1910.1000(b)(1): Table Z-2 8-Hour Exposure Limits
An employee's exposure to any substance listed in Table Z-2, in any 8-hour work shift of a 40-hour work week, must not exceed the 8-hour time weighted average limit given for that substance in Table Z-2.
Key takeaways
- 1910.1000(b)(1) is part of OSHA's general industry standards (29 CFR Part 1910).
- OSHA cited it 3 times in the last 3 years, in 3 inspections, with $21,389 in current penalties.
- 1 death is linked to inspections that cited this rule.
- Related part: 1910.1000(b) Table Z-2 (12 citations).
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In this article
What this rule covers
29 CFR 1910.1000(b)(1) ("8-hour time weighted averages") is one requirement inside 1910.1000 Air contaminants, an OSHA general industry standard (Part 1910). The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(1) 8-hour time weighted averages. An employee's exposure to any substance listed in Table Z-2, in any 8-hour work shift of a 40-hour work week, shall not exceed the 8-hour time weighted average limit given for that substance in Table Z-2. 3 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.1000.
Export the list: 3 inspections cited 1910.1000(b)(1) in the last 3 years, with employer, location, penalty and date.
Purple Belt, $59/moInjuries linked to this rule
1 death is linked to inspections where OSHA cited 1910.1000(b)(1).
At 10:45 a.m. on August 1, 2024, an employee was found unconscious after pressure washing the inside of a walk-in cooler with a gas operated pressure washer. The employee was killed due to suspected carbon monoxide poisoning.
Where and how often it was cited
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OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.1000(b)(1).
Related parts of this rule
- 1910.1000(b) Table Z-2 12 citations
- 1910.1000(b)(2) Acceptable ceiling concentrations 9 citations
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Frequently asked questions
What does the Table Z-2 8-hour limit apply to?
An employee's exposure in any 8-hour work shift of a 40-hour work week.
Where are the limits listed?
In Table Z-2 for each listed substance.
Can exposure go above the TWA limit?
Exposure shall not exceed the 8-hour time weighted average limit given for that substance.
About this page
Sources
- 29 CFR 1910.1000 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-11-06
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.