Safety Report

New OSHA regulations outline ways to limit respirable crystalline silica


After many years of discussion and debate, OSHA has finally promulgated two new respirable

crystalline silica standards: one for construction, and the other for general industry and maritime. OSHA began enforcing most provisions of the standard for construction in September 2017, and will begin enforcing most provisions of the standard for general industry and maritime on June 23, 2018.


Crystalline silica is a common mineral found in construction materials such as sand, stone, concrete, brick and mortar. When workers cut, grind, drill or crush materials that contain crystalline silica, incredibly small dust particles are created. Activities such as abrasive blasting with sand; sawing brick or concrete; sanding or drilling into concrete walls; grinding mortar; manufacturing brick, concrete blocks, stone countertops or ceramic products; and cutting or crushing stone result in worker exposure to respirable crystalline silica dust. These tiny particles (known as “respirable” particles) — very small particles at least 100 times smaller than ordinary sand you might find on beaches and playgrounds — can travel deep into workers’ lungs and cause silicosis, an incurable and sometimes deadly lung disease. Respirable crystalline silica also causes lung cancer, other potentially debilitating respiratory diseases such as chronic obstructive pulmonary disease and kidney disease. In most cases, these diseases occur after years of exposure to respirable crystalline silica. About 2.3 million people in the U.S. are exposed to silica at work.

The construction standard (29 CFR 1926.1153) requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers. Employers can either use a control method, like ones laid out in Table 1 of the construction standard, or they can measure workers’ exposure to silica and independently decide which dust controls work best to limit exposures in their workplaces to the permissible exposure limit (PEL).

Table 1 matches 18 common construction tasks with effective dust control methods, such as using water to keep dust from getting into the air or using a vacuum dust collection system to capture dust. In some operations, respirators may also be needed. Employers who follow Table 1 correctly are not required to measure workers’ exposure to silica from those tasks and are not subject to the PEL. This is a significant benefit, because air monitoring programs in a construction environment can be quite costly, and it can be difficult to obtain accurate exposures.

Table 1 outlines engineering controls, work practices and what, if any, respiratory protection is required. The Assigned Protection Factor (APF) level for respiratory protection that a respirator is expected to meet is governed by the task being performed and the amount of time the task is performed.

Many contractors will be making investments to either upgrade or purchase new equipment and tools outlined in Table 1.


Table 1 Example

An example excerpt from Table 1 is shown below:

In this example of a handheld power saw, the tool with any blade diameter must be equipped with an integrated water delivery system (commercially developed specifically for the type of tool in use) that continuously feeds water to the blade. The water delivery system usually includes a nozzle for spraying water attached near the blade that is connected to a water basin via a hose and pump. The tool must be operated and maintained in accordance with manufacturer’s instructions to minimize dust emissions.

Handheld power saws equipped with an integrated water delivery system for blade cooling also suppress dusts and meet the requirements of Table 1. Full and proper implementation of water controls on handheld power saws requires the employer to ensure that:

  • An adequate supply of water for dust suppression is used,
  • The spray nozzle is working properly to apply water at the point of dust generation,
  • The spray nozzle is not clogged or damaged and
  • All hoses and connections are intact.

Table 1 does not specify a minimum flow rate; however, water must be applied at the flow rate specified by the manufacturer. When working with handheld power saws of any blade diameter, respiratory protection with a minimum APF of 10 is required for work done outdoors for more than four hours per shift and for work done indoors, or in an enclosed location, regardless of task duration. When using a handheld saw indoors or in enclosed spaces (areas where airborne dust can buildup, such as a structure with a roof and three walls), employers must provide additional exhaust, as needed to minimize the accumulation of visible airborne dust. See the section on Indoors or Enclosed Areas for more information.


Compliance specifics

Employers who do not fully implement the control methods on Table 1 must:

  • Determine the amount of silica that workers are exposed to if it is, or may reasonably be expected to be, at or above the action level of 25 μg/m3 (micrograms of silica per cubic meter of air), averaged over an 8-hour day;
  • Protect workers from respirable crystalline silica exposures above the PEL of 50 μg/m3, averaged over an eight-hour day;
  • Use dust controls and safer work methods to protect workers from silica exposures above the PEL; and
  • Provide respirators to workers when dust controls and safer work methods cannot limit exposures to the PEL.

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 identifies tasks that involve exposure and methods used to protect workers, including procedures to restrict access 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, such as use of compressed air without a ventilation system to capture the dust and dry sweeping, where effective, safe 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 the health effects of silica exposure, workplace tasks that can expose them to silica and ways to limit exposure; and
  • Keep records of workers’ silica exposure and medical exams.


Additional considerations

Because OSHA is concerned about subcontractors who might expose workers from other trades to the silica dust they generate this can saddle general contractors with the responsibility of ensuring all subcontractors are complying with the new standard. For example, electricians could be exposed to dust even though they don’t create it themselves through their operations.

Modified housekeeping will be important to control exposure to silica dust. Using HEPA vacuums or wet sweeping should be used instead of dry methods. And never allow workers to use compressed air to clean off surfaces or clothing unless a proper ventilation system is used to capture the dust.

Additional information on OSHA’s silica standard can be found at OSHA can provide compliance assistance through a variety of programs, including technical assistance about effective safety and health programs, workplace consultations, and training and education.

Employers can view the free Small Entity Compliance Guide from OSHA’s website at

Workers’ compensation insurance carriers are another good resource. And sample exposure control plans and templates can be downloaded from the internet.

Companies that are noncompliant with the standard will face a maximum fine of $12,675 for a serious or other-than-serious violation; $12,675 per day past the abatement date for a failure-to-abate violation, and $126,749 for a repeated or willful violation.


The Engagement Effect, a division of Ross Performance Group, LLC, offers solutions in organizational results, safety and health, leadership, talent management and culture change. Learn more about us at or email the author at