Exposure Assessment and Engineering Controls for Crystalline Silica

Exposure Assessment

Assessing worker exposure to respirable crystalline silica is important to determine the need for exposure controls and personal protective equipment. Prior to exposure monitoring, review each analytical method carefully and consult an American Industrial Hygiene Association (AIHA) accredited laboratory for analysis. An accredited laboratory can provide additional guidance about appropriate sampling methods.

The NIOSH Manual of Analytical Methods (NMAM) is a collection of methods for sampling and analyzing contaminants in workplace air. These methods have been developed or adapted by NIOSH or its partners and have been evaluated according to established experimental protocols and performance criteria. NMAM also includes chapters on quality assurance, sampling, and portable instrumentation.

  • NIOSH Method 7602 – Silica, Crystalline, by IR
    This method is recommended if there are minimal amounts of amorphous silica and silicates in the sample. There are potential interferences with this method that are difficult to identify without the help of an experienced geologist.
  • NIOSH Pocket Guide to Chemical Hazards
    The Pocket Guide is a source of general industrial hygiene information on several hundred chemicals/classes found in the work environment. Key data provided for each chemical/substance includes name (including synonyms/trade names), structure/formula, CAS/RTECS Numbers, DOT ID, conversion factors, exposure limits, IDLH, chemical and physical properties, measurement methods, personal protection, respirator recommendations, symptoms, and first aid.

Other Methods

Engineering Controls

A wet blade sawing through a concrete slab

Photo by Getty Images

Engineering controls are interventions that can be used to eliminate or more safely work around hazards. Incorporating engineering controls are beneficial because they reduce work-related injuries and illness. This is done by removing or minimizing hazardous conditions such as respirable dust or excessive noise. To control silica exposures, there are wet methods that use water sprays to control dust. There are also dry methods like ventilation controls that use vacuums and high efficiency particulate air (HEPA) filters to control dust.

Concrete Grinder
Cut-off Saw

NIOSH Engineering Controls Database

The NIOSH Engineering Controls Database contains information on engineering control technology. The database content is summarized from previously published NIOSH research. This research was originally published as Engineering and Physical Hazard Reports, workplace solutions, and trade and journal articles. If the data was summarized from an Engineering and Physical Hazard Report, there will be a report number in the summary. If there is a pdf icon next to the number, clicking on the icon will open the original report.

Directory of Engineering Controls

NIOSH directory page providing links to engineering control-related webpages, projects, programs, tools, and resources to improve workplace health and safety.


NIOSH Research and Selected Publications

NIOSH studies health effects of silica exposures in workers and exposure prevention through engineering controls in several different industries. These include mining, construction, oil and gas, stone countertop, manufacturing, and dentistry. The list of publications below provides recent studies conducted by NIOSH.

Search “silica” on NIOSHTIC-2 for additional NIOSH silica research publications.