Silica dust is one of the oldest known occupational hazards, and it is still one of the most dangerous. About 2.3 million people in the U.S. are exposed to silica at work, most of them in construction and manufacturing. The particles that cause harm are too small to see, so a jobsite or shop floor can look clean while workers breathe in dust that slowly scars their lungs.
The issue is getting fresh attention in 2026. A wave of severe silicosis cases among countertop fabricators has pushed regulators, lawmakers and health departments to act, and in February OSHA and NIOSH jointly updated their hazard alerton countertop work. This guide explains where silica exposure happens, what it does to the body, what OSHA requires, and how to build a program that keeps your workers protected and your company compliant.
What Is Crystalline Silica?
Crystalline silica is a natural mineral found in the earth's crust. Quartz is the most common form. It is present in sand, stone, concrete, brick, block and mortar, and it is used to make glass, ceramics, pottery and artificial stone.
In its solid form, silica is harmless. The danger comes when those materials are cut, ground, drilled, blasted or crushed. These tasks release respirable crystalline silica: particles at least 100 times smaller than ordinary beach sand. They are small enough to bypass the body's natural defenses and lodge deep in the lungs.
Common Exposures in Construction
Construction workers face silica exposure on almost every project that involves concrete or masonry. High-risk tasks include:
- Cutting concrete, brick or block with handheld or walk-behind saws
- Grinding and polishing concrete surfaces
- Drilling into concrete walls, floors and ceilings
- Jackhammering and chipping concrete
- Tuckpointing and grinding mortar
- Abrasive blasting with sand
- Demolition and crushing of concrete
Common Exposures in Manufacturing and General Industry
In manufacturing, exposure tends to be ongoing rather than task-based, which can make it easy to overlook. Higher-risk operations include:
- Foundries, where silica sand is used in molds and cores
- Brick, concrete block and precast concrete production
- Glass, ceramics, pottery and tile manufacturing
- Stone countertop fabrication, especially engineered stone
- Hydraulic fracturing (fracking), where industrial sand is moved and handled in large volumes
- Dental laboratories and jewelry making that involve grinding or casting
Health Effects of Silica Exposure
Once respirable silica reaches the lungs, the body can't clear it. The particles trigger inflammation and scarring that keep progressing even after exposure stops. OSHA links silica to four major diseases.
Silicosis
Silicosis is an incurable lung disease. Scar tissue builds up and stiffens the lungs, making it harder and harder to breathe. It comes in three forms:
- Chronic silicosis usually appears after 10 or more years of low to moderate exposure. It is the most common form.
- Accelerated silicosis develops within 5 to 10 years of higher exposure and progresses faster.
- Acute silicosis can appear within weeks to a few years after extremely high exposure. It is often fatal.
Early silicosis may cause no symptoms at all. As it advances, workers develop shortness of breath, a persistent cough, fatigue and chest pain. Severe cases can lead to disability, lung transplant or death. Silicosis also raises the risk of tuberculosis.
Lung Cancer
Crystalline silica is a known human carcinogen. Long-term exposure raises lung cancer risk, and smoking increases that risk further.
COPD and Kidney Disease
Silica exposure is also linked to chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema, and to kidney disease. Some studies also tie it to autoimmune conditions such as rheumatoid arthritis.
The common thread is that these diseases are slow, permanent and entirely preventable. By the time symptoms appear, the damage is done, which is why control has to happen before exposure, not after diagnosis.
OSHA's Silica Standards
OSHA has two respirable crystalline silica standards: one for construction (29 CFR 1926.1153) and one for general industry and maritime (29 CFR 1910.1053). Both took effect under the 2016 silica rule, and both share the same exposure limits.
Exposure Limits
Limit
Value (8-hour time-weighted average)
What it means
Permissible exposure limit (PEL)
50 µg/m³
The maximum average exposure allowed over a work shift
Action level
25 µg/m³
The point that triggers exposure monitoring and, in general industry, medical surveillance
To put this in perspective, 50 micrograms per cubic meter is a tiny amount of dust. You can't judge it by eye, which is why measurement or proven controls are essential.
Key Requirements for Both Standards
Employers covered by either standard must:
- Assess worker exposure to respirable silica
- Use engineering and work practice controls to keep exposure at or below the PEL
- Provide respirators when controls alone aren't enough
- Have a written exposure control plan
- Restrict housekeeping methods that create dust, such as dry sweeping and compressed air, when better options exist
- Offer medical exams, including chest X-rays and lung function tests, to highly exposed workers every three years
- Train workers on silica hazards and how to limit exposure
- Keep records of exposure measurements and medical exams
What's Different in Construction
The construction standard offers a simpler path called Table 1. It lists common tasks, such as cutting with a stationary masonry saw or drilling with a handheld drill, and pairs each with specific controls. Employers who fully and properly implement the Table 1 controls for a task don't need to measure exposure for that task. Construction employers must also designate a competent person to carry out the written exposure control plan, including frequent inspections of jobsites, materials and equipment.
In general industry, there is no Table 1 option. Employers must measure exposures, either through air sampling or objective data, wherever workers may be at or above the action level.
How to Control Silica Exposure
The most effective silica programs follow the hierarchy of controls: remove the hazard where you can, engineer it out where you can't, and rely on respirators only as the last line of defense.
Substitution
Where possible, choose materials with less silica. Foundries can sometimes use non-silica sands. Abrasive blasting can use alternatives such as steel grit, crushed glass or specialty media in place of silica sand. In countertop work, lower-silica or silica-free surfaces greatly reduce risk.
Wet Methods
Water is one of the cheapest and most effective controls. Saws, grinders and drills with integrated water delivery suppress dust at the point of cutting. The key is a steady, sufficient flow of water at the blade or bit, not just a damp surface. Clean up slurry before it dries and becomes airborne again.
Local Exhaust Ventilation
Tools fitted with shrouds and connected to a vacuum dust collector capture dust before it reaches the worker's breathing zone. The vacuum must have a HEPA filter and enough airflow for the tool. In fixed facilities, local exhaust hoods, ventilated booths and enclosed processes do the same job on a larger scale.
Work Practices and Housekeeping
Good habits make engineering controls work better:
- Position workers upwind of dust sources outdoors
- Use HEPA vacuums or wet sweeping instead of dry sweeping or compressed air
- Maintain tools, water systems and dust collectors on a regular schedule
- Limit the number of workers in areas where dust is generated
- Provide wash stations and keep food and drink out of dusty areas
Respiratory Protection
When controls can't keep exposure at or below the PEL, workers need respirators. These must be part of a full respiratory protection program that includes medical clearance, fit testing and training. Table 1 specifies the minimum assigned protection factor for certain construction tasks, such as when a task runs more than four hours per shift.
Engineered Stone: A Growing Silicosis Crisis
The fastest-growing silica problem in the U.S. today is engineered stone, often sold as "quartz" countertops. According to California health officials, engineered stone can contain more than 90 percent crystalline silica. Granite usually contains much less, and marble very little.
Why Fabricators Are at Such High Risk
Cutting, grinding, edging and polishing slabs in small shops can produce very high dust levels, especially when work is done dry. Many affected workers are young. In California, more than 550 workers have been diagnosed with engineered-stone silicosis, and at least 30 have died since 2019. Many were under 50 when diagnosed.
What Employers Should Do
The February 2026 OSHA-NIOSH hazard alert gives countertop shops guidance on keeping exposure below the PEL. Core steps include:
- Use wet methods for every cutting, grinding and polishing step, and never cut dry
- Use local exhaust ventilation and effective general ventilation in the shop
- Measure exposure through air sampling
- Provide respirators, with fit testing, when needed
- Offer medical surveillance, and make sure doctors know workers handle engineered stone
Even if you don't run a fabrication shop, this matters. Installers and remodelers who make field cuts or adjustments face the same hazard, often with fewer controls.
Building a Silica Compliance Program
A strong silica program connects hazard identification, controls, training, medical surveillance and records. Here's a practical path to build one.
- Inventory tasks and materials. List every task that cuts, grinds, drills, blasts, crushes or handles silica-containing materials. Check safety data sheets to confirm silica content.
- Assess exposure. In construction, match each task to Table 1 where possible. For tasks outside Table 1, and for all general industry operations, use air sampling or objective data.
- Write the exposure control plan. Describe each task, the controls in place, housekeeping methods and how you will limit access to high-exposure areas. In construction, name the competent person.
- Install and maintain controls. Buy tools with built-in water or vacuum systems, and add maintenance checks to your preventive maintenance schedule.
- Train every exposed worker. Cover health effects, specific tasks that create exposure, the controls in place and the medical surveillance program. Train in a language workers understand.
- Set up medical surveillance. Partner with an occupational health provider for baseline and three-year exams for workers who meet the trigger.
- Audit and improve. Inspect jobsites and equipment regularly, track corrective actions and review the plan at least annually.
Keep Records Organized
Silica compliance generates a lot of paperwork: sampling results, objective data, training rosters, medical exam records, respirator fit tests and inspection checklists. Exposure and medical records must be kept for the long term, so a centralized digital system makes audits far less painful. EHS software can schedule inspections, track training expiration dates, store safety data sheets and assign corrective actions when a control fails.
Frequently Asked Questions
What is the OSHA permissible exposure limit for silica?
The OSHA permissible exposure limit (PEL) for respirable crystalline silica is 50 micrograms per cubic meter of air (µg/m³), averaged over an 8-hour shift. The same limit applies under both the construction standard and the general industry and maritime standard. OSHA also sets an action level of 25 µg/m³. Exposure at or above the action level triggers additional duties, such as periodic exposure monitoring.
These numbers are very small. A worker can be over the PEL without seeing a visible cloud of dust, because the most harmful particles are too fine to see. That's why employers can't rely on appearances. In general industry, you need air sampling or objective data to know where you stand. In construction, you can either measure or follow Table 1 controls exactly as written for each listed task.
Do I have to do air monitoring if I follow Table 1?
No, not for the tasks covered by Table 1. If a construction employer fully and properly implements the engineering controls, work practices and respiratory protection listed in Table 1 for a specific task, the employer doesn't need to assess exposure for workers doing that task. That's the main advantage of Table 1: it gives a clear, ready-made compliance path for common jobs such as cutting with handheld saws, drilling and grinding.
The catch is the word "fully." If the water flow is too low, the vacuum isn't rated for the tool, or the shroud is damaged, you aren't following Table 1. In that case, or for any task not listed in Table 1, you have to assess exposure through air sampling or objective data and keep it at or below the PEL. Table 1 also doesn't remove other duties: you still need a written exposure control plan, a competent person, training, housekeeping controls and medical surveillance for workers who must wear respirators 30 or more days per year.
Who needs medical surveillance under the silica standards?
The trigger depends on the standard. In construction, employers must offer medical exams to workers who are required to wear a respirator under the silica standard for 30 or more days a year. In general industry and maritime, exams must be offered to workers exposed at or above the action level for 30 or more days a year.
The exam includes a medical and work history, a physical exam focused on the respiratory system, a chest X-ray, a lung function test and a tuberculosis test at the first exam. Exams must be offered at no cost to the worker, at a reasonable time and place, and repeated at least every three years, or more often if the provider recommends it. Workers then receive a written medical opinion. Medical surveillance matters because silicosis is often silent in its early stages, and finding it early can help a worker reduce further exposure before the disease gets worse.
Is a dust mask enough to protect workers from silica?
Usually not on its own. A basic paper dust mask that isn't NIOSH-approved offers little real protection against respirable silica. When respirators are needed, they must be NIOSH-approved and used within a respiratory protection program that includes medical evaluation, fit testing and training. Even a filtering facepiece respirator such as an N95 only works when it fits properly and the wearer is clean-shaven where it seals.
More importantly, respirators are the last line of defense, not the first. OSHA requires employers to use engineering and work practice controls, such as wet cutting and vacuum dust collection, to reduce exposure as far as feasible. Respirators fill the gap only when those controls can't keep exposure at or below the PEL. A program that relies on masks alone will almost always fall short, both for compliance and for worker health.
Why are countertop workers getting silicosis so young?
The main reason is the material. Engineered stone can contain more than 90 percent crystalline silica, far more than most natural stone. When slabs are cut, ground and polished, especially without water or proper ventilation, workers can breathe in very high concentrations of respirable silica in a short time. High exposure leads to accelerated forms of silicosis that can develop in under ten years instead of decades.
The work setting adds to the risk. Many fabrication shops are small, with limited budgets for ventilation, sampling or occupational health services. Some workers are classified as independent contractors, which can leave them outside regular safety programs. Language barriers can also keep training from landing. Employers in this industry should treat engineered stone as a high-hazard material: always cut wet, use local exhaust, sample the air, provide respirators and medical surveillance, and follow the latest OSHA-NIOSH guidance for countertop work.
Protect Workers Before the Damage Is Done
Silica-related disease is permanent, but it is also preventable. Every case of silicosis traces back to dust that could have been controlled with water, ventilation, better materials or proper respiratory protection. For construction and manufacturing employers, the path is clear: identify where silica is present, control it at the source, train your people, monitor their health and keep thorough records.
The engineered stone crisis shows how quickly things can go wrong when controls slip. Use it as a reason to review your own silica program now, before an inspection or a diagnosis forces the issue.
