29 CFR 1926.1153
Respirable Crystalline Silica (Construction)
Worker exposure to respirable crystalline silica dust from cutting, grinding, drilling, and demolishing concrete and masonry on construction sites.
Who needs it
Every construction employer whose crews cut, core, grind, chip, or demolish concrete — including small residential contractors, not just large commercial firms.
What the test involves
The standard sets a permissible exposure limit of 50 micrograms per cubic meter of air as an 8-hour time-weighted average, with an action level of 25 micrograms per cubic meter that triggers exposure assessment and medical surveillance obligations. Employers may either follow Table 1, which pairs common construction tasks with specified dust controls such as water delivery or vacuum dust collection plus required respiratory protection for given durations, or perform their own exposure assessment and control exposures below the limit. The rule also requires a written exposure control plan, a competent person to implement it, restrictions on housekeeping practices like dry sweeping and compressed air where alternatives exist, medical surveillance for workers wearing respirators above the threshold, and worker training.
Common misconceptions
- Fully implementing a Table 1 task is the compliance path itself — an employer following Table 1 correctly does not have to separately measure exposures for that task.
- A dust mask is not the primary control. The standard is built around engineering controls such as wet cutting and on-tool vacuum extraction, with respirators supplementing them.
- Outdoor work is not automatically exempt. Cutting concrete outdoors can still generate exposures well above the limit.
- It applies to residential and small-crew work. There is no small-contractor exemption from the standard.
Official source
We summarize scope and purpose only. The full text belongs to the issuing body — read it at the official source. U.S. Occupational Safety and Health Administration