2-Propyl-4-methyl-6-(1-methylbenzimidazol-2-yl)benzimidazole

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-10-18 to 2011-11-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure in accordance with national standard methods (China) with acceptable restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: The Guidelines for the Testing of Chemicals (State Environmental Protection Administration of China, 2004, 5) and The Guidelines for the Hazard Evaluation of New Chemical Substances (State Environmental Protection Administration of China, 2004, 6)

Principles of method if other than guideline:

limit test, similar to OECD 403; groups of animals are exposed to a limit concentration (limit test) for a predetermined duration of 4 hours in oder to determine a LC50 value.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-Propyl-4-methyl-6-(1-methylbenzimidazole-2-yl)benzimidazole

IUPAC Name:

2-Propyl-4-methyl-6-(1-methylbenzimidazole-2-yl)benzimidazole

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

the sample was milled by a micro-mill and stored in a desiccator for generating test dust

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS- Source: Vital River Lab Animal Technology Co., Ltd., - Age at study initiation: no data- Weight at study initiation: 180 -220g- Housing: individual- Diet (e.g. ad libitum): ad libitum (except during exposure); Beijing Keao Xieli Laboratory Diet Co. Certificate No. SCXK (Jing) 2009-0012)- Water (e.g. ad libitum): ad libitum (except during exposure)- Acclimation period: no dataENVIRONMENTAL CONDITIONS: kept in individual ventilated cages

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/Method of holding animals in test chamber: Nose-only exposure chamber, constructed as individual plastic rat holders which were positioned in two tiers around the outsides, so that only the noses of the rats were exposed to the generated dust.- System of generating particulates/aerosols: dust generator- Method of particle size determination: not determinedTEST ATMOSPHERE- Brief description of analytical method used: Five gravimetric samples of chamber atmosphere were drawn from the breathing zone of the rats during exposure at about 60-minutes intervals through a filter cassette holding a pre-weighed CPVC fiber filter by a SIBATA air sampler (calibrated by a foam-film flowmeter). The sampling flow rate was 10 L/min and the sampling duration was 15 seconds. The CPVC fiber filters were placed in a desiccator for 24 hours and then weighed before sampling. They were reweighed by the same manner 30 minutes after sampling. The concentration of the test substance was accounted from the mass on the filter. The calculation formula of concentration was as follows:C(mg/m3) = weight of filter post-sampling (g) – weight pre-sampling (g)/sample volume (L) x 10^6- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5496+-613 mg/m3 or 5.496 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; bodyweight were measured on day 3, 7, 14- Necropsy of survivors performed: yes- Other examinations performed: mortality and clinical signs

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 496 mg/m³ air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

no mortality

Clinical signs:

other: no toxic signs

Body weight:

the weights of rats were increasing during the test period

Gross pathology:

no gross patholgical changes

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The substance is considered to be non-toxic under these test conditions.