Teflubenzuron

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 October 1983 to 17 October 1983

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

1981

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP statement dates to Dec 18, 1987 QA statement dates to Nov 21, 1983

Test type:

traditional method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea

EC Number:

617-441-5

Cas Number:

83121-18-0

Molecular formula:

C14 H6 Cl2 F4 N2 O2

IUPAC Name:

1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea

Test material form:

solid

Test animals

Species:

rat

Strain:

other: KFM: Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Kleintierfarm Madoerin AG, CH 4414 Fuellinsdorf/Switzerland
- Age at study initiation: males: 7 weeks, females: 9 weeks
- Weight at study initiation: males: 220 - 293 g, females: 191 - 206 g
- Fasting period before study: No
- Housing: The animals were caged in groups of 5 in Makrolon type-4 cages with wire mesh lids
- Diet: ad libitum (with the exception of the exposure period), pelleted standard Kliba 343, rat maintenance diet (Klingentalmuehle AG, CH 4303 Kaiseraugst /Switzerland)
- Water: ad libitum (with the exception of the exposure period), tap water
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 45-65
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Remark on MMAD/GSD:

Particle size was measured twice 1 and 3 hours after exposure start. Approximately 38 % of the determined particles were within a size range of 1 to 7 microns.

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: the exposure chamber (H. Born & Co., Mechan. Werkstatt, CH 4313 Moehlin / Switzerland).
- Exposure chamber volume: 100 L
- Method of holding animals in test chamber: the rats were placed around the exposure chamber in separate radial polyvinylchloride tubes with their snouts and nostrils exposed to the aerosol only.
- System of generating particulates/aerosols: the test substance was supplied to the nozzle by a Grafix Exaktomat injector (Cerutti AG, Bern / Switzerland). The air flow was 1000 L/hr and air pressure was 3 atmospheres. The spray nozzle discharged into the air of the chamber.
- Method of particle size determination: Gravimetrical determination with the aid of a 4 stage cascade impactor (Casella Ltd., London/England) on selectron filters, pore size 0.2 µm and 25 mm in diameter (Schleicher and Schuell, Feldbach/Switzerland). The particle size distribution shows for each filter of the cascade impactor the portion in % of the weight of particle sediment.
- Temperature, humidity, pressure in air chamber:
Oxygen content in chamber air: A constant amount of 20 vol. % of oxygen was found to be inside the exposure chamber during the test period (measured with OXYCOM 25 D, Draegerwerk AG, Zurich/Switzerland).
Relative humidity of chamber air: The relative humidity of the chamber air varied between 26 and 32 % during the exposure period (measured with HM 14, VAISALA humidity indicator, Kuenzli Elektronik, Zurich/Switzerland)
Chamber temperature: The chamber temperature was found to be within 22.9 and 23.4°C during the exposure period (measured with Therm 3420, contact thermometer, Interstar AB, Zug/Switzerland)

TEST ATMOSPHERE
- Brief description of analytical method and equipment used:
Determination of exposure concentration: Gravimetrical determinations on selectron filters, pore size 0,2 µm and 50 mm in diameter (Schleicher and
Schuell, Feldbach/Switzerland). Air flow: 10 l/min., equal 1.25 meters/sec.
Aerosol particle size determination: Gravimetrical determination with the aid of a 4 stage cascade impactor (Casella Ltd., London/England) on selectron filters, pore size 0.2 µm and 25 mm in diameter (Schleicher and Schuell, Feldbach/Switzerland). Air flow: 17.5 L/min. (which is usually used) gives velocities through the 4 jets of 2.2, 10.2, 27.5, and 77 m/s, respectively.
The particle size distribution shows for each filter of the cascade impactor the portion in % of the weight of particle sediment.London/England)
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Remarks:

measured 5 times during exposure.

Duration of exposure:

4 h

Concentrations:

nominal concentration: 33 g/m³ air
measured concentration: 5.048 g/m³ air

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: Mortality: 5 times during the first day and daily thereafter
Symptoms: 5 times during the first day and daily thereafter
Body weights: At days 1 (day of exposure), 8 and 15 of test
- Necropsy of survivors performed: yes
- Other examinations performed: concentration (5 times during exposure), particle size (twice during exposure), oxygen content, humidity and temperature (8 times during exposure)

Statistics:

The LOGIT-Model could not be applied to the observed rates of death. The LC50 was estimated without use of a statistical model.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 038 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred.

Clinical signs:

other: Dyspnea and ruffled fur was observed in all rats, starting within 2 hours of exposure. All rats recovered within 2 days after starting the exposure.

Body weight:

The body weight gain was unaffected by the exposure procedure.

Gross pathology:

No pathologic changes were observed during the macroscopic examination of all animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met