Calcium sulfate

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

No data

Reliability:

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

Reference Type:

publication

Title:

An in vitro /in vivo study into the short term effects of exposure to mineral fibres.

Author:

Clouter A, Houghton CE, Bowskill CA, Hoskins JA & Brown RC.

Year:

1996

Bibliographic source:

Exp Toxic Pathol 48 (6) 484 - 486

Materials and methods

Test guideline

Qualifier:

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

Test material information

Constituent 1

Reference substance name:

Calcium sulfate

EC Number:

231-900-3

EC Name:

Calcium sulfate

Cas Number:

7778-18-9

Molecular formula:

CaSO4

IUPAC Name:

calcium sulfate

Details on test material:

- Name of test material: calcium sulfate
- Physical state: aerosol

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- 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

Vehicle:

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

Examinations

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

Statistics:

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:

no

Applicant's summary and conclusion

Conclusions:

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