2,2'-[ethylenebis(oxyphenyl-2,1-eneazo)]bis[N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 5 May 1981 to 19 MAY 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Relevant methodological deficiencies

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Company guideline

Deviations:

no

Principles of method if other than guideline:

test for acute toxicity after inhalation exposure (dust exposure in open, dynamic system)

GLP compliance:

no

Remarks:

study was performed previous to GLP implementation

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-[(4-chloro-2-nitrophenyl)azo]-N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

EC Number:

235-462-4

EC Name:

2-[(4-chloro-2-nitrophenyl)azo]-N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxobutyramide

Cas Number:

12236-62-3

Molecular formula:

C17H13ClN6O5

IUPAC Name:

2-[(4-chloro-2-nitrophenyl)diazenyl]-3-oxo-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)butanamide

Test material form:

solid: bulk

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: own breed
- Weight at study initiation: males: mean 199 g (range: 196 to 201 g); females: mean 205 g (range: 195 to 216 g)
- Housing: plastic cages
- Diet: Standard husbandry diet Altromin 1324 (Altromin GmbH, Lage/Lippe, Germany), ad libitum
- Water: tap water, ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 °C (in exposure cylinder)
- other measurmenst during dust exposure: 21% oxygen, 5000 ppm carbon dioxid, no carbon monoxide

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: cylindrical plastic cage
- Exposure chamber volume: 60 L
- Method of holding animals in test chamber: each animal was in a plastic tube
- Source and rate of air: laminar air stream of 900 L/hour at 1 bar from above
- System of generating particulates/aerosols: dustgenerator "Wright Dust Feed Mechanism" of L. Adams Ltd., London, UK
- Treatment of exhaust air: exhaust device at the basement of the exposure chamber in line with a diverse system of filters

TEST ATMOSPHERE ANALYSIS
- Brief description of analytical method used: gravimetric measurement: The test atmosphere was sucked through filters ("Experimentiertrommelgasfilter", Elster AG, Mainz-Kastel, Germany; as well as a fibre glass and a membrane filter (diameter of pores 0.65 µm) Sartorius Membranfilter GmbH, Göttingen, Germany) by means of vacuum (at 1200 L/h). The exhaust quantity was 10 L/min. The filters were positioned in an exsiccator 24 h before use. The filters were weighed before and after each measurement by means of electrical scales (Sartorius-Werke GmbH, Göttingen, Germany).
- Waste treatment: After the filters 2 washing bottles, filled with water and polyglycol 400, were placed. Dust leaving the test chanmber due to high pressure was sucked into a gas cleaning station.

TEST ATMOSPHERE
- Particle size distribution: > 0.65 µm

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetric measurement

Duration of exposure:

4 h

Concentrations:

mean: 1274 mg/cubic metre air
range: 521 to 2511 mg/cubic metre air
Concentration applied was the maximum technically feasible concentration.

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily except on weekends
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1 274 mg/m³ air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: maximum feasible concentration tested; no animals died within the 14 day observation period

Any other information on results incl. tables

- no deaths occurred

- during dust exposure rats showed unsteady breathing

- behaviour of the rats was normal during the 14 days observation period

- body weight development was normal during the 14 days observation period

- no gross organ changes were seen at necropsy

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Exposure of male and female Wistar rats to 1274 mg/m³ test item (i.e. maximum technically feasible concentration) for 4 hours did not result in the death of the animals during a 14 day observation period, resulting in a LC50 value of > 1274 mg/m³.

Executive summary:

Acute inhalation toxicity of the test item has been investigated in male and female Wistar rats. Mean dust exposure concentration was 1274 mg test substance per cubic metre (i.e. maximum technically feasible concentration; exposure ranged from 521 to 2511 mg/ cubic metre). The rats were exposed for 4 hours, nose only. All animals survived the 14 day observation period. No macroscopic visible changes were observed at necropsy at the end of the observation period, resulting in a LC50 value of > 1274 mg/m³ for the inhalation of dust.