Amendment and extension of "Maximum permissible concentrations of harmful substances in the workplace air", No.030, No.5007 (DV No.88, 1971) Repealed! Jurisdiction Bulgaria Year 1977 Published in Bulgarian Original/other title [Bulgarian] Izmenenie i dopălnenie na "Predelno dopustimi koncentracii na vredni veštestva văv văzduha na rabotnata zona" N°030, N°5007 (DV, br.88 ot 1971g.) Serial title Dăržaven vestnik Source 5 Aug. 1977, No.61, p.703-704. Descriptors [Primary] Bulgaria, asbestos, respirable dust, silica, threshold limit values [Secondary] asbestos cement, comment on directive, directive, replaced Subject category Chemical safety Abstract 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 Database ID 30641