Silica Exposure Standard Frequently Asked Questions (FAQ)

Background and Health Impacts

What is crystalline silica?

Crystalline silica is a mineral used for many industrial applications and products. It is widely used at construction sites. It is used to make materials such as sand, stone, concrete and mortar, which in turn are used to produce products like glass and ceramic. Silica exposure occurs from industrial operations like foundry work or fracking.

How can exposure impact your workers’ health?

Crystalline silica is linked to several diseases. These include silicosis (an incurable lung disease), kidney disease, chronic obstructive pulmonary disorder (COPD) and lung cancer. Inhaling even a small amount of crystalline silica particles drastically increases the risk of developing serious health issues.

Who is at risk from exposure?

About 2.3 million workers are exposed to crystalline silica while on the job. Just being around sand, or other silica-laced materials however, is not dangerous. Inhalation occurs with specific job applications that release breathable dust into the air. These “respirable” crystalline silica particles are 100x smaller than than ordinary grains of sand found on playgrounds or beaches and are made from high-energy applications like sawing, cutting, grinding, crushing, or drilling on substrates like stone, concrete, mortar, or brick.

What is the connection between crystalline silica and lung cancer?

Scientific data has linked crystalline silica and lung cancer. Both the World Health Organization (WHO) and the National Institute of Health’s (NIH) Toxicology Program have classified crystalline silica as a ‘known human carcinogen’. OSHA has reviewed more than 50 studies providing evidence of this link. It has found evidence between the two in at least ten different industries, prompting the American Cancer Society (ACS) to use the same classification as WHO and NIH.

How will the new rule protect workers’ health?

Employers are now required to utilize engineering controls like ventilation and wet methods for sawing and/or cutting crystalline silica-containing materials. OSHA expects these measures to prevent up to 600 deaths per year from silica-related diseases like lung cancer, silicosis and kidney disease. The measures are meant to prevent more than 900 new cases of silicosis every year.

Why is a new crystalline silica rule being issued?

The current permissible exposure limit (PELs) for crystalline silica was established 45 years ago and has not been updated to reflect recent scientific research regarding exposure to crystalline silica and diseases like lung cancer and silicosis. Crystalline silica is classified as a ‘human carcinogen’ by groups like the National Institute for Occupational Safety and Health (NIOSH), the U.S. National Toxicology Program and the International Agency for Research on Cancer. Previous PELs were measured with methods that are no longer in use and that failed to measure the true impact of crystalline silica on workers’ health.

With evidence of a decline in silicosis cases in the United States, is this new rule necessary for preventing industrial exposure to crystalline silica?

More workers in 2014 died from silicosis than from fires or industrial accidents like structural or trench collapses. Most deaths from silicosis are never diagnosed or even reported and those numbers reported between 2005 and 2014 do not include deaths from silica-related ailments like lung disease, kidney disease or COPD. This has prompted lawmakers to take action by implementing this new rule across industries, including newer industries like hydraulic fracking.

What is the new permissible exposure limit (PEL)?

The new PEL limits worker exposure to breathable crystalline silica to 50micrograms/cubic meter of air (μg/m3) over a span of eight hours. OSHA determined the new PEL of 50 μg/m3 was enough to significantly reduce the risk of developing crystalline silica-related diseases in workplace environments, although the American Conference of Governmental Industrial Hygienists recommends a lower exposure limit of 25 μg/m3 over an eight-hour day.

Impact on Industry

A number of major industries will be affected by this new change. These include, but are not limited to:

  • Construction
  • Ready-Mix Concrete
  • Glass Manufacturing
  • Concrete products
  • Stone products
  • Pottery products
  • Abrasive blasting for general industry, construction and maritime work
  • Structural clay products
  • Foundries
  • Dental laboratories
  • Refractory furnace installation/repair
  • Paintings/coatings
  • Jewelry production
  • Railroads
  • Hydraulic fracturing for gas/oil
  • Landscaping
  • Asphalt products manufacturing

How many workplaces will be affected?

There are approximately 676,000 workplaces in general industry, construction and maritime applications that will be affected by the new rule.

How many workers will be impacted?

An estimated 2.3 million workers are exposed to breathable crystalline silica every year. About 2 million of those cases are within the construction industry. At least a million of these exposure cases are expected to be resolved with the new mandates.

What will be the economic impact?

The total annual cost of implementing the new rule is $1 billion. The rule is expected to provide an average annual net benefit of $3.8 million over the next 60 years. This should result in annual costs of roughly $1,524 for the average workplace. However, OSHA’s research indicates that the economic impact on small businesses will be minor, with only a $560 average for businesses with less than 20 employees.

Why does the total compliance cost appear to be so high?

OSHA’s standards for general industry and construction are extremely broad. As many as 2.3 million workers and 676,000 establishments maybe affected. According to a recent economic analysis conducted by OSHA, the new rule will not have a substantial economic impact on large firms. Instead, the aggregate costs will be sufficiently offset by benefits like reduced costs associated with treating and preventing silica-related deaths or illnesses.

How will jobs be impacted?

Inforum, a renowned macroeconomics modeling firm based at the University of Maryland, recently conducted a study that showed the new rule will have a negligible, yet positive net effect on the overall employment rate in the United States.

How have small businesses been included in the new rule?

A Small Business Advocacy Review Panel was convened before the silica rule was proposed. Following the proposal, small business owners and members of the general public were given the chance to voice concerns about writing the new rule. Suggestions were submitted by testimony at a public hearing, written comments and submission of data and briefs following the hearing. OSHA then utilized all of the information to decide upon the final rule and began evaluating its impact on small businesses.

Rule Requirements

How can silica exposure be controlled in order to abide by the PEL?

Engineering controls such as ventilation must be used by employers to keep exposure to breathable crystalline silica at, or below the PEL. Wetting down surface dust before sweeping, or using the water flow rate the manufacturer recommends for a tool with water control features are other effective ways to minimize the risk of exposure to crystalline silica. Process isolation has been known to work well. Respirators are effective but they are only allowed when workplace and engineering practice controls cannot keep exposure levels at or below the PEL.

Why can’t workers just wear respirators at all times?

Respirators are neither practical or effective in providing enough protection against breathable crystalline silica. Unless they are individually fitted and regularly maintained for each worker, there will still be a much higher risk of exposure compared with facilities utilizing vents or other control methods. Respirators are less reliable simply because it is up to the individual workers to ensure their devices are being properly fitted and maintained and are worn consistently and correctly, despite the potential for discomfort, particularly in hot weather.

Are air sampling methods used to detect and measure silica reliable?

Yes and to improve on the reliability of these measurements, employers must have their silica samples analyzed by qualified laboratories that utilize methods specified in Appendix A of the standard. These methods that have been published by OSHA, NIOSH and MSHA are incredibly precise.

Why must construction employers implement engineering and work practice controls a year before laboratories are required to meet specifications for air sample analysis?

Construction companies will not be required to conduct regular assessments for exposure. Those that do not use specific guidelines will, however, have sufficient measurements available from the one of the 40 laboratories in the United States.

What is the purpose of medical surveillance?

Identify negative health effects that are linked with crystalline silica exposure.
Determine if any employees are suffering from conditions including lung disease that may make them more sensitive to breathable crystalline silica exposure.
Determine the employee’s unique fit for a respirator.

Why are medical surveillance results given only to the workers and not their employers?

Employers are not provided with such information, a) because of patient confidentiality and b) because they are supposed to provide protection for employees based on silica exposure levels and how well the current controls are working. Employee physicians or licensed health care professionals instead provide recommendations to the employer based on the health of the patient(s).

Compliance Dates

When must employers comply with the standard for general industry and

Aside from hydraulic fracturing operations in the gas and oil industry, employers must:

  • Comply with all obligations of the standard (excluding the action level trigger for medical surveillance) by June 23, 2018.
  • Offer medical exams for employees exposed at or above PEL for 30 days or more a year by June 23, 2018.
  • Offer medical exams to employees exposed at or above the action level for 30 days or more a year beginning on June 23, 2018.

For hydraulic fracturing operations in oil and gas, employers must:

  • Comply with all obligations of the standard, except for engineering controls and the action level trigger for medical surveillance, by June 23, 2018.
  • Comply with requirements for engineering controls to limit exposures to the new PEL by June 23, 2021; employers can continue to have employees wear respirators if their exposures exceed the PEL between June 23, 2018 through June 23, 2021.
  • Offer medical examinations to employees exposed above the PEL for 30 or more days beginning on June 23, 2018.
  • Offer medical examinations to employees exposed at or above the action level for 30 or more days a year beginning on June 23, 2020.

Why is there a difference in these compliance dates?

The new rule allows hydraulic fracturing employers additional time to have these changes implemented and to take advantage of emerging technologies because the controls for breathable crystalline silica in this industry are still in development. These employers do not have to implement engineering controls until June 2021. Hydraulic fracturing employers may continue to provide individual respirators for their employees between June 2018 and June 2021 when exposures exceed the PEL.

When must employers comply with the construction standard?

Employers must comply with all of the obligations of the standard by June 23, 2017, with the exception of methods of sample analysis, which must be in compliance by June 23, 2018.

State Plans and Compliance Assistance

Will states with OSHA-approved programs adopt the standard?

States with OSHA-approved state plans will have six months to adopt and comply with the standards that are as effective as Federal OSHA standards. Some state plans may have more stringent requirements.

What resources are available for small businesses and other employers to help them comply with the standards?

OSHA offers extensive compliance assistance with Compliance Assistance Specialists, as well as on its website, in publications, webinars and through training programs. Many of these are designed to help small- to mid-sized employers. OSHA will develop a Small Entity Compliance Guide for crystalline silica to provide more information and assistance with the process.

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