5 males and 5 females

Control animals:

not specified

Details on study design:

- Post dose observation period: 14 days
- Observation of clinical signs:
Following exposure, the individual animal was observed at every hour until 6 hour after administration, at least twice daily thereafter in forenoon and afternoon. Individual body weights were recorded in 3, 7, and 14 days after exposure. Clinical symptoms and numbers of dead rats were recorded. The surviving animals were euthanized and examined for gross pathological changes.
- Disposal of Spare animals:
Spare animals were euthanized after observation period and the remain were burned with a specially designed furnace.

Statistics:

The estimation of the acute inhalation toxicity (LC50) for bis(4-fluorophenyl) ketone to rats was done using probit method.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 050 mg/m³ air

Exp. duration:

4 h

Remarks on result:

other: No deaths occurred

Mortality:

No deaths occurred.

Clinical signs:

other: After being exposed, all rats showed toxic signs such as nasal discharge, semi-closed eyelid. After 72 hours, the toxic signs disappeared and all the rats were in normal conditions.

Body weight:

Except of a few rats, all surviving males and females treated showed increase in body weight during the test.

Gross pathology:

No apparent changes were found in necropsy.

Other findings:

No other treatment related effects were observed within this study.

Any other information on results incl. tables

no further information

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

The LC50 (inhalation, aerosol, 4 hrs) value in rats (male, female) was estimated to be > 5050 mg/m3. Therefore, under the conditions of this study the acute toxicity of the test substance after inhalation exposure is very low .

Executive summary:

The acute inhalation toxicity study of bis(4-fluorophenyl) ketone was conducted in male and female Sprague-Dawley rats. A single dose concentration of 5050 mg/m3 was selected for both sexes. Animals were exposed to the test substance for 4 hours and subsequently observed for clinical signs of toxicity and mortality for 14 days after dosing. No deaths were occurred. All rats showed toxic signs such as nasal discharge and semi-closed eyelid. After 72 hours, the toxic signs disappeared and all the rats were in normal conditions.

The LC₅₀ (inhalation, aerosol, 4 hrs) value in rats (male, female) was estimated to be > 5050 mg/m³.