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Specific investigations: other studies

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specific investigations: other studies
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Study period:
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 Type:
Cell Toxicity, Hemolytic Action and Clastogenic Activity of Asbestos and its Substitute
Kimiko Koshi, Norihiko Kohyama, Toshihiko Myojo and Kazuo Fukuda
Bibliographic source:
Industrial Health, 1991, 29, pp 37-56

Materials and methods

Results and discussion

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.