Data on establishing the MPEL for the dust of a polymineralic potassium ore in the air of a work area]

The article contains data on the norming principles for and the biologic action of polymineralic potassium dusts. The analysis and comparison of experimental and clinical data presented potassium ore as a substance characterized by low toxicity and weak fibrogenic action. In animal studies, the general toxic action of potassium aerosols exceeded the fibrogenic effects. MAC was suggested for working zone areas at 5 mg/m3 (3rd class of hazards).     

Data for substantiation of MPEL of 1,2,4-triazole in the workplace air

1,2,4-Triazole belongs to the 3-d degree moderately dangerous compounds, according to the parameters of acute intragastric toxicity (LD50). Single and repeated applications of the substance on the skin of rats does not lead to local irritating or skin-resorptive effects. In the native state the substance produces moderate irritating effects on the eye mucosa of rabbits. It produces a moderately manifest cumulative effect of the functional character (Kcum greater than 5). 1,2,4-Triazole belongs to the 2-nd degree of danger according to LC50. The threshold of acute inhalational exposure (Li(mac)) 226.6 mg/m3, the threshold of chronic inhalational exposure (Lim(ch)), 19.8 mg/m3. The substance does not have mutagenic and embryotropic properties. 5 mg/m3 is recommended as the maximum allowable concentration for 1,2,4-triazole in the air of the working area.     

The establishment of the MPEL for carboxylic acid derivatives in the air of a work area by using mathematical models]

Reports of MACs for carboxylic acid derivatives as sodium methoxyacetate (SMOA), methyl chlorpropionate (MCP) and acetoacetic ether (AAE). SMOA shows low toxicity, no cumulation and specific action MCP demonstrates moderate toxicity, low cumulation no specific action in concentrations close to Limac. AAE presents toxicity low in oral usage and moderate when inhaled, low cumulation, no irritation and sensitization. Tentative safe level of injury and MAC estimated for the aforesaid substances together with toxicity parameters compared with the substances studied before allowed the authors to set the MAC of SMOA--10, MCP--2, AAE--10 mg/m3.     

Data on the establishment of group MPEL for natural and modified colophony in the workplace air

The results of the toxico-hygienic study of 12 types of rosins are presented. It is established that these compounds are moderately hazardous products with slightly pronounced local irritating and skin resorptive effect accompanied by moderate sensitizing activity. Rosins' cumulative characteristics are not manifested at the lethal level. Lim(ac) are within 110-193 mg/m3 and Lim(ch) within 38.0-42.0 mg/m3. The analyzed types of rosins possess polytropic general toxicity with primary impact on the functional state of liver, kidneys and the nervous system. The above studies have enabled one to recommend group MAC for rosins in the workplace air at the level of 4 mg/m3 and their marking as allergens.