Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Engineering controls in mine assay laboratories.

Authors
Hall-RM; Sheehy-JW; Zimmer-AT
Source
Appl Occup Environ Hyg 1998 Sep; 13(9):646-655
NIOSHTIC No.
20025818
Abstract
An extensive literature search and professional contacts, who have performed industrial hygiene surveys in mine assay laboratories, suggested that mine assay workers are potentially exposed to a wide variety of chemical hazards, including lead, arsenic, silica, and mercury. As a result, the National Institute for Occupational Safety and Health (NIOSH) has undertaken a study to evaluate and disseminate control technology information for reducing these exposures and protecting worker health in this industry. Mine assay laboratories process and analyze samples from mineral exploration and mineral ore recovery operations. Ore samples are prepared for analysis by drying, crushing, splitting, and mixing samples with lead flux. Walk-through surveys were conducted at five mine assay laboratories where effective engineering controls were identified by the literature search and the professional contacts. Two laboratories appeared to represent good engineering controls in the mine assay laboratory industry and were selected for in-depth evaluations; one was located on a mine site and the other was a commercial laboratory. Both laboratories have the potential to exceed the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 50 microg/m3 and the action level of 30 microg/m3 for lead. In the commercial laboratory arsenic exposures exceeded the NIOSH recommended exposure limit OREL) of 2 microg/m3 (ceiling limit) and have the potential to exceed the OSHA PEI. for arsenic of 10 microg/m3. Based on our study results, recommendations to reduce worker exposures are as follows: (1) monitor airborne concentrations if evidence from lab-oratory analytical data indicates increased levels of hazardous metals such as arsenic or cobalt; and (2) require workers to shower and change from work clothes to street clothes before going home. Recommendations to improve ventilation systems in mine assay laboratories are as follows: (1) increase capture velocity on the ventilation hoods in the sample preparation area by increasing the degree of enclosure; (2) use a high efficiency particulate air-filtered vacuum for cleaning in the sample preparation area; and (3) increase exhaust volumes and improve hood design of canopy hoods in fire assay areas to control convection currents generated by furnaces.
Keywords
Engineering-controls; Monitoring-systems; Air-quality; Air-quality-control; Air-quality-measurement; Air-quality-monitoring; Chemical-manufacturing-industry; Chemical-processing; Chemical-properties; Chemical-reactions; Ventilation; Ventilation-equipment; Ventilation-hoods; Ventilation-systems; Particulate-sampling-methods; Particulates; Heavy-metals
CODEN
AOEHE9
CAS No.
7439-92-1; 7440-38-2; 7631-86-9; 14808-60-7; 7439-97-6
Publication Date
19980901
Document Type
Journal Article
Fiscal Year
1998
NTIS Accession No.
NTIS Price
Issue of Publication
9
ISSN
1047-322X
NIOSH Division
DSHEFS; DPSE
Source Name
Applied Occupational and Environmental Hygiene
State
OH
TOP