[inglés] Amendment and extension of "Maximum permissible concentrations of harmful substances in the workplace air", No.030, No.5007 (DV No.88, 1971) Derogado! Jurisdicción Bulgaria Ańo 1977 Publicado en búlgaro Título original / otro título [búlgaro] Izmenenie i dopălnenie na "Predelno dopustimi koncentracii na vredni veštestva văv văzduha na rabotnata zona" N°030, N°5007 (DV, br.88 ot 1971g.) Título de revista periódica Dăržaven vestnik Fuente [inglés] 5 Aug. 1977, No.61, p.703-704. Descriptores [Principales] Bulgaria, amianto, polvos respirables, sílice, valores umbrales [Secundarios] cemento-amianto, comentario de directiva, directiva, recambio Categoría Riesgos químicos Resumen [inglés] This directive provides for changes in the exposure limits for asbestos dust: 6mg/m3 for asbestos cement containing <10% asbestos; 8mg/m3 for bakelite and rubber dust containing <10% asbestos; 2mg/m3 for dust containing >10% asbestos; 0.2mg/m3 for pure asbestos dust with fibres <3ľm; 3 particles/cm3 for asbestos fibres <3ľm in diameter. Exposure limits for silica dust are given according to the silica content of the respirable fraction. Commentaries on the new values by M. Dobreva, "New hygiene standards for dust containing quartz and asbestos", are published in Higiena i zdraveopazvane, Sofija, 1978, No.3, p.233-237. CIS No. 79-46 Número de registro 30641