History

The health risks associated with exposure to dust containing crystalline silica are well documented. In 1700, Dr. Bernardino Ramazzini, considered the founder of occupational medicine, identified evidence of silicosis in stone cutters. Roughly 200 years later, Dr. Alice Hamilton, a physician whose work resulted in significant safety and health reforms, documented silica-related illnesses among granite workers. In the early 1900s, granite cutters in Vermont recognized the connection between the dust they were inhaling and the resulting fatal illnesses. By the 1930s they had successfully bargained for the installation of ventilation equipment in their work sheds.

Unfortunately, workers in other industries and parts of the country were still at risk. In the early 1930s, the Gauley Bridge tunnel project became the site of one of the worst industrial disasters in U.S. history. Hundreds of workers died from silicosis while building the tunnel, and another 1,500 were reported to have contracted the disease within two years of working on the project. This disaster prompted a Congressional call to action. Watch the video below to hear from the workers and elected officials to learn more.

The federal government responded and in 1938 the Secretary of Labor, Francis Perkins, held a National Silicosis Conference and initiated a campaign to “Stop Silicosis,” stating: “Our job is one of applying techniques and principles to every known silica dust hazard in American industry. We know the methods of control – let us put them in practice.” Watch the video below to learn more about the campaign.

Despite these efforts, silica exposure continued to be a serious health hazard for workers in the construction industry. As new products, tools, and work practices were introduced, new means of exposure were created. An article in a leading construction trade magazine summed up the situation: “With the advent and increased use of dry cutting, drilling, and grinding of concrete and masonry materials in construction, we often see workers operating in a cloud of dust with no respiratory protection or safety measures to prevent airborne dust. Exposure levels in settings like construction sites are highly variable for airborne silica dust, which poses a significant risk to workers.”[*]

In 1996, the Secretary of Labor began a new campaign to raise awareness and encourage safer work practices called “It’s Not Just Dust,” and initiated a Special Emphasis Program (SEP) on Silicosis to provide guidance to “reduce and eliminate the workplace incidence of silicosis from exposure to crystalline silica.” In addition, OSHA, NIOSH, and the American Lung Association held a conference titled “The Campaign to End Silicosis.”

Watch excerpts from the 1996 conference to learn more from the leadership at that time:

• Secretary of Labor, Robert Reich
• Assistant Secretary for OSHA, Joe Dear
• President of the American Lung Association, Dr, Alfred Munzer
• Director of NIOSH, Dr. Linda Rosenstock

The 1996 conference and SEP raised awareness of the hazard and prompted several stakeholder groups, as well as safety and health professionals, to call on OSHA to develop and implement a comprehensive silica standard for the construction industry. OSHA responded by adding silica to its regulatory agenda, drafting a silica standard, and conducting a small business review as required by the Small Business Regulatory Enforcement Act (SBREFA).

In February 2011, more than 70 years after the Gauley Dam disaster and roughly 15 years after the initiation of the SEP on silica, OSHA sent a draft standard to the Office of Management and Budget (OMB) for review before publishing the standard for public comment, as required under Executive Order 12866. Under this order, the OMB’s focus is to review “economically significant” rules, and the review must be completed within 120 days.

On April 19, 2012, the Committee on Health, Education, Labor & Pensions held a full committee hearing – “Time Takes Its Toll: Delays in OSHA’s Standard Setting Process and the Impact on Worker Safety,” which addressed delays in the regulatory process. Witnesses included Tom Ward, a member of the International Union of Bricklayers and Allied Craftworkers from Local 1 Michigan, who testified about the loss of his father to silicosis and concerns about continued worker exposures today. Click here to read Mr. Ward’s statement. To learn more: watch the video of the hearing or read all of the testimony.

On August 23, 2013, after more than two years, the OMB released the proposed silica standard back to OSHA. OSHA issued a press release announcing a proposed rule aimed at curbing lung cancer, silicosis, chronic obstructive pulmonary disease, and kidney disease in America’s workers. The proposal sought to lower worker exposure to crystalline silica, which kills hundreds of workers and sickens thousands more each year.  

On March 24, 2016, OSHA announced the final rule to protect workers from exposure to respirable crystalline silica.  Shortly thereafter, construction and other industry groups challenged the standard in court, and on December 22, 2017, the U.S. Court of Appeals for the District of Columbia rejected the challenge and upheld the standard.

Enforcement of the construction standard began September 23, 2017 and enforcement of the general industry and maritime standard began on June 23, 2018 with two exceptions: (1) employers were given until June 23, 2020 to begin offering medical surveillance to employees who would be exposed at or above the action level for 30 or more days a year; (2) Hydraulic fracturing operations in the oil and gas industry were given until June 23, 2021 to begin implementing dust controls to limit exposures to the new PEL.

Although the silica standard took 19 years to go through the rulemaking process, every Labor Secretary between 1996 and when the standard was finalized and implemented – under both Republican and Democratic Administrations – kept controlling silica dust and protecting workers a regulatory priority.

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_{[*] Masonry Magazine, “The Big Deal About Silica Dust Collection,” by Brian Delahaut vice president of MK Diamond Products, Inc., December 2009.}

Timeline

The following is a brief chronology of silica-related regulatory efforts since the early 1990s:

• February 5, 2025 – Cal/OSHA made permanent the temporary standard issued in December 2023 to protect workers in general industry engaged in dust-generating tasks involving artificial stone and natural stone.
• September 25, 2023 – The U.S. Department of Labor announced the launch of a new OSHA enforcement initiative, which began on September 22, 2023, to protect workers from silica exposure in engineered stone fabrication and installation industries. 
• August 15, 2019 – OSHA released a request for information and comment on Table 1 of the agency’s Respirable Crystalline Silica Standard for Construction. 
• June 23, 2018 – OSHA began enforcement of the Respirable Crystalline Silica Standard for General Industry and Maritime, except for the following:
  • Medical surveillance of employees who would be exposed at or above the action level for 30 or more days a year started on June 23, 2020. 
  • For hydraulic fracturing operations in the oil and gas industry, implementation of dust controls to limit exposures to the new PEL began June 23, 2021.
• December 22, 2017 – The U.S. Court of Appeals for the District of Columbia upheld the standard and rejected the challenge brought by industry groups.
• September 23, 2017 – OSHA began enforcing the respirable crystalline silica standard for the construction industry.
• September 20, 2017 – OSHA released a memo – stating for the first 30 days of enforcement OSHA will carefully evaluate good faith efforts taken by employers in their attempts to meet the new construction silica standard. OSHA will render compliance assistance and outreach to ensure that covered employers are fully and properly complying with its requirements.
• April 6, 2017 – OSHA delayed enforcing crystalline silica standard in construction from June 23, 2017 to September 23, 2017.
• April – June, 2016 – Industry groups challenged the standard.
• March 24, 2016  – OSHA announced the final rule to protect workers from exposure to respirable crystalline silica. Read the press release, and watch the video “Stop Silicosis (2016)” . On March 25, 2016, the final rule was published. For an in-depth explanation of the standard, including the risk assessment, economic and technical feasibility analysis and health effects, see the preamble published in the Federal Register.
• March 21, 2016 – The OMB concluded their review of the final silica standard.
• December 21, 2015 – OSHA submitted the final silica standard to the OMB for review under Executive Order 12866.
• December 18, 2015 – OSHA announced plans to send the final silica rule to the White House Office of Management and Budget by Christmas.
• November 20, 2015 – OSHA announced in its regulatory agenda that the final rule on silica is expected to be released in February 2016.
• June 17, 2014 – OSHA announced a 31-day extension for submitting final briefs, arguments, and summations on the proposed standard to August 18, 2014. All submissions available at on Regulations.gov – Rulemaking Docket.
• April 4, 2014 – OSHA concluded 14 days of public hearings on the proposed standard.  Members of the public who filed a timely written notice of intention to appear prior to the hearings were able submit additional comments. 
• March 18 – April 4, 2014 – OSHA held three weeks of public hearings where labor advocates, health experts, and industry groups testified on the proposed standard. This was followed by two and a half months for public submission of post-hearing comments.
• January 24, 2014 – OSHA extended the comment period on the proposed silica rule for an additional 15 days to February 11, 2014. Public hearings on the proposed rule were rescheduled to begin on March 18, 2014.
• January 14, 2014 – OSHA held a live web chat on the proposed silica rule. 
• 2014 – 2015 – OSHA reviewed the testimony, comments and record evidence submitted by the public, drafted the final standard, and prepared the final economic and regulatory analysis.
• October 25, 2013 –  OSHA extended the comment period on the proposed silica rule by 47 days to provide additional time for public input.
• September 27, 2013 – Construction Industry Safety Coalition, which represents several construction trade associations and their members, submitted a request to OSHA to extend the comment period 90-days to March 11, 2014.
• September 20, 2013 – OSHA made a presentation: “Occupational Exposure to Respirable Silica“; on the proposed standard for the small business roundtable.
• September 12, 2013 – OSHA published a Notice of Proposed Rulemaking for respirable crystalline silica in the Federal Register – Notice: Occupational Exposure to Respirable Crystalline Silica.
• August 23, 2013 – U.S. Department of Labor’s OSHA announced a proposed rule to protect workers exposed to crystalline silica after the OMB concluded their review – see the press release.
• July 3, 2013– Silica is listed on OSHA’s Regulatory Agenda indicating that the proposed rule will be released in July 2013.
• June 5, 2013– A group of Senate and House Democrats sent a letter urging OMB’s Director to take “prompt action” to expedite the rulemaking process on silica and other pending issues noting: “Delays exceeding 90 days include … the Occupational Safety and Health Administration’s (OSHA)  proposed rule to protect workers from cancer-causing silica dust. OSHA’s preliminary analysis indicates that the silica rule would prevent approximately 60 deaths per year from lung cancer and silicosis…”
• May 7, 2013 – The Chairman of The Judiciary Subcommittee On Oversight, Federal Rights, and Agency Action sent a letter to the OMB “urging the federal agency to end serious delays in reviewing proposed regulations and guidelines intended to protect workers from inhaling silica dust…”
• March 12 and 18, 2013 – The OMB review continued. March 2013, OMB held its first meetings in 19 months on silica. 
• February 27, 2013 – Top Democratic lawmakers on the House and Senate worker panels sent a letter to the OMB urging release of the proposed OSHA silica standard.
• April 19, 2012 – the Committee on Health, Education, Labor & Pensions held a full committee hearing – “Time Takes Its Toll: Delays in OSHA’s Standard Setting Process and the Impact on Worker Safety”.
• February 14, 2011 – OSHA submitted a draft proposed silica standard to the OMB for review under Executive Order 12866. The OMB review was required to be completed within 120 days.
• 2009 IARC reaffirmed its position on silica as a carcinogen.
• September 2008 – Cal/OSHA issued a standard: “Control of Employee Exposures from Dust-Generating Operations Conducted on Concrete or Masonry Materials”.
• December 2004 – New Jersey’s governor signed a law that prohibits the dry cutting and dry grinding of masonry.
• December 2003 – OSHA submitted a draft silica standard to a Small Business Regulatory Fairness Enforcement Act (SBREFA) panel for review.
• October/November 2000 – OSHA held Stakeholders’ Meetings on silica.
• June/July/ September 1999 – OSHA held Stakeholders’ Meetings on silica.
• October 1998 – OSHA’s Advisory Committee on Construction Safety and Health (ACCSH) formed a Silica Work Group.
• 1997 – The first time silica is listed on OSHA’s Regulatory Agenda. Silica continued to be listed as a priority in subsequent years.
• May 1996 – OSHA created a Special Emphasis Program to Prevent Silica Exposure.
• 1996 – The World Health Organization – International Agency on Cancer Research (IARC) first classified silica as a known human carcinogen.
• 1994 and 1995 – OSHA listed silica as a priority for rulemaking.

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Selected articles and press releases on the development of the standard can be found here.