OSHA’s new silica rule has been a hot topic for the past couple of years and finally went into full effect for general industry and maritime on June 23, 2018.

Any new rule can cause a fair amount of confusion (and industry turmoil), but the silica regulation was designed to be easy to comply with — all it takes is familiarizing yourself with the ins and outs of the rule.

Looking for details on silica regulation compliance for construction? Head to “Compliance Made Easy: What the Construction Industry Needs to Know About the New Silica Rule

The rundown on silica  

Silica, or silicon dioxide, is classified as a human lung carcinogen. It comes in two forms: crystalline and non-crystalline. The rule focuses on crystalline silica.

Where silica is found

Silica can be found virtually everywhere. In fact, it’s the second most abundant element in the Earth’s crust after oxygen. Quartz is the most common form of crystalline silica, but silica is also a primary component of rock, soil, and granite.

In the workplace, silica-containing materials are often just a stone’s throw away.

  • Asphalt paving material
  • Asphalt roofing material
  • Brick
  • Cement
  • Concrete
  • Concrete roof tile
  • Concrete block
  • Drywall
  • Fiber cement products
  • Granite
  • Grout
  • Gunite and shotcrete
  • Limestone
  • Mineral wool
  • Mortar
  • Paints and coatings
  • Plaster
  • Porcelain enameling
  • Quartzite
  • Refractory mortar and castables
  • Rock
  • Sand
  • Sandstone
  • Shale
  • Slate
  • Soil (fill dirt, topsoil, soil with fly ash added)
  • Stone
  • Structural clay
  • Stucco/EIFS
  • Terrazzo
  • Tile (clay and ceramic)


Risky industries

Since so many everyday materials contain silica, millions of U.S. workers are at risk, including about 320,000 workers in general industries and maritime.

  • Glass manufacturing  
  • Pottery products  
  • Structural clay products  
  • Concrete products  
  • Foundries  
  • Dental laboratories  
  • Paintings and coatings  
  • Jewelry production  
  • Refractory products  
  • Landscaping  
  • Ready-mix concrete  
  • Cut stone and stone products
  • Abrasive blasting  
  • Refractory furnace installation and repair  
  • Railroads  
  • Hydraulic fracturing for gas and oil  
  • Asphalt products manufacturing


When silica becomes dangerous

Silica alone isn’t dangerous. The hazard presents itself when silica-containing materials are cut, chipped, blasted, drilled, ground, or otherwise disturbed, producing a fine dust small containing particles small enough to breathe in. If you’re thinking, “that sounds a lot like asbestos,” you’re right.

Inhaling silica dust can contribute to a number of serious, and sometimes fatal, diseases:

  • Lung cancer
  • Chronic obstructive pulmonary disease (COPD)
  • Kidney disease
  • Silicosis


With silicosis, your lungs become scarred, causing labored breathing that worsens over time. There are three different types of silicosis: chronic, accelerated, and acute.  

  • Chronic
    • Latency period of 10-20 years after moderate to low exposure to respirable crystalline silica.
    • Symptoms include shortness of breath, and in later stages, fatigue, extreme shortness of breath, chest pain, or respiratory failure.
  • Accelerated
    • Latency period of 5-10 years after high exposure to respirable crystalline silica.
    • Symptoms include severe shortness of breath, weakness, and weight loss.
  • Acute
    • Latency period of a few months to two years after extremely high exposure to respirable crystalline silica.
    • Symptoms include severe disabling shortness of breath, weakness, and weight loss. Acute silicosis is often fatal.

Most reported cases of silicosis are chronic, and each year, about 100 people die from the disease. Aside from the primary symptoms of silicosis, reduced lung function can make you more susceptible to other serious illnesses such as tuberculosis.

OSHA’s new silica rule

Regulating respirable silica exposure is nothing new for OSHA. Experts have known about the adverse health effects of breathing in silica dust for 80+ years, and an exposure limit has existed for more than 40. However, the rule was created based on research conducted in the 1960s, so an update was well overdue.

The new PEL for silica

The updated silica rule essentially halved the original PEL for general industry. Exposure is now capped at 50 micrograms of respirable crystalline silica per cubic meter of air (50 μg/m3) averaged over an eight-hour day. Once the rule is in full effect for all industries (including construction and fracking), OSHA estimates it’ll save more than 600 lives and prevent about 900 new cases of silicosis every year.

Requirements of the new rule

Determine if workers are exposed over the action level.

OSHA defines action level as “a concentration designated in 29 CFR part 1910 for a specific substance, calculated as an eight (8)-hour time-weighted average, which initiates certain required activities such as exposure monitoring and medical surveillance.“

In the case of silica, employers are required to determine workers’ silica exposure if it is, or may reasonably expected to be, at or above the action level of 25 μg/m3 averaged over an 8-hour day. It sounds cryptic. But the general rule of thumb is if your employees are surrounded in a cloud of dust while working with silica-containing materials, they’re most likely exposed above the action level.

Limit access to regulated areas.

Employers are required to mark areas where workers could be exposed to the new PEL. There are three categories of people who can enter the regulated area:

  • Workers who have been authorized by the employer whose work duties require them to be in the regulated area
  • A person exercising the right to observe silica exposure monitoring procedures
  • A person authorized by the Occupational Safety and Health Act (or regulations issued under it) to be in a regulated area

You can use tape, cones, or other barricades to mark off regulated areas. Signs that say the following must be posted at each entrance:








Anyone who enters the regulated area must wear a respirator.

Implement work practice and engineering controls.

Employers are required to implement work practice and engineering controls to protect workers from being exposed to silica dust concentrations above the PEL.

Engineering controls include:

  • Dust suppression — applying water on an area before performing tasks that create dust (drilling, cutting, blasting, etc.)
  • Local exhaust ventilation — removing silica dust at or near the point where it is created
  • Enclosures — isolating the work process or the worker (also called “process isolation”)

Work practice controls include:

  • Wet sweeping — wetting down dust before sweeping it up
  • Following manufacturer’s recommendations — use the water flow rate recommended by the manufacturer if working with tools with water controls
  • Proper housekeeping — using HEPA-filtered vacuums

If, after implementing these work practice and engineering controls, it’s possible that employees are still exposed above the PEL, you’re required to reduce exposure as much as possible and also provide respiratory protection.

Restrict certain housekeeping practices.

The new silica rule also restricts specific housekeeping practices that kick up silica dust and increase worker exposure.

These housekeeping methods are prohibited under the new rule unless approved methods aren’t feasible:

  • Dry brushing
  • Dry sweeping
  • Compressed air

Provide respirators.

Respirators are your last line of defense against occupational hazards. Engineering and work practice controls are much more effective means of reducing exposure to silica dust.

That said, respirators are still critical to keeping your workers safe from the hazardous dust. The silica rule requires respiratory protection to be worn in the following situations:

  • When workers are exposed to silica dust levels above the PEL during installation or implementation of engineering and work practice controls.
  • When workers are exposed to silica dust levels over the PEL during work tasks where engineering and work practice controls aren’t feasible.  
  • When workers are exposed to silica dust levels above the PEL during work tasks where all feasible engineering and work practice controls are in place, but fall short of reducing exposure to an acceptable level.  
  • When workers enter a regulated area.  

When using respirators, you need to have a written respiratory protection program in place.

Establish and implement a written exposure control plan (ECP).

A written exposure control plan is key for getting everyone in your organization be on the same page when it comes to reducing exposure to silica dust, and is a requirement under the new rule.

Your ECP must describe the following the following:

  • All work tasks that expose your workers to silica dust
  • Engineering controls, work practices, and respiratory protection used to limit employee exposure for each task
  • Housekeeping strategies used to limit exposure to and clean up silica dust

You’re required to review the effectiveness of your silica dust ECP on an annual basis, making edits where necessary.

Offer medical exams

Any worker exposed over the action level of 25 μg/m3 averaged over an 8-hour day for 30 days per year is required to be under medical surveillance. Employees shall not be charged for any medical testing deemed necessary by exposure to silica dust on the job.

The purpose of medical surveillance is threefold:

  • To identify adverse health effects associated with exposure to silica dust so all parties can take appropriate action
  • To determine if an employee has a condition (e.g., lung disease) that might make them more sensitive to silica dust  
  • To determine if the worker is fit to use respirators when necessary  

Affected employees must receive medical exams every three years. Each medical assessment includes:

  • Full medical and work history
    • Past, present, and anticipated exposure to respirable crystalline silica and other workplace hazards that damage the respiratory system
    • Signs of respiratory system dysfunction
    • History of tuberculosis
    • Smoking status and history
  • Physical exam, playing close attention to the respiratory system
  • Chest X-ray
  • Pulmonary function test
  • Test for latent tuberculosis infection

Train workers

Safety training is one of the most powerful tools to protect workers on the job. As such, employers are required to get employees up to speed on all things silica. At the very least, every worker who is exposed to silica dust on the job should be able to answer the following questions:

  1. What are the health hazards associated with exposure to respirable crystalline silica?
  2. Which of your work tasks could result in exposure to respirable crystalline silica? How can you reduce your exposure while doing those tasks?
  3. What measures has your employer implemented, including engineering controls, work practices, and respirators, to protect you from exposure to respirable crystalline silica?
  4. What is the purpose of your medical examinations? (if applicable)
  5. What is included in medical examinations covered under the silica rule?

Keep records

All of the efforts that have been outlined so far would be all for naught if you didn’t keep detailed records. As such, the new silica rule requires that you keep records of:

  • Air monitoring data (exposure level measurements)
  • Objective data you rely on to ensure compliance with the new rule
  • Medical surveillance records

Compliance dates for the new silica rule: general industry, maritime, and hydraulic fracturing

General Industry and Maritime (Other than Hydraulic Fracturing Operations in the Oil and Gas Industry)

Comply with all obligations of the standard, except the action level trigger for medical surveillance June 23, 2018
Offer medical examinations to employees exposed above the PEL for 30 or more days a year June 23, 2018
Offer medical examinations to employees exposed at or above the action level for 30 or more days a year June 23, 2020


Hydraulic Fracturing Operations in the Oil and Gas Industry

Comply with all obligations of the standard, except for engineering controls and action level trigger for medical surveillance June 23, 2018
Offer medical examinations to employees exposed above the PEL for 30 or more days a year June 23, 2018
Comply with requirements for engineering controls to limit exposures to the new PEL.In the interim, employees wear respirators if their exposures exceed the PEL. June 23, 2021
Offer medical examinations to employees exposed at or above the action level for 30 or more days a year June 23, 2020


Each company’s working environment is unique, so no matter how many times you read through a regulation, there are always going to be lingering questions. The new silica rule is no exception. Below we put together some of the most common questions we hear regarding the new silica rule.

So, about this new silica rule.

How often do I need to test for silica?

The short answer is, “it depends.” Let’s dig in.

  • If the initial monitoring indicates that employees are exposed below the action level (25 μg/m3 averaged over an 8-hour day), no further monitoring is required.
  • If the most recent exposure monitoring indicates employees are exposed above the action level but below the PEL (50 μg/m3 averaged over an 8-hour day), monitoring must be repeated within 6 months.
  • If you discovered your employees are exposed above the PEL after your most recent exposure monitoring, you have to repeat monitoring within 3 months.
  • When two non-initial monitoring events are completed consecutively  (at least 7 days apart but within 6 months of each other) and both show results below the action level, you can stop monitoring* employees represented by those results.

*Changes in work practices that could result in new or additional exposure at or above the action level could warrant another round of exposure monitoring.  

When using silica in a hood, do I still need to do air monitoring?

Fume hoods generally protect workers from breathing in hazardous materials. However, you should still ensure the concentration level of silica dust is below the action level. Remember, if you test once and the numbers come back below the action level, you don’t have to test again.

Why can’t I just have my workers wear respirators?

Engineering controls are much more effective than personal protective equipment, including respirators. Respirators also require their fair share of maintenance, and they need to be fitted and refitted on a regular basis. Not to mention, wearing a respirator is uncomfortable.

What about dust collection?

Do I need to use a vacuum with a bag?  

Not necessarily, but it is best practice is to encapsulate any debris or particulate that has crystalline silica dust in it. You can use paper or plastic bags to get the job done.

What do I do once I have a vacuum bag full of silica dust?

You’re responsible for disposing of the material, but how you do it depends on the regulations that apply to your job site. You are still required to follow any applicable local, state, and federal laws for disposing silica waste.

Emptying a vacuum or dust collector can expose a worker to silica dust. How do you recommend minimizing exposure?

This is where PPE comes in. Make sure to wear a respirator, gloves, and safety glasses when you’re emptying vacuums or other dust collecting equipment.  

Let’s talk HEPA.

Can I clean a HEPA filter that was used for cleaning up silica dust?

HEPA filters should never be washed. In fact, if you see a HEPA filter marked as “washable,” it’s not a true HEPA filter and probably doesn’t have a certificate of conformity.  

Can I use a HEPA vacuum to collect wet material?

It’s best to check with the manufacturer. In most cases, HEPA vacuums can collect wet material if it’s properly fitted with a cyclonic filter shield or a main filter designed to prevent moisture from making its way to the HEPA filter.

Additional resources

It never hurts to have a few tabs bookmarked on the silica rule subject. Here are some of our favorite resources.

General information

Compliance guidance

Training material and case studies

Get the guide to-go!

Download Your Silica Compliance Guide

Developing an exposure control plan is an excellent first step towards complying with the new rule — and it won’t bust your budget even with third-party assistance. Contact us today to get started.