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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:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
It was not verified that the saturated dust concentration is the maximum possible.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
no
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Bantin and Kingman Ltd., Grimston, Aldbrough, Nr. Hull
- Age at study initiation: 7-8 weeks
- Weight at study initiation: 190-370 g
- Housing: solid floor polypropylene cages furnished with sterilised sawdust, in groups of 5
- Diet (e.g. ad libitum): Rat and Mouse No. 1 Expanded Diet (BP Nutrition (UK) Ltd., Stepfield, Witham, Essex), ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: for a minimum of 3 days before exposure

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 50 ± 10
- Air changes (per hr): 8-10

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 Perspex exposure chamber
- Exposure chamber volume: 7 L
- Rate of air: 15 L/min
- System of generating particulates/aerosols: Timbrell dust generator was used to produce the atmosphere
- Method of particle size determination: CS5 cascade impactor was employed with 6 separation stages covering the particle aerodynamic mass median diameter range 0.35-4 µm. Upper class limits for the 6 stages were 0.35, 0.5, 0.75, 1.0, 2.0 and 4.0 microns.

TEST ATMOSPHERE
- Brief description of analytical method used: The absolute concentration of the atmosphere generated was measured gravimetrically before and after each exposure period using a glass fibre filter disc placed adjacent to the outside wall of the exposure chamber.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter): 0.87 µm
Analytical verification of test atmosphere concentrations:
yes
Remarks:
gravimetric determination
Duration of exposure:
4 h
Concentrations:
0.41 mg/L (analytical concentration)
No. of animals per sex per dose:
10
Control animals:
yes
Details on study design:
The rats were observed for toxic or pharmacological effects during exposure and subsequently at least twice daily through a 14 day observation period. All observations were recorded daily. Body weights were determined on the day before exposure, immediately after exposure and on days 1, 3, 7, 10 and 14 after the day of exposure. Mortalities were recorded at daily intervals. Gross necropsy was performed at the end of the study.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 0.41 mg/L air
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: no mortality observed
Mortality:
No deaths occurred during exposure or during the observation period as a result of exposure to the test material. One male treated rat suffocated as a result of turning around in the restraining tube. A planned sacrifice was made of one female treated rat, one male control and one female control rat after exposure to assess the degree of primary lung irritation.
Clinical signs:
Treated rats had chromodacryorrhoea for a few hours after exposure and their pelts remained stained red throughout the observation period.
Control rats had nasal secretion and chromodacryarrhaea on the day of exposure presumably an irritant effect of the restraining tubes. Their pelts were ruffled, a condition which persisted throughout the observation period.
Body weight:
The mean body weights of the male and female control rats rose throughout the experiment, slowly until day 2 but thereafter more rapidly. The mean body weights of the treated rats were depressed following exposure but raised steadily throughout the observation period.
Gross pathology:
All the control rats and 6 male and 7 female treated rats, sacrificed after the 14 day observation period showed a moderate degree of pulmonary congestion and edema was present in some control rats. A similar degree of congestion was also noted in the female treated rat examined immediately after exposure, but congestion was more severe in the male, which had suffocated. No congestion was noted in the two control rats sacrificed at the same time, and no other abnormalities were noted in any of the control animals. The treated rats examined after exposure had red stained pelts.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Under the conditions chosen, the test substance was practically non-toxic.