[Data for the substantiation of the maximum permissible exposure level of armos fiber dust in the air of the work area].

The 'Armos' fibre dusts are characterized by low cytotoxicity, absence of fibrogenicity, display non-toxic properties in single exposures with no skin-irritating and sensibilizing effects. In repeated introduction into the stomach, the trachea, and if inhaled, these dusts displayed weak toxic properties. Dust concentrations at 10 mg/m3 are in proximity to the threshold one. The MAC for 'Armos' dusts in working zone areas was recommended at 5 mg/m3 (4th class of hazardness).