1926.55(a)(2): 8-Hour Exposure Limits in Construction
Employers must keep each construction worker's exposure to substances in Table 1 or 2 with a limit not marked (C) from exceeding the listed limit, measured as an 8-hour time-weighted average in any work shift. Exposure is determined from breathing-zone air samples.
Key takeaways
- 1926.55(a)(2) is part of OSHA's construction standards (29 CFR Part 1926, Subpart D).
- OSHA cited it 34 times in the last 3 years, in 34 inspections, with $475,524 in current penalties.
- 1 death is linked to inspections that cited this rule.
- Most citations: WI (4), CT (3), ND (3).
- Related part: 1926.55(a) (47 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1926.55(a)(2) ("Other substances—8-hour Time Weighted Averages") is one requirement inside 1926.55 Gases, vapors, fumes, dusts, and mists, an OSHA construction standard (Part 1926, Subpart D). 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
(2) Other substances—8-hour Time Weighted Averages. An employee's exposure, as determined from breathing-zone air samples, to any substance in Table 1 or 2 of this section with a permissible exposure limit not preceded by (C) must not exceed the limit specified for that substance measured as an 8-hour time-weighted average in any work shift. 34 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1926.55.
Injuries linked to this rule
1 death is linked to inspections where OSHA cited 1926.55(a)(2).
At 5:28 p.m. on November 3, 2023, Employee #1 was employed by a specialty door contractor. Employee #1 had installed the first of four garage doors and was inthe process of completing the installation of the second garage door at a residential home. Employee #1…
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 3 |
| 2024 | 13 |
| 2025 | 9 |
| 2026 | 9 |
Top states: WI (4), CT (3), ND (3), TN (3), OH (2)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| NORTHWEST CONTRACTING, INC. | BISMARCK, ND | $148,963 |
| RIEGER, BORGEN, BENSON ELECTRIC, INC. | BISMARCK, ND | $92,688 |
| NORTH TEXAS CONTRACTING, INC. | PLANO, TX | $16,550 |
| PKG CONTRACTING, INC. | SELBY, SD | $14,895 |
| WHITECO LLC | TOMAH, WI | $14,895 |
Free toolbox talk
A 5-minute crew talk on 1926.55(a)(2), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1926.55(a)(2).
Related parts of this rule
- 1926.55(a) 47 citations
Get your crew competent
Trainers on Black Belt Safety: Marc Harvey, Dana Reyes
Trainers and suppliers: feature your business on this rule for $25/month.
Frequently asked questions
How is exposure measured under this rule?
From breathing-zone air samples, measured as an 8-hour time-weighted average.
Which substances does this cover?
Substances in Table 1 or 2 of 1926.55 whose limit is not preceded by (C).
Does the limit apply to every shift?
Yes. Exposure must not exceed the limit in any work shift.
About this page
Sources
- 29 CFR 1926.55 (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 2026-10-19
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.