Workers in construction are at risk for exposure to crystalline silica, a common mineral found in construction materials like concrete, brick, mortar, sand, and stone. If you have ever seen a sidewalk being jackhammered, and concrete dust blowing in the air, you have probably seen respirable crystalline silica. When workers cut, crush, saw, grind, or perforate these types of materials, very small airborne particles are created. These “respirable” particles can travel deep into workers’ lungs. Each year, about two million construction workers are exposed to crystalline silica at over 600,000 job sites.
Diseases from Respirable Silica Dust
If you see a worker in a cloud of dust without a mask, they might be at risk of developing silicosis, an incurable and sometimes deadly lung disease. Silica dust can also cause lung cancer, obstructive chronic pulmonary disease, and kidney disease. Generally, these occur after years of prolonged exposure to respirable crystalline silica.
The OSHA Standard
The OSHA Standard that addresses Crystaline Silica in Construction is 29 CFR 1926.1153. This standard requires employers to limit worker exposure to crystalline silica and/or provide engineering and work practice control methods for specific equipment and tasks. If employers do NOT use Table 1 of the standard for guidance, they are REQUIRED to determine the amount of silica that workers are being exposed to and find alternate exposure control methods.
The action level for silica is 25 micrograms per cubic meter of air (µg/m³). The permissible exposure limit (PEL) for silica is 50 µg/m³ over an 8-hour day, and workers must be protected at or above the PEL. Employers may use dust controls and safer work methods, or provide respirators, when the amount of dust cannot be kept under the PEL.
Table 1
Table 1 of the construction standard matches eighteen (i-xviii) common construction tasks that involve dust with effective control methods. The equipment/task is listed at the left, with a picture of the task. In the middle is a description of the engineering and work practice control methods recommended by OSHA, and on the right the required respiratory protection and minimum protection factor is listed for more and less than 4-hour exposures.
Example – Table 1 (xviii)
The following is an example from Table 1 of the OSHA Respirable Crystalline Silica Standard – 29 CFR 1926.1153.
Equipment/Task: If heavy equipment and/or utility vehicles are being used for grading and excavating (but NOT demolishing, abrading, or fracturing silica-based materials) then:
The recommended engineering and work practice control methods would be:
- Apply water and/or dust suppressants as necessary to minimize dust emissions OR
- When the equipment operator is the only employee engaged in the task, operate equipment from within an enclosed cab.
Lastly, the timeframe of exposure recommendations for this equipment and task are:
Required respiratory protection and minimum assigned protection factor (APF): NONE. For whether more or less than 4 hours, it is not necessary to wear respiratory protection or have protection that meets any APF factor.
Additional Requirements
Independent of control methods, all employers in the construction industry are required to:
- Establish and implement a written exposure control plan;
- Designate a competent person to implement the written control plan;
- Restrict housekeeping practices that expose workers to silica;
- Offer medical exams including chest X-rays and lung function tests every three years (for workers required to wear respirators 30 days or more a year);
- Train workers about silica and exposure prevention; and
- Keep records of workers’ silica exposure and medical exams.
DON’T TAKE A CHANCE…GIVE TABLE 1 A GLANCE!
Download flyer: SMOTW_1219_Silica_Dust_Standard Download Spanish flyer: SMOTW_1219_Silica_Dust_Standard_esp
