16.1 PEL, Action Level, and Exposure Assessment

PEL 50, action level 30, and the assessment that cannot hide behind a respirator

Quick Answer: 29 CFR 1926.62 is the OSHA construction lead standard. The permissible exposure limit (PEL) is 50 µg/m³ as an 8-hour time-weighted average (TWA). If the workday is not 8 hours, allowable exposure (µg/m³) = 400 ÷ hours worked that day. The action level is 30 µg/m³ as an 8-hour TWA. For exposure assessment, employee exposure is the concentration that would occur if the employee were not using a respirator. Until you document otherwise, listed trigger tasks are treated as over the PEL in three bands: Group 1 >PEL but ≤10× PEL (500 µg/m³); Group 2 >500 µg/m³; Group 3 >2,500 µg/m³. Below the action level, you need not repeat monitoring except after changes. From the action level through the PEL, monitor at least every 6 months until two consecutive results at least 7 days apart are below the action level. Above the PEL, monitor quarterly until two consecutive results ≥7 days apart are at or below the PEL. Engineering and work-practice controls come first; respirators supplement feasible controls.

This is the worker-protection chapter. EPA Subpart L (Chapters 1–15, 18) tells you how to abate target housing and child-occupied facilities. 1926.62 tells you how to keep employees from inhaling and absorbing the dust that abatement creates. An EPA supervisor card does not waive OSHA. Blood-lead medical removal is Section 16.3. The two hats — OSHA competent person versus EPA certified supervisor — are Section 16.4. This section is the air numbers, the trigger-task table, and the monitoring calendar.

1926.62(a) covers construction work where an employee may be occupationally exposed to lead, including removal or encapsulation of materials containing lead, demolition or salvage where lead is present, renovation of structures that contain lead, emergency cleanup, and on-site transportation, disposal, storage, or containment of lead materials. Residential LBP abatement is construction lead work. Do not tell the exam that OSHA applies only to bridges and tanks.

Memorize the air numbers with their units

µg/m³ is air, not blood. A PEL of 50 is 50 µg/m³. A construction medical-removal BLL of 50 is 50 µg/dL. EPA's occupant EBL in 745.223 is 20 µg/dL. Chapter 4 already beat this drum. This chapter will keep beating it because exam writers mix the three on purpose.

Worked example — 10-hour shift. Crew is on a 10-hour day of interior wet scrape. Allowable TWA for that day is 400 ÷ 10 = 40 µg/m³, not 50. An 8-hour TWA of 45 that looked “under the PEL” on an 8-hour mental calendar is over the allowable exposure on a 10-hour day. The action level remains 30 µg/m³ as an 8-hour TWA; do not invent a scaled action level.

Exposure for monitoring is the unprotected concentration

1926.62(d)(1)(ii): for purposes of paragraph (d), employee exposure is the exposure that would occur if the employee were not using a respirator. Personal samples must represent a full shift, with at least one sample for each job classification in each work area, either for each shift or for the shift with the highest exposure.

That sentence is the trap after “everyone is in a half-mask.” A heat-gun operator whose cassette reads 80 µg/m³ outside the respirator is an over-PEL employee for assessment, hygiene, clothing, and the monitoring calendar, even if the assigned protection factor would bring the in-mask concentration under 50. Respirators may be used to limit exposure under (c) and (f) once engineering controls and a respirator program are in place. They do not rewrite the (d) number.

The employer must initially determine whether any employee may be exposed at or above the action level. Negative initial determinations are written: date, location, names of employees monitored, and the information in (d)(3)(i). Objective data cannot be used to skip assessment of the listed trigger tasks in (d)(2). Prior monitoring from the past 12 months may be used only if the work closely resembles the current processes, materials, controls, practices, and conditions and the method meets the accuracy rule — ±25 percent at a 95 percent confidence level at concentrations ≥30 µg/m³.

Notify each affected employee of monitoring results as soon as possible but no later than 5 working days after the employer receives the results, in writing or by posting in an accessible location. If the representative exposure without regard to respirators is at or above the PEL, the notice must say so and describe the corrective action taken or to be taken.

Trigger tasks — treat them as over the PEL until the cassette says otherwise

Until the employer performs the (d) assessment and documents that the employee is not in the assumed band, listed tasks where lead is present are treated as over-exposures. Interim protection in (d)(2)(v) is not optional theater: respiratory protection, protective clothing, change areas, hand-washing facilities, biological monitoring (blood lead and zinc protoporphyrin), and training (hazard communication, respirator use, and 1926.21 safety training).

(d)(2)(ii) is the catch-all: a task not on those lists, if the employer has any reason to believe the employee may be exposed above the PEL, is treated as above the PEL until assessment documents otherwise.

Worked example — same window, three tools. A 1925 sash is LBP. Heat gun below 1100°F (EPA-restricted-practice chapter still applies) is Group 1: treat as >50 and ≤500 µg/m³ until the cassette says otherwise — half-mask HEPA territory on the APF table (Section 16.2), plus clothing, change area, handwashing, and a BLL/ZPP. Switch to a needle gun without a shroud and HEPA collection and you have moved to Group 2: treat as >500 µg/m³. A half-mask APF of 10 is no longer enough on the assumed number. Switch to torch burning the same sash and you have jumped to Group 3 — and you have also walked into EPA's open-flame burning/torching prohibition in 745.227(e)(6). OSHA's assumed band does not legalize an EPA-restricted practice.

Do not “wait for lab results” before putting the crew in interim protection. The whole point of (d)(2) is that the first day of a listed task is already an over-PEL day until you document it is not.

Monitoring calendar after you have real numbers

(d)(7) additional assessments are not a courtesy: a change of equipment, process, control, or personnel, or a new task that may expose additional employees at or above the AL or push already-exposed employees above the PEL, requires more monitoring. Swapping a shrouded sander for a bare grinder is a (d)(7) event, not a “same room, same paperwork” event.

Worked example — two cassettes, seven days. Day 1 of wet scrape: 42 µg/m³ (AL to PEL) — 6-month schedule starts. Day 10: 22 µg/m³. You cannot drop monitoring on one below-AL result. You need a second below-AL result at least 7 days after the first. Day 12 at 18 µg/m³ is only two days later; it does not count as the pair.

Engineering first, then respirators; HEPA, not compressed air

1926.62(e)(1) is the hierarchy in one paragraph. Implement engineering and work-practice controls, including administrative controls, to reduce and maintain exposure to or below the PEL to the extent such controls are feasible. If feasible controls are not enough, still use them to the lowest feasible level and supplement with respiratory protection that meets (f). A half-mask is not a substitute for a shroud, wet methods, local exhaust, or a HEPA vacuum.

Housekeeping (h): keep surfaces as free as practicable of lead. Clean by vacuuming or other methods that minimize airborne lead. Where a vacuum is used, it shall have a HEPA filter. Shoveling, dry or wet sweeping, and brushing only after vacuuming or an equally effective method has been tried and found not effective. Compressed air shall not be used to remove lead from any surface unless it is used with a ventilation system designed to capture the dust. Chapter 14 already taught HEPA / wet / HEPA as EPA/HUD cleanup. This is the OSHA sentence that makes a shop-vac blower a citation, not a shortcut.

Written compliance program (e)(2): establish and implement it prior to commencement of the job. It describes each lead-emitting activity, the means of compliance, engineering plans where engineering controls are required, air-monitoring data, a schedule, work-practice and hygiene items, multi-contractor arrangements, and frequent and regular inspections of job sites, materials, and equipment by a competent person. Update at least annually. The competent person is Section 16.4; the point here is that exposure assessment is not a one-page “we use respirators” letter.

Supervisor decision test. (1) Is this construction lead work under 1926.62(a)? Residential abatement is. (2) What is today's allowable TWA — 50, or 400 ÷ hours? (3) For assessment, did you treat the cassette as unprotected? (4) Is the task a listed trigger, and which assumed band? (5) Are interim protections on before the lab calls? (6) After you have numbers, are you on the 6-month or quarterly calendar, and do you have two consecutive results ≥7 days apart before you drop a tier? (7) Did engineering and work practices go in before you called the respirator the control?

Official sources: 29 CFR 1926.62(b)–(e), (h) (definitions, PEL, exposure assessment, trigger tasks, methods of compliance, housekeeping); eCFR 29 CFR 1926.62.