Calcium dihydroxide

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Outdated technology and examinations, no doses specified.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

The Prevention of Silicosis: Experimental Investigations on the Action of Certain Non-Siliceous Dusts and Silica in the Origin and Development of Silicosis

Author:

Naeslund C

Year:

1940

Bibliographic source:

Ind. Hyg. Toxicol 22: 1-30

Reference 2

Reference Type:

secondary source

Title:

The Prevention of Silicosis: Experimental Investigations on the Action of Certain Non-Siliceous Dusts and Silica in the Origin and Development of Silicosis

Author:

Naeslund C

Year:

1940

Bibliographic source:

cited in: TNO BIBRA International Ltd., Toxicity Profile Calcium hydroxide, 1988

Materials and methods

Principles of method if other than guideline:

Method: other: no data

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Automatically generated during migration to IUCLID 6, no data available

IUPAC Name:

Automatically generated during migration to IUCLID 6, no data available

Details on test material:

- Test substance: Cement

Test animals

Species:

other: rabbits and guinea pigs

Strain:

not specified

Sex:

not specified

Administration / exposure

Route of administration:

inhalation

Details on inhalation exposure:

These tests were carried out on the whole according to the same technic as earlier investigations concerning the promotive capacity of certain iron ores and granite leptite for silicosis (Naeslund, 1938).
Some changes were made however, to enable the simultaneous execution of a great number of exposures. By means of good-sized, strong fans, the finely powdered dusts were distributed in 6 different chambers of iron plate equipped with a lid of glass, in each of which up to 10 animals (rabbits and guinea pigs) were placed.
The arrangements with dust flasks, heating, agitation and taking of samples were the same. On the other hand, the percentage of dust was considerably increased and amounted, as a rule, to between 500,000 to 5,000,000 articles (under 10 µm in size) per cubic centimeter. The time of exposure in these dust chambers was not more than approximately 5 hours daily in order to render possible two (sometimes three) different series of tests in each chamber the same day. This was necessary because of the long experimental period and the large number of series.

Duration of treatment / exposure:

Rabbit: 6 months, 2 days
Rabbit: 4 months, 18 days
Guinea pig: 8 months, 14 days

Frequency of treatment:

5 h/d

Doses / concentrations

Remarks:

Doses / Concentrations:
500000 - 5000000 particles/cm3
Basis:

No. of animals per sex per dose:

2 rabbits and 1 guinea pig

Details on study design:

Rabbits and guinea pigs were exposed daily for 5 h to a poorly-defined concentration of calcium hydroxide dust.

Results and discussion

Results of examinations

Details on results:

The exposure seemed to predispose the animals to a variety of fatal lung infections. Structural changes (epithelial proliferation and thickening of the alveolar walls) in the lungs were seen in a guinea pig that survived exposure for 8.5 months and in two rabbits that survived after an exposure of 4.5 or 6 months.

Target system / organ toxicity

Critical effects observed:

not specified