Covers all occupational exposure to respirable crystalline silica (quartz, cristobalite and tridymite in the respirable fraction defined by ISO 7708:1995) in construction, unless exposure will stay under 25 µg/m3 (8-hour TWA) in any foreseeable condition. The action level is also 25 µg/m3. A specialist is an American Board Certified pulmonary disease or occupational medicine physician. Two compliance routes exist. Under paragraph (c), for each employee doing a task listed on Table 1, the employer puts in place, completely and correctly, the controls, work practices and respirator protection the table assigns to that equipment or task; if it does so, it need not assess exposure and is treated as meeting the respirator requirements and 1910.134 selection rules for silica. Table 1 covers eighteen equipment types, pairing each with water delivery, shrouded dust collection, enclosed cabs or similar controls and, for some, a minimum assigned protection factor (APF) set by shift duration (up to or over four hours) and location. For example, stationary masonry saws with an integrated water feed need no respirator; handheld power saws with water feed need APF 10 indoors or in enclosed areas and outdoors beyond four hours; handheld tuckpointing grinders need a shroud and a dust collector giving 25 cfm or more per inch of wheel diameter with 99% filtration, plus APF 10 up to four hours and APF 25 beyond; heavy equipment used to fracture or demolish silica materials is run from an enclosed cab, with water or suppressants when workers outside the cab take part. When using Table 1, indoor tasks get exhaust as needed, wet methods use enough water to minimise visible dust, and enclosed cabs or booths are kept clean, sealed, under positive pressure with fresh air filtered to 95% efficiency in the 0.3 to 10.0 µm range (for example MERV-16), and heated and cooled. Where an employee does several Table 1 tasks totalling more than four hours in a shift, the over-four-hours respirator level applies to each. Under paragraph (d), for unlisted tasks or incomplete Table 1 implementation, the PEL is 50 µg/m3 (8-hour TWA). Employees who may reach the action level have exposure assessed by the performance option or scheduled monitoring: initial breathing zone sampling per shift, job classification and area (representative sampling of the highest exposed allowed); stop if below the action level; repeat within six months between the action level and PEL, within three months above the PEL; stop after two consecutive results at least seven days apart below the action level; reassess after changes. Samples go to a laboratory meeting mandatory Appendix A (OSHA ID-142, NMAM 7500, 7602 or 7603, or MSHA P-2 or P-7; ISO/IEC 17025 accreditation; NIST or NIST-traceable calibration; internal quality control; calibration checks on each day samples are analysed, calibration curves built from five or more standard levels; detection limit not above one quarter (25 percent) of the PEL). Results go to employees within five working days, with corrective action if above the PEL. Engineering and work practice controls come first, with respirators under a 1910.134 program supplementing them; abrasive blasting also follows 1926.57. Housekeeping: no dry sweeping or brushing unless wet sweeping, HEPA vacuuming or similar methods are infeasible; no compressed air on clothing or surfaces unless used with capture ventilation or no alternative is feasible. A written exposure control plan describes the tasks, the controls and respirators for each, housekeeping measures and access restriction procedures (including exposure from other employers or sole proprietors); it is reviewed at least annually and available on request, and a designated competent person makes frequent and regular inspections to implement it. Medical surveillance is offered free to employees required to wear respirators on 30 days or more per year: a baseline exam within 30 days of assignment unless one was done within three years (history, respiratory exam, chest X-ray classified by a NIOSH-certified B Reader, spirometry by a technician currently certified through a NIOSH-approved spirometry course, latent TB testing), repeated at least every three years (without TB testing) or more often if recommended. The employee receives a written report and the employer a limited written opinion within 30 days; a specialist exam follows within 30 days when the opinion calls for one, such as a 1/0 or higher X-ray. The HCS program covers cancer, lung, immune system and kidney effects; employees must know the hazards, tasks, controls, the standard, the competent person's identity and the medical program. Air monitoring, objective data and medical records follow 1910.1020. Obligations began 23 June 2017 and the laboratory requirements 23 June 2018, so all are in force.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.