Silica Monitoring in ConstructionChicago

In August 2024, OSHA cited a Chicago countertop fabrication shop for eight egregious willful, four willful, and 20 serious violations, proposing more than $1 million in penalties.

Workers were exposed to silica levels nearly six times the PEL. A 31-year-old worker required a double lung transplant, and his 59-year-old father was awaiting a lung transplant.

OSHA's engineered stone focused inspection initiative has conducted 371 inspections and 574 samples nationwide. 117 exceeded the PEL (20%), including 22 at five times the PEL.

OSHA has inspected only several hundred of the estimated 10,000+ US employers in the countertop fabrication industry.

Handheld and walk-behind concrete saws, angle grinders with diamond blades, and surface grinders generate concentrated respirable silica dust during concrete cutting, scoring, and surface preparation. Without wet methods or vacuum dust collection, exposures can exceed the OSHA PEL by 50 to 100 times. The OSHA Table 1 requires integrated water delivery or vacuum dust collection for these tools, but compliance verification through personal air monitoring remains essential on sites using alternative control measures.

Tuck-pointing involves cutting out deteriorated mortar joints from brick and stone walls using handheld grinders fitted with mortar raking blades. This operation generates extremely high RCS concentrations because the grinding action pulverises silica-containing mortar and brick in a confined work zone close to the operator breathing zone. OSHA identified tuck-pointing as one of the highest-exposure construction tasks, with uncontrolled exposures exceeding the PEL by factors of 100 or more.

Demolition of concrete structures, brick buildings, and stone facades generates silica-laden dust from mechanical breaking, sawing, and hydraulic crushing. Interior renovation work in enclosed spaces concentrates dust levels. Workers performing selective demolition in occupied buildings must manage dust containment to protect both demolition workers and building occupants.

Road construction involving concrete pavement breaking, milling, and resurfacing generates RCS from contact with silica-containing concrete and aggregate. Bridge deck grinding, median barrier cutting, and kerb removal produce sustained silica exposure for operators and ground crew. Large-scale infrastructure projects involving tunnelling and excavation in rock formations containing quartz add underground silica exposure to the construction programme.

Sanding joint compound on drywall surfaces generates fine airborne dust that may contain crystalline silica depending on the formulation. While newer joint compounds may use non-silica fillers, verification of product composition and exposure monitoring confirms whether the silica standard applies. Workers sanding overhead and in enclosed rooms face sustained inhalable dust exposure across the work shift.

Typical Worker Groups

Common similar exposure groups (SEGs) assessed for this sub-category.

Regulatory Context

OSHA regulates RCS in construction under 29 CFR 1926.1153, which took effect in September 2017. The standard provides two compliance options: Table 1, which specifies engineering controls and work practices for 18 common construction tasks, and the performance option requiring exposure assessment and controls to maintain exposure below the PEL of 50 µg/m³ TWA. Medical surveillance is required for workers exposed above the action level of 25 µg/m³ for 30 or more days per year, including initial and periodic chest X-rays and pulmonary function tests. OSHA maintains a National Emphasis Program on silica that authorises proactive inspections at construction sites with visible dust emissions. Silica violations consistently rank among OSHA top 10 most-cited standards. Penalties for serious violations reach $16,550 per violation, with willful or repeat violations up to $165,514.