Crystalline Silica, The New Asbestos

Written by:  Rick Mulkey
President at Compliance Safety Solutions

Silica, present in concrete dust, is a hazardous material and is the focus of the new OSHA regulation 1926.1153.  This information is an overview of the new updated standard.  This regulation has a compliance date for general construction by September 23, 2017.  The new OSHA respirable crystalline silica dust regulation offers several options for compliance and we want to help you understand those options.

Under the existing silica rule established in 1971, employers were responsible for testing exposure and finding ways to limit exposure below ~250 μg/m3 averaged over an 8-hour workday.  The new standard aligned the permissible exposure limit (PEL) for the construction industry and general industry to the NIOSH recommended limit of 50 μg/m3averaged over an 8-hour workday (time weighted average, or “TWA”).  According to OSHA, the new PEL is expected to prevent hundreds of silica-related deaths and illnesses each year – including 900 new cases of silicosis.

Under the new OSHA construction standard, OSHA offers three methods an employer can choose from to demonstrate compliance and assess employee exposure.  An employer can choose from one of the three or any combination of the three to ensure their employees are protected.

The options are:

  1. Table 1: a table of pre-defined tasks and specified control methods available in the market today can be found the OSHA Standard 1926.1153.
  2. Performance or ‘Objective Data’: assess exposure by providing objective data proving the control method used reduces silica dust exposure below the permissible exposure level (50 μg/m3).  Accelerated silicosis: Results from exposure to higher levels of crystalline silica and occurs 5 to 10 years after exposure.  Acute silicosis: Can occur after only weeks or months of exposure to very high levels of crystalline silica. Death occurs within months.
  3. Scheduled Air Monitoring program: assess exposure by implementing a scheduled air monitoring program to ensure employees are not exposed above 50 μg/m3

Where is Silica found
The most common form of crystalline silica is quartz, which is found in sand, gravel, clay, granite, diatomaceous earth, and many other forms of rock.  Non-crystalline silica is found in glass, silicon carbide, and silicone.

What types of material contain Silica?
Silica is a natural substance found in materials on construction sites, such as concrete, bricks, rocks, stone, sand and clay.  Dust containing silica is created when these materials are cut, ground, drilled or otherwise disturbed.  If the silica particles in this dust are small enough (known as respirable crystalline silica it can be breathed deep into the lungs and cause damage.  The dust in your lungs (like asbestos) will not come out by coughing and will not dissipate, it is there perhaps forever.  The dust that can be breathed in is not always visible to the naked eye.

Tasks which may expose construction workers to silica dust include:  Sawing, hammering, sanding, drilling, grinding and chipping concrete or masonry (bricks, stone and fibre cement products).  Demolishing concrete and masonry structures.

Abrasive blasting of concrete and other materials (especially where sand is used as the abrasive).  Dry sweeping or the pressurised air blowing of concrete, concrete dust and rock.  Chipping, hammering and drilling rock.  Also the crushing, loading, hauling and dumping of rock are all activities that create dust that can be hazardous.

What does the standard require?
The standard requires employers to limit worker exposures to respirable crystalline silica and to take other steps to protect workers.

The standard provides flexible alternatives, especially useful for small employers.  Employers can either use a control method laid out in Table 1* of the construction standard 1926.1153 or they can measure workers’ exposure to silica and independently decide which dust controls work best to limit exposures to the PEL in their workplaces.

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 where feasible 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 work operations that result in silica exposure and ways to limit exposure.
  • Keep records of workers’ silica exposure and medical exams.

Important note: Lung disease can be caused by both long term exposure to small or moderate levels of silica dust, and short term exposure to high levels of silica dust.  It is also important to note that smoking adds to the lung damage caused by silica dust exposure.

What are employers’ responsibilities?
Employers have a legal duty to take all practicable steps to ensure employees are safe at work.  Exposure to silica dust is a workplace hazard that employers must eliminate, isolate or minimize.

As an employer, you should be able to recognize where work tasks may create silica dust.  You should then plan ahead to remove the dust or control any worker exposure.  Where silica dust is created on a worksite, you should implement: Dust control methods; Respiratory protection; Air monitoring; Health monitoring; Protective clothing; Warning signs and Employee Training.

This information is a brief overview.  Additional information including training methods and a “FREE” template of a Respirable Crystalline Silica written compliance safety program is available by contacting

Connect with Rick Mulkey on LinkedIn.

One comment

Leave a Reply