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Mercury airborne concentration measurement

Summary An OSHA memorandum clarified how regional offices should apply the mercury value in Table Z-2. It said the 0.1 mg/m³ airborne concentration was determined as a full-shift time-weighted average.
Document
Federal guidance
Agency
Occupational Safety and Health Administration (OSHA)
Document number
1976-06-30
Date issued
June 30, 1976
Status
Active
Status last verified October 10, 2026
Topics
Workplace Safety OSHA 1910 Mercury Air Monitoring
Source
View the official document

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June 30, 1976

MEMORANDUM FOR: OSHA Regional Administrators
FROM: Morton Corn, Assistant Secretary of Labor
SUBJECT: Interpretation of Allowable Airborne Concentrations of Mercury

29 CFR 1910.1000, Table Z-2 contains the ceiling value for mercury. Historically the values in this table relate to the maximum allowable concentrations defined by ANSI as 8 hour time-weighted average.

Therefore, the allowable airborne concentration of mercury shall be interpreted as 0.1 mg/m⁽³⁾ as determined on the basis of the full shift time-weighted average.

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