Silica Exposure (Respirable Crystalline Silica)
Respirable crystalline silica exposure refers to the inhalation of fine silica dust particles generated by cutting, grinding, drilling, or crushing materials containing crystalline silica such as concrete, brick, stone, morite, and sand. OSHA's silica standard for construction (29 CFR 1926.1153) sets a permissible exposure limit (PEL) of 50 micrograms per cubic meter of air over an 8-hour time-weighted average. Overexposure can cause silicosis, lung cancer, chronic obstructive pulmonary disease, and kidney disease.
Crystalline silica is one of the most significant occupational health hazards in the construction industry. Activities that generate respirable silica dust are ubiquitous on construction sites, including concrete cutting and sawing, tuckpointing and mortar grinding, jackhammering, rock drilling, tunnel boring, and abrasive blasting with sand. OSHA estimates that approximately 2.3 million workers in the United States are exposed to respirable crystalline silica on the job, with construction workers accounting for a substantial portion of that number.
OSHA's construction silica standard, which took full effect in 2018, establishes specific compliance requirements beyond the PEL. The standard includes Table 1, which specifies engineering controls and work practices for 18 common construction tasks that generate silica dust. Employers who fully implement the controls listed in Table 1 for a given task are not required to conduct air monitoring for that task. For tasks not covered by Table 1, employers must assess exposure through air monitoring and implement controls to keep exposure below the PEL. When exposures exceed the action level (25 micrograms per cubic meter), employers must provide medical surveillance including chest X-rays and lung function tests every three years.
Compliance with the silica standard requires a multi-faceted approach including exposure assessments, engineering controls (wet methods, local exhaust ventilation, enclosed cabs), respiratory protection programs, medical surveillance, worker training, and detailed recordkeeping. Workers exposed above the action level must receive training on health hazards of silica, control methods, the purpose and use of respirators, and the medical surveillance program. Training records, exposure assessment results, and medical surveillance documentation must all be maintained and made available to workers and OSHA upon request. Integrating silica training tracking with other safety certifications ensures that construction companies meet every element of this comprehensive standard.