Construction employers are now subject to OSHA’s Respirable Crystalline Silica rule, which became enforceable on September 23, 2017. OSHA published a guidance memorandum dated September 20, 2017, which set forth a 30-day “grace period”, ending October 23, 2017. During this “grace period”, OSHA has indicated that it will exercise enforcement discretion against employers that are making good faith efforts to comply with the new construction silica standard. OSHA is offering compliance assistance and outreach to employers during this time period. Moreover, OSHA has stated it will issue new interim inspection and citation guidance prior to October 23, 2017. OSHA’s memorandum signals that it recognizes that the new standard is complex and will take time for the regulated industry to understand and implement it.

Summary of Construction Exposure Silica Requirements

The new standard establishes an 8-hour time-weighted average (TWA) Permissible Exposure Limit (PEL) of 50 µg/m3 (previous limit was 350 ug/m3), an action level (AL) of 25 µg/m3, and a host of ancillary requirements. OSHA enforces PELs for many types of substances including silica.

The silica rule sets forth two alternative means by which regulated employers can comply. First, employers may implement engineering controls, work practices, and respiratory protection specific to the regulated task or equipment as set forth in the regulation. Table 1 contained in 29 CFR 1926.1153 sets forth 18 types of equipment and/or tasks that must be individually considered, such as jack hammers, drills, saws, grinders, etc.

Alternatively, employers may elect to assess and limit their employees’ exposure to respirable crystalline silica, which requires regulated employers to ensure that no employee is exposed to respirable crystalline silica above 50 µg/m3. This includes assessing and monitoring employee exposures for employees who are or may reasonably be expected to be exposed at or above the AL. Additional periodic monitoring may be required if the most recent exposure monitoring shows employee exposures are above the AL. Reassessments may also be triggered by changes in production, equipment, control equipment, personnel, or work practices, or otherwise if the employer has “any reason to believe that new or additional exposures at or above the action level have occurred.” Following the alternative monitoring approach triggers additional requirements relating to notification to employees and recordkeeping. See 29 CFR 1926.1153(d).

Lastly, the new regulations set forth requirements that apply to all regulated construction employers. These requirements include development of a written exposure control plan, the provision of medical surveillance for employees who are required to use a respirator for 30 or more days per year, housekeeping, employee information and training, and recordkeeping. See 29 CFR 1926.1153(g), (h), (i), (j).

OSHA’s 30-Day “Outreach” Period Could Include Inspections That May Result in Citations to Employers Who Have Not Attempted to Comply with the Regulations

Now that the new construction standard is effective, OSHA will begin inspecting job sites and evaluating whether regulated employers are complying with the new requirements. In the first thirty days through October 23, 2017, if OSHA discovers any condition that it considers to be a violation, OSHA is more likely to issue a citation to an employer if the employer has not yet made any efforts to comply. Further, OSHA’s recent memorandum states that OSHA will collect exposure air monitoring and consider such monitoring results in its decision regarding whether to issue a citation. Presumably in an effort to ensure some degree of uniform application and enforcement consistency across the country, proposed citations issued through October 23, 2017, will require OSHA National Office review.

Additional Industries Will Be Subject to Enforceable Silica Rules in 2018

OSHA has scheduled compliance deadlines of the silica rule for General Industry and Maritime to be effective June 23, 2018 (two years after the Final Rule effective date). The Hydraulic Fracturing industry will also become subject to the enforceable silica rule on June 23, 2018, for all requirements except Engineering Controls. The Hydraulic Fracturing engineering controls requirements will become enforceable June 23, 2021. We encourage all regulated employers to consider the requirements and to begin developing compliance plans in advance of the relevant compliance deadlines.

Additional Background on Crystalline Silica

Crystalline silica is contained in sand, granite, and other minerals, and the most common form is quartz, according to OSHA. Crystalline silica may present an exposure risk to employees when workers drill, grind, or otherwise break down materials containing crystalline silica, as these activities can cause the particles to become respirable size, similar to dust, and airborne. OSHA’s Final Rule estimates the silica rule will protect the nearly 2.3 million workers who are exposed to silica, prevent more than 900 new cases of silicosis per year, and provide annual net benefits of $7.7 billion.


OSHA’s Respirable Crystalline Silica construction standard is codified at 29 CFR 1926.1153, and it is available on the OSHA website here. OSHA’s memorandum dated September 20, 2017 is available on the OSHA website here.