Guidance for the Respirable Crystalline Silica in Construction Standard, 29 CFR 1926.1153

The Respirable Crystalline Silica in Construction standard establishes a new 8-hour time weighted average (TWA) permissible exposure limit (PEL) of 50 µg/m3, and an action level (AL) of 25 µg/m3. This new standard applies to all occupational exposures to respirable crystalline silica in construction work, except where employee exposure will remain below the AL of 25 µg/m3 as an 8-hour TWA under any foreseeable conditions. OSHA is enforcing all appropriate provisions of the Silica in Construction standard.

​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, such as use of compressed air without a ventilation system to capture the dust and dry sweeping, where effective, safe alternatives are available;
• Offer medical exams, including chest X-rays and lung function test, 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 the health effects of silica exposure, workplace tasks that can expose them to silica, and ways to limit exposure; and
• Keep records of workers’ silica exposure and medical exams.

​Note that the standard contains a unique, option for employers whose employees are engaged in the construction tasks listed in Table 1 at  29 CFR 1926.1153(c)(1). Table 1 contains 18 common construction tasks. Each task is matched to specific engineering and work practices. Employers who fully and properly implement the engineering controls, work practices, and respiratory protection listed in Table 1, are not required to conduct exposure assessments or otherwise comply with a PEL for employees engaged in those tasks. Table 1 contains the following eighteen (18) tasks:

1. Stationary masonry saws
2. Handheld power saws (any blade diameter)
3. Handheld power saws for cutting fiber-cement board (with blade diameter of 8 inches or less)
4. Walk-behind saws
5. Drivable saws
6. Rig-mounted core saws or drills
7. Handheld and stand-mounted drills (including impact and rotary hammer drills)
8. Dowel drilling rigs for concrete
9. Vehicle-mounted drilling rigs for rock and concrete
10. Jackhammers and handheld powered chipping tools
11. Handheld grinders for mortar removal (i.e., tuckpointing)
12. Handheld grinders for uses other than mortar removal
13. Walk-behind milling machines and floor grinders
14. Small drivable milling machines (less than half-lane)
15. Large drivable milling machines (half-lane and larger)
16. Crushing machines
17. Heavy equipment and utility vehicles used to abrade or fracture silica-containing materials (e.g., hoe-ramming, rock ripping) or used during demolition activities involving silica-containing materials
18. Heavy equipment and utility vehicles for tasks such as grading and excavating but not including: Demolishing, abrading, or fracturing silica-containing materials

If employer has not fully and properly implemented controls listed on Table 1 and/or have employees working on tasks not listed on Table 1, then it must comply with: Alternative exposure control methods at 29 CFR 1926.1153(d) which includes exposure assessments and shall ensure that no employee is exposed to an airborne concentration of respirable crystalline silica in excess the PEL of 50 μg/m3, calculated as an 8-hour TWA.

Reference:
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Part Number: 1926. Part Title: Safety and Health Regulations for Construction. Subpart: Z. Subpart Title: Toxic and Hazardous Substances. Standard Number: 1926.1153. Title: Respiratory Crystalline Silica.  Appendix: A, B. GPO Source: e-CFR. https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=1270