Health hazard evaluation report: HETA-2000-0226-2890, Foeste Masonry, Cape Girardeau, Missouri.
Foeste masonry recently received an OSHA citation for overexposure of workers to crystalline silica during the dry cutting of brick. Foeste subsequently purchased several brick/block cutoff saws equipped with water dust suppression. Until Foeste could show that exposures were adequately controlled, Foeste was required by OSHA to enroll the operators in a respiratory protection program (fit testing and use of half mask, cartridge respirators). On April 3, 2000, Foeste Masonry requested a Health Hazard Evaluation (HHE) to assess the effectiveness of wet dust suppression during the cutting of brick and block. On May 8, 2000, NIOSH investigators met with Foeste representatives to discuss sampling procedures for collecting airborne dust samples. Environmental measurements of airborne particulate were obtained on May 9 -10,2000. NIOSH investigators determined that dry cutting can lead to intense exposures to silica dust. Such exposures are likely to be very hazardous to workers operating the saws and working in their vicinity. NIOSH recommends that wet cutting be used when ever possible. The sampling undertaken in this study indicates that wet cutting, undertaken using the manufacturer's guidelines, generally leads to exposures to silica dust below the OSHA PEL. It is recommended that saw operators continue to wear at least a NIOSH-approved, disposable respirator, especially when wet cutting for two hours or more. If dry cutting brick or block is necessitated by the building design a Powered Air Purifying Respirator (PAPR) should be worn and the cutting time should be limited. Routine evaluation of dust exposures is desirable to ensure that the workers are adequately protected, especially for brick or block of high silica content.
Silica-dusts; Masons; Stonemasons; Dusts; Dust-suppression; Dust-particles; Dust-masks; Dust-control-equipment; Dust-control; Particulate-dust; Particulates; Cutting-tools; Region-7; Respiratory-protective-equipment; Respiratory-system-disorders; Respirators; Pulmonary-system-disorders; Hazard-Confirmed