Silicic acid, calcium salt

Specific investigations: other studies

Administrative data

Endpoint:

specific investigations: other studies

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

1991

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Study is not performed according to an OECD Guideline, no GLP, and the documentation is not sufficient for assessment and not convincing for an expert judgment.

Data source

Reference

Reference Type:

publication

Title:

Cell Toxicity, Hemolytic Action and Clastogenic Activity of Asbestos and its Substitute

Author:

Kimiko Koshi, Norihiko Kohyama, Toshihiko Myojo and Kazuo Fukuda

Year:

1991

Bibliographic source:

Industrial Health, 1991, 29, pp 37-56

Applicant's summary and conclusion

Executive summary:

In vitro biological effects of xonotlite fibers were assessed, such as the cell toxicity in Chinese hamster lung (CHL) cells, and the hemolysis of human erythrocytes. Xonotlite had a fibrous form about 5 um in length and less than 0.1 um in diameter. Survival of CHL cells in the absence or presence of xonotlite fibers was determined by colony-forming efficiency after 7 days from a single-cell suspension. The hemolytic activity of xonotlite fibers was calculated from the average optical density of three replicates and was expressed as a percentage of the optical density of the totally lysed control (100%). For cytotoxicity the toxic doses (TD50: the amounts of fibers necessary to inhibit the colony-forming efficiency of CHL cells by 50%) of fibers was determined. The TD50 of fibrous xonotlite was more than 50 ug/ml. For hemolysis the hemolytic doses (HD50: dust dose necessary to cause 50% hemolysis of human erythrocytes) of fibrous xonotlite was determined. To achieve 50% hemolysis, 380 ug/ml of xonotlite was required.