29 CFR 1910.1018: OSHA Inorganic Arsenic Standard

Regulatory citation: 29 CFR 1910.1018, Inorganic Arsenic

What Is the OSHA Inorganic Arsenic Standard?

Section 1910.1018 covers workplace exposure to inorganic arsenic, meaning all inorganic compounds containing arsenic except arsine gas. It affects copper and other non-ferrous smelters, glass manufacturers, semiconductor makers, pigment and chemical producers, and operations that handle arsenic-bearing dusts and residues.

The standard does not apply to employee exposure in agriculture, pesticide application, treating wood with preservatives, or using wood that has been preserved with arsenic compounds.

Why Arsenic Control Matters

Inorganic arsenic causes lung and skin cancer and can irritate the skin, eyes and nose. Dust settles on clothing and skin, so hygiene and housekeeping controls are as important as air limits.

Core Obligations

1. Keep Exposure Below the Limits (1910.1018(b) and (c))

The permissible exposure limit (PEL) is 10 micrograms per cubic meter of air (µg/m³) averaged over any 8-hour period. The action level is 5 µg/m³. Exposure is measured as if the employee were not wearing a respirator.

2. Monitor Exposure (1910.1018(e))

Samples must be full-shift, covering at least 7 continuous hours. Results above the PEL must be repeated at least quarterly, and results at or above the action level but below the PEL at least every 6 months. Monitoring can stop after two consecutive results, at least 7 days apart, are below the action level. New monitoring is required after changes in production, process, controls or personnel. Employees must be told their results within 15 working days, with a description of corrective action where the PEL was exceeded.

3. Set Up Regulated Areas (1910.1018(f))

Regulated areas are required wherever exposure exceeds the PEL. Everyone entering must be given a respirator. Eating, drinking (other than drinking water), smoking, chewing tobacco or gum, and applying cosmetics are banned inside.

4. Use Controls and a Written Compliance Program (1910.1018(g))

Engineering and work practice controls must reduce exposure to or below the PEL. A written compliance program is required and must be revised and updated at least annually.

5. Provide Respirators and Protective Clothing (1910.1018(h) and (j))

Respirators must be used under a program meeting 29 CFR 1910.134. An employee who has trouble breathing during fit testing or use must be examined by a physician trained in pulmonary medicine. Protective clothing must be provided at no cost in regulated areas and where skin or eye irritation is possible. Clean clothing must be supplied at least weekly, and daily where exposure is over 100 µg/m³ or more washing is needed. Launderers must be told about the hazards in writing, and containers of contaminated clothing must carry the warning label in the standard.

6. Keep Surfaces Clean (1910.1018(k))

Surfaces must be kept as free of arsenic buildup as practicable. Compressed air may not be used for cleaning, and shoveling or brushing is allowed only after vacuuming and other methods have proved ineffective. A written housekeeping and maintenance plan is required.

7. Provide Hygiene Facilities (1910.1018(m))

Employers must provide clean change rooms. Workers in regulated areas, or at risk of skin or eye irritation, must shower at the end of the shift. Lunchrooms must have a temperature-controlled, positive-pressure, filtered air supply, and workers must wash their hands and face before eating.

8. Provide Medical Surveillance (1910.1018(n))

Medical surveillance covers employees exposed above the action level, without regard to respirators, for at least 30 days a year, and employees with 10 or more years of such exposure. The initial exam includes a work, medical and smoking history, a chest X-ray, and a nasal and skin exam. Periodic exams, without the X-ray, are due at least annually. An employee who has not been examined in the 6 months before leaving gets an exam at termination.

9. Train, Post Signs and Keep Records (1910.1018(o) to (q))

Training is required at initial assignment and at least annually for employees exposed above the action level or at risk of skin or eye irritation. Regulated area signs must warn that inorganic arsenic may cause cancer and that respiratory protection is required. Monitoring and medical records must be kept for at least 40 years or the duration of employment plus 20 years, whichever is longer.

Common Compliance Approaches

Separate Clean and Dirty Areas

Route workers from the process area through change rooms and showers before they reach the lunchroom or leave the site.

Check Raw Material Arsenic Content

Ores, concentrates, flue dusts and residues can contain arsenic even when it is not the main product. Review supplier data and sample the material.

Example: Arsenic Controls in Practice

A copper smelter samples its flue dust handlers and finds 18 µg/m³, above the PEL. It sets up a regulated area, issues respirators and daily clean coveralls, and requires showers at the end of every shift. Its written compliance program schedules enclosed conveyors and new local exhaust at the dust bins, and it resamples quarterly. Handlers above the action level for 30 or more days a year get annual medical exams.

Related regulations: OSHA lead in general industry, OSHA respiratory protection, OSHA access to exposure and medical records.

Note: In July 2025 OSHA proposed changes to the respirator provisions of this standard, including replacing the list of situations that require respirators with a cross-reference to 29 CFR 1910.134. The proposal does not change medical surveillance. OSHA reopened the record in July 2026 and held hearings in August 2026. No final rule had been issued as of October 2026, so check for updates. State plan states may set stricter rules.

Frequently Asked Questions

What is the OSHA PEL for inorganic arsenic?

10 µg/m³ averaged over any 8-hour period. The action level is 5 µg/m³.

Does the standard cover arsine gas?

No. Inorganic arsenic is defined as all inorganic arsenic compounds except arsine.

How long must arsenic records be kept?

At least 40 years, or the duration of employment plus 20 years, whichever is longer.