Key Notes:

  • OSHA is significantly reducing the permissible limits of respirable silica at worksites.
  • Employers must utilize a regulatory control method or create an appropriate alternative.
  • These requirements should be communicated to contractors and subcontractors.

The Rule: OSHA Regulations 29 CFR §1926.1153

Beginning on September 23, 2017, the Occupational Safety and Health Administration (OSHA) will significantly reduce the Permissible Exposure Limit (PEL) for respirable crystalline silica during work at construction projects from 250 to 50 µg/m3 (micrograms of silica per cubic meter of air), averaged over an eight-hour day. This new PEL applies to all occupational exposures to respirable silica in construction work, except where employee exposure will remain below 25 µg/m3.

The new standard requires employers to limit worker exposure to respirable silica and take steps to protect workers. There are two options for employers to comply with the standard: use a control method described in Table 1 of 29 CFR §1926.1153(c)(1), which is a list of proper engineering controls, work practices and respiratory protection required for 18 specific tasks; or measure workers’ exposure to silica and independently decide which control methods most effectively limit exposure to the PEL in workplaces.


Regardless of which exposure control method is used, all construction employers covered by the standard are required to:

  • Establish and implement a written exposure control plan that protects workers, including restrictions to work areas where high exposures may occur
  • Designate a competent person to implement the written exposure control plan
  • Restrict housekeeping practices that expose workers to silica where feasible alternatives are available
  • Offer medical exams – including chest X-rays and lung function tests – every three years for workers who are required by the standard to wear a respirator for 30 or more days per year
  • Train workers on work operations that result in silica exposure and ways to limit exposure
  • Keep records of workers’ silica exposure and medical exams

Additionally, employers who do not use the control methods in Table 1 must:

  • Measure the amount of silica to which workers are or may be exposed
  • Protect workers from respirable crystalline silica exposures above the PEL
  • Use dust controls to protect workers from silica exposures above the PEL
  • Provide respirators to workers when dust controls cannot limit exposures to the PEL

Protective Actions

There are several steps you can take to protect your employees and your business:

  • Familiarize yourself with OSHA Table 1 and comply with its requirements whenever possible. Note that employers who fully and properly implement the practices specified in Table 1 are not required to measure respirable silica exposure for workers engaged in the Table 1 task.
  • If Table 1 compliance is not possible, but airborne silica levels may be high, refer to OSHA’s guidelines for measuring the amount of airborne silica. If levels exceed 50 µg/m3, use dust controls to protect employees. Dust controls include wetting down work operations, using local exhaust ventilation and enclosing airborne silica-producing operations. If dust controls cannot limit airborne silica exposure, provide respirators to employees.
  • Be wary of contractors or subcontractors who may not be compliant with the new regulations.

We will continue to monitor OSHA’s enforcement of silica exposure regulations to keep you informed of the best ways to comply while protecting your employees and your business. We also can assist with reviewing compliance measures and contract requirements.