1910.1052(d)(1): Characterizing Methylene Chloride Exposure
Where methylene chloride (MC) is present, employers must find each employee's exposure with personal breathing zone samples of each employee or representative samples. Representative samples must cover each job classification, work area and shift, using the employee expected to have the highest exposure, with one shift's samples usable for others if conditions are documented as similar. Results must meet set accuracy levels at 95 percent confidence.
Key takeaways
- 1910.1052(d)(1) is part of OSHA's general industry standards (29 CFR Part 1910).
- OSHA cited it 21 times in the last 3 years, in 21 inspections, with $53,718 in current penalties.
- Most citations: MI (4), OR (4), TN (2).
- Related part: 1910.1052(d) Exposure monitoring (70 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.1052(d)(1) ("Characterization of employee exposure") is one requirement inside 1910.1052 Methylene chloride, an OSHA general industry standard (Part 1910). It includes 10 sub-paragraphs. 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) Characterization of employee exposure. 21 citations
(i) Where MC is present in the workplace, the employer shall determine each employee's exposure by either: Open (d)(1)(i) 21 citations
(A) Taking a personal breathing zone air sample of each employee's exposure; or 1 citations
(B) Taking personal breathing zone air samples that are representative of each employee's exposure. 1 citations
(ii) Representative samples. The employer may consider personal breathing zone air samples to be representative of employee exposures when they are taken as follows: Open (d)(1)(ii)
(A) 8-hour TWA PEL. The employer has taken one or more personal breathing zone air samples for at least one employee in each job classification in a work area during every work shift, and the employee sampled is expected to have the highest MC exposure.
(B) Short-term exposure limits. The employer has taken one or more personal breathing zone air samples which indicate the highest likely 15-minute exposures during such operations for at least one employee in each job classification in the work area during every work shift, and the employee sampled is expected to have the highest MC exposure.
(C) Exception. Personal breathing zone air samples taken during one work shift may be used to represent employee exposures on other work shifts where the employer can document that the tasks performed and conditions in the workplace are similar across shifts.
(iii) Accuracy of monitoring. The employer shall ensure that the methods used to perform exposure monitoring produce results that are accurate to a confidence level of 95 percent, and are:
(A) Within plus or minus 25 percent for airborne concentrations of MC above the 8-hour TWA PEL or the STEL; or
(B) Within plus or minus 35 percent for airborne concentrations of MC at or above the action level but at or below the 8-hour TWA PEL.
Source: eCFR, text current as of 2026-10-15. Read all of 1910.1052.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2024 | 7 |
| 2025 | 9 |
| 2026 | 5 |
Top states: MI (4), OR (4), TN (2), ID (2), CO (2)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| SUNFLOWER MANUFACTURING, LLC | HUDSON, CO | $11,916 |
| THE SAYLES COMPANY LLC | COLUMBUS, OH | $9,268 |
| FORBO FLOORING INC | HAZLETON, PA | $8,000 |
| NOW HEALTH GROUP, INC | BLOOMINGDALE, IL | $6,857 |
| DANA CONTAINER, INC. | DETROIT, MI | $4,500 |
Free toolbox talk
A 5-minute crew talk on 1910.1052(d)(1), plus alerts when this rule changes. Free.
OSHA interpretation letters
Related parts of this rule
- 1910.1052(d) Exposure monitoring 70 citations
- 1910.1052(d)(2) Initial determination 46 citations
- 1910.1052(d)(1)(i) 21 citations
- 1910.1052(d)(1)(ii) Representative samples
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 must MC exposure be determined?
By personal breathing zone air samples of each employee's exposure, or samples representative of each employee's exposure.
Who is sampled in representative sampling?
At least one employee in each job classification in a work area during every work shift, expected to have the highest MC exposure.
How accurate must monitoring be?
Accurate to a 95 percent confidence level, within plus or minus 25 percent above the TWA PEL or STEL, and within plus or minus 35 percent at or above the action level but at or below the TWA PEL.
About this page
Sources
- 29 CFR 1910.1052 (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 2026-10-20
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.