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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16 August 1984 to 02 May 1986
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1984

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
yes
Remarks:
(only two test concentrations)
Qualifier:
according to
Guideline:
EPA OPP 81-3 (Acute inhalation toxicity)
Deviations:
no
GLP compliance:
yes
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Physical state: solid
- Storage condition of test material: room temperature

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Housing: stainless steel wire mesh cages
- Diet: ad libitum
- Water: tap water ad libitum
- Acclimation period: 6-8 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20-25 °C
- Humidity: 48-77 %
- Air changes: 26 times per hour
- Photoperiod: 12 hours light / 12 hours dark

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure chamber volume: 40 L
- System of generating particulates/aerosols: Rehma type 504104 nebulizer
- Method of particle size determination: measured using a Marple personal cascade impactor, model 296. Samples were taken through the inlet adaptor at nose level at 1.5 L/min at 105 and 165 minutes after the start of exposure. Directly after sampling, the filters were extracted with methanol and the test material measured spectrophotometrically.
- Temperature, humidity, pressure in air chamber: 23.4-23.8 °C; 60.1-65.0 %

TEST ATMOSPHERE
- Brief description of analytical method used: samples of test atmosphere were taken through a 6cm plastic tube at 2 L/min for 2 minutes. After sampling, filters and the silica were extracted with dichloromethane and amounts of test material measured spectrophotometrically.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 2.11-2.57 µm (105 minutes); 2.00-2.61 µm (165 minutes) / 2.89-3.13 (105 minutes); 2.90-3.14 (165 minutes)
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
240 min
Concentrations:
0, 540 and 700 mg/m^3 (nominal)
133-233 mg/m^3 (lowest dose) - 250-326 mg/m^3 (highest dose)
No. of animals per sex per dose:
Five
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: during exposure, respiratory frequencies if two males and two females were recorded; At 1.5, 18, 24 and 48 hours after exposure each animal was checked for toxic symptoms and then observed daily
- Necropsy of survivors performed: yes
- Other examinations performed: organ weights (lungs and trachea) and organ histopathology

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 250 mg/m³ air (analytical)
Based on:
test mat.
Remarks on result:
other: maximum attainable concentration (limit dose)
Mortality:
No deaths were reported during the study.
Clinical signs:
A temporarily decreased reactivity and locomotor activity of the rats suggested a slight effect on the nervous system when compared to controls.
Body weight:
No effects were observed.
Gross pathology:
All animals appeared normal. No macro- or microscopic abnormalities were detected which could be attributed to the test material.
Other findings:
- Organ weights: no changes in lung weights were observed.
- Histopathology: minor changes, not attributable to the test material, were observed.
- Other observations: respiratory frequencies were depressed in the test groups when compared to the controls.

Applicant's summary and conclusion

Interpretation of results:
other: Not classified in accordance with EU Criteria
Conclusions:
Under the conditions of the test, the LC50 of the test material was >250 mg/m³. A decreased respiratory frequency, observed during the exposure period, indicates an irritating action of the test material on the respiratory system. Further observations at 1.5 hours after exposure suggest a slight depression of the test material on the behaviour of the treated animals.
Executive summary:

In a GLP compliant acute inhalation study conducted in line with standardised guidelines EPA OPP 81-3 and partly in line with EU Method B.2, the acute inhalation toxicity of the test material was determined.

Under the conditions of the test the LC50 of the test material in rats was determined to be >250 mg/m3. A decreased respiratory frequency, observed during the exposure period, indicates an irritating action of the test material on the respiratory system. Further observations at 1.5 hours after exposure suggest a slight depression of the test material on the behaviour of the treated animals.