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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
weight of evidence
Study period:
From 28 APR 1981 to 15 MAY 1981
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Relevevant 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:
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

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: in-house breeding collony
- Weight at study initiation: males: mean 199 g (range: 197 to 201 g); females: mean 203 g (range: 195 to 214 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): 23 °C
- 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: 709 mg/cubic metre air
range: 544 to 1098 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:
> 709 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 709 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 > 709 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 709 mg test substance per cubic metre (i.e. maximum technically feasible concentration; exposure ranged from 544 to 1098 mg/ cubic metre). The rats were exposed for 4 hours. 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 > 709 mg/m³ for the inhalation of dust.