2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole)

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

Inhalation toxicity was tested according to the method of Sachsse et al. (1973): Measurement of inhalation toxicity of aerosols in small laboratory animals. In: Proceedings of the Europ. Soc. for the Study of Drug Toxicity, Vol. XV, pp. 239-251, Zurich, June 1973.

GLP compliance:

no

Remarks:

prior to GLP

Test material

Test material information

Constituent 1

Reference substance name:

2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole)

EC Number:

230-426-4

EC Name:

2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole)

Cas Number:

7128-64-5

Molecular formula:

C26H26N2O2S

IUPAC Name:

5-tert-butyl-2-[5-(5-tert-butyl-1,3-benzoxazol-2-yl)thiophen-2-yl]-1,3-benzoxazole

Test animals

Species:

rat

Strain:

other: Tif: RAIf (SPF) strain

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: in-house
- Weight at study initiation: 190 - 195 grams
- Housing: Macrolon cages, type 4 (9 animals to a cage)
- Diet: rat food - NAFAG, Gossau SG; ad libitum
- Water: ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 1
- Humidity (%): 55 +/- 5
- Photoperiod (hrs dark / hrs light): 10/14

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose/head only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: "Grafix Exaktomat Injector"
- Method of holding animals in test chamber: PVC tubes
- System of generating particulates/aerosols: nozzle under a pressure of 2 atm at a rate of 20 L/min
- Method of particle size determination: Cascade Impactor with selectron filters
- Relative humidity: 32%

TEST ATMOSPHERE
- Brief description of analytical method used: gravimetry
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle: air

TEST ATMOSPHERE
- Particle size distribution:
> 7 µm: ca. 56%
3-7 µm: ca. 15%
1-3 µm: ca. 11%
< 1µm: ca. 18%

Analytical verification of test atmosphere concentrations:

yes

Remarks:

determined gravimetrically

Duration of exposure:

4 h

Concentrations:

1820 mg/m³ air (maximum achievable concentration)

No. of animals per sex per dose:

9 animals

Control animals:

no

Details on study design:

The animals were submitted to a necropsy at the end of the observation period.

Statistics:

The average dust concentration was gravimetrically determined.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1 820 mg/m³ air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Average dust concentration, gravimetrically determined

Mortality:

No deaths observed

Clinical signs:

other: During the 4-hour exposure period and the subsequent 14-day observation period no toxic symptoms were observed.

Gross pathology:

No substance related gross organ changes were seen.

Other findings:

aerosol concentration: 1820 +/- 69 mg/m³