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Toxicological information

Repeated dose toxicity: inhalation

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Administrative data

Endpoint:
chronic toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: read-across from a slightly water soluble chromate
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Morphogenesis of alveolar bronchiolization.
Author:
Nettesheim, P. and A. K. Szakal
Year:
1972
Bibliographic source:
Lab Invest.26(2): 210-9.

Materials and methods

Principles of method if other than guideline:
Chronic inhalation toxicity test: mice were exposed to test substance dust 5 and a half hour per day, 5 days per week, for 18 months.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
calcium chromate (CaCrO4) dust, ozonized gasoline fume

Test animals

Species:
mouse

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
whole body
Duration of treatment / exposure:
18 months
Frequency of treatment:
5 and a half hours a day, 5 days a week
Doses / concentrations
Remarks:
Doses / Concentrations:
13 mg/m3 of calcium chromate
Basis:
nominal conc.

Examinations

Other examinations:
bacteriologic, virologic, and parasitologic testing

Results and discussion

Results of examinations

Clinical signs:
not examined
Mortality:
not examined
Body weight and weight changes:
not examined
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not specified
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

a concentration of 13 mg/m3of calcium chromate tested: non-carcinogenic morphological changes seen, no NOAEL identified

Applicant's summary and conclusion

Conclusions:
Non-cancerous morphological changes in the lower respiratory tract.
Executive summary:

Nettesheim et al. (1972) exposed mice (C57BL/6) to filtered air, ozonized gasoline fumes or calcium chromate dust (mean geometric diameter 0.2 μm) for five and a half hours/day, five days/week. The dust was dispensed into the inlet air at a concentration of 13 mg/m3. Eighteen months after the start of the exposure, 15 mice were removed from each chamber and used for bacteriologic, virologic, and parasitologic testing and for histopathology. Results showed necrosis and hyperplasia of the bronchial and alveolar epithelia, inflammation of the underlying bronchial and bronchiolar connective tissues, and hyperplasia or atrophy of surrounding lymph nodes.