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Toxicological information

Repeated dose toxicity: inhalation

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Administrative data

short-term repeated dose toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
No data
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Study lacks sufficient experimental details and does not assess parameters of a guideline study.

Data source

Reference Type:
An in vitro /in vivo study into the short term effects of exposure to mineral fibres.
Clouter A, Houghton CE, Bowskill CA, Hoskins JA & Brown RC.
Bibliographic source:
Exp Toxic Pathol 48 (6) 484 - 486

Materials and methods

Test guideline
no guideline followed
Principles of method if other than guideline:
In vivo studies: rats were exposed in a nose-only facility to an aerosol of calcium sulfate at 100 mg m-3 for 6h/day, 5 days/week for 3 weeks.
In vitro studies: Type II cells from un-exposed and calcium-exposed animals were stained for alkaline phosphatase activity. In addition, type II cells were exposed in vitro to calcium sulfate over night and then stained for alkaline phosphatase activity.
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Calcium sulfate
EC Number:
EC Name:
Calcium sulfate
Cas Number:
Molecular formula:
calcium sulfate
Details on test material:
- Name of test material: calcium sulfate
- Physical state: aerosol

Test animals

Fischer 344
Details on test animals or test system and environmental conditions:
- Source: Harlan Olac.
- Age at study initiation: no data
- Weight at study initiation: 130 - 150 g

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
other: no data
Remarks on MMAD:
MMAD / GSD: No data
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
3 weeks
Frequency of treatment:
6 h/day for 5 d/week
Doses / concentrations
Dose / conc.:
100 other: mg/m3
No. of animals per sex per dose:
36 males/group
Control animals:
not specified
Positive control:
No data


Observations and examinations performed and frequency:
Biochemical analyses: protein and non-protein sulphydryl concentrations and γ-GT activity.
Macrophages/alveoli were counted in the H & E sections.
Sacrifice and pathology:
Lungs from 5 % of the animals were formalin fixed, sectioned and stained (H & E). Other lungs were lavaged (saline 8 mL, 0.15 M) the lavage centrifuged (300 g, 20 min) and the supernatant used for biochemical analyses.
Other examinations:
No data
No data

Results and discussion

Results of examinations

Details on results:
Histopathology: no significant difference was found between groups in the number of macrophages per alveolus in exposed animals.
BAL: exposure did not alter the protein concentration or γ-GT activity. NPSH levels were increased in animals exposed to calcium sulfate.
Type II cells: the viability of type II pneumocytes from rats pre-exposed to calclium sulfate was unchanged when compared to cells from unexposed animals. Cells from animals incubated with calcium sulfate showed no change in alkaline phosphatase staining at any concentration.

Effect levels

Remarks on result:
other: based on the number of alveoar macrophages there was no inflammatory response, although inflammation may have been localised to the acini region.

Target system / organ toxicity

Critical effects observed:

Applicant's summary and conclusion

In vivo: based on the number of alveoar macrophages there was no inflammatory response, although inflammation may have been localised to the acini region.