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General Industry (29 CFR 1910)

Methylene Chloride

Verified vs OSHA sources · 2026-10-05

29 CFR 1910.1052

29 CFR 1910.1052 protects general-industry workers from methylene chloride (dichloromethane, or MC), a solvent that is a carcinogen and metabolizes to carbon monoxide, stressing the heart. It caps exposure at 25 ppm as an 8-hour TWA with a 125 ppm 15-minute STEL and a 12.5 ppm action level, requiring monitoring, controls, and medical surveillance.

29 CFR 1910.1052 at a glance

PEL
25 ppm as an 8-hour TWA (29 CFR 1910.1052(c)(1))
STEL
125 ppm over any 15-minute period (1910.1052(c)(2))
Action level
12.5 ppm (8-hr TWA): triggers monitoring and medical surveillance
Health effect
Carcinogen that metabolizes to carbon monoxide, stressing the heart
Max penalty (2026)
$16,550 per serious violation; $165,514 per willful
The #1 confusion
Methylene chloride becomes carbon monoxide in the body: a cardiac hazard, not just a solvent

What 29 CFR 1910.1052 requires (plain English)

29 CFR 1910.1052 protects general-industry workers from methylene chloride (dichloromethane, or MC): a chlorinated solvent used in paint stripping, degreasing, adhesives, and pharmaceutical manufacturing. It is a carcinogen, and uniquely among solvents it metabolizes in the body to carbon monoxide, reducing the blood's oxygen-carrying capacity and stressing the heart.

The standard sets a permissible exposure limit of 25 ppm as an 8-hour time-weighted average, a short-term exposure limit of 125 ppm over any 15 minutes, and an action level of 12.5 ppm. Above the action level, employers must conduct exposure monitoring and provide medical surveillance; where exposures exceed the limits, engineering and work-practice controls (local exhaust ventilation, enclosure) are the primary means of compliance, with regulated areas, respirators, and protective equipment as needed.

1910.1052 is one of the Subpart Z substance-specific health standards, alongside benzene (1910.1028) and formaldehyde (1910.1048). Because MC's acute hazard (carbon monoxide poisoning in confined, unventilated spaces such as bathtub refinishing) has caused sudden worker deaths, the standard's ventilation and monitoring requirements address both chronic cancer risk and immediate lethality.

The regulatory text

“The employer shall ensure that no employee is exposed to an airborne concentration of MC in excess of twenty-five parts of MC per million parts of air (25 ppm) as an 8-hour TWA.”
29 CFR 1910.1052(c)(1)

Key facts about 29 CFR 1910.1052

  • The methylene chloride PEL is 25 ppm as an 8-hour TWA (1910.1052(c)(1)).
  • A short-term exposure limit caps exposure at 125 ppm over any 15 minutes (1910.1052(c)(2)).
  • The action level is 12.5 ppm (8-hr TWA) and triggers monitoring and medical surveillance.
  • Methylene chloride is a carcinogen and metabolizes to carbon monoxide, stressing the heart.
  • It has caused sudden deaths in bathtub refinishing and other confined, unventilated work.
  • Engineering controls (ventilation, enclosure) are the primary means of meeting the limits.
  • Common uses: paint stripping, degreasing, adhesives, and pharmaceutical manufacturing.

Scope: who 29 CFR 1910.1052 applies to

Regulatory framework
General Industry (29 CFR 1910)
Citation reference
29 CFR 1910.1052
Enforcement status
In force and enforced
Jurisdiction
Federal OSHA (29 State-Plan jurisdictions may be stricter)

State-Plan states (e.g. California, Washington, Michigan) operate OSHA-approved programs that must be at least as effective as federal OSHA and frequently impose higher penalties or additional requirements. Confirm the rule as adopted in your state.

Key requirements of 29 CFR 1910.1052

#Employer obligation
1Limit exposure to 25 ppm PEL (8-hr TWA)
2STEL of 125 ppm (15-minute)
3Monitor exposure above action level (12.5 ppm)
4Provide medical surveillance for cardiac risk
5Establish regulated areas above PEL
6Use engineering controls as primary method

Summarized from the text of 29 CFR 1910.1052. Always read the full regulation for the binding language.

Common Methylene Chloride violations

Deficiencies OSHA cites under 29 CFR 1910.1052 include the ones below, in no particular order. Distinct deficiencies can be cited as separate items, and each serious item carries up to $16,550 (2026). Broader per-instance stacking exists but is a discretionary, case-by-case OSHA enforcement policy, not an automatic multiplier.

  • No exposure monitoring for operations using methylene chloride above the action level (1910.1052(d)).
  • Exposures above the PEL or STEL without adequate engineering controls (1910.1052(f)).
  • No medical surveillance for workers at or above the action level (1910.1052(j)).
  • No regulated area where exposure exceeds the PEL or STEL (1910.1052(e)).
  • Reliance on respirators instead of ventilation for stripping and refinishing (1910.1052(f)).

Methylene chloride becomes carbon monoxide in the body: it is more than a solvent

Workers often treat methylene chloride as an ordinary solvent and focus only on ventilation for the vapor smell. In fact MC has two distinct hazards: it is a carcinogen, and it metabolizes in the body to carbon monoxide, which binds hemoglobin and starves the heart and brain of oxygen. That is why it has killed workers doing paint stripping and bathtub refinishing in small, poorly ventilated spaces: they were effectively being poisoned by carbon monoxide their own bodies generated from the solvent. Controlling exposure to the 25 ppm PEL and 125 ppm STEL, especially with ventilation in confined areas, addresses both the cancer risk and the acute cardiac hazard.

What OSHA inspectors look for

A compliance officer checks exposure monitoring for methylene-chloride operations (paint stripping, degreasing, adhesives), verifies engineering controls before respirators, confirms medical surveillance above the action level, and checks regulated-area controls where the STEL or PEL is exceeded. Paint-stripping with no ventilation or monitoring is the classic finding.

Example: how a violation is cited

A worker strips paint in an unventilated bathtub-refinishing job and is overcome: methylene chloride metabolizes to carbon monoxide and has caused sudden deaths in refinishing. OSHA cites 1910.1052 for the overexposure and missing controls, with penalties from $16,550.

Illustrative example, not a specific OSHA case.

Methylene Chloride compliance checklist

Use this to evaluate your compliance with 29 CFR 1910.1052. Each item is a key requirement OSHA may verify during an inspection.

  • Identify methylene-chloride operations (stripping, degreasing, adhesives) and monitor exposures.
  • Reduce exposure to the 25 ppm PEL and 125 ppm STEL primarily with local exhaust ventilation and enclosure.
  • Provide medical surveillance for workers at or above the 12.5 ppm action level.
  • Establish regulated areas where exposure exceeds the PEL or STEL.
  • Provide respirators and protective equipment where controls are insufficient, and never rely on them alone in confined spaces.
  • Train workers on the carbon-monoxide metabolism hazard, especially for confined-space refinishing.

2026 penalties for 29 CFR 1910.1052

Maximums set by 29 CFR 1903.15(d). 2026 amounts unchanged from 2025 (no CPI adjustment; OMB M-26-11). Not an increase. The 2025 OSHA penalty levels remain in effect for 2026; OSHA made no inflation adjustment for 2026. 29 CFR 1903.15 identifies January 15, 2025 as the effective reference for these amounts, while OSHA's public penalties page currently references penalties assessed after Jan. 15, 2026.

Violation typeMinimumMaximumWhen it applies
Serious$1,085$16,550Substantial probability of death or serious physical harm.
Other-Than-Serious$0$16,550Relates to safety/health but unlikely to cause death or serious harm.
Willful$11,823$165,514Intentional, knowing, or voluntary disregard of the requirement.
Repeated$4,256$165,514A substantially similar violation cited within the last 5 years.
Failure to AbateNone$16,550/dayup to $16,550 per day; total capped at 30x the daily amount (FOM Ch.6)

Methylene-chloride citations follow refinishing, stripping, and degreasing exposures. Serious violations reach $16,550 and willful or repeat violations $165,514; overexposure without ventilation or monitoring is the usual finding.

Maximums and the willful minimum are set by 29 CFR 1903.15(d); the serious and repeated minimums are OSHA policy floors from its annual penalty adjustment memo. OSHA applies gravity-based and size, good-faith and history reductions (FOM CPL 02-00-164 Ch.6). Estimates only, not legal advice.

The business case for Methylene Chloride compliance

Methylene chloride is a carcinogen and, uniquely, metabolizes in the body to carbon monoxide, cutting oxygen delivery and stressing the heart: it has killed workers doing bathtub refinishing in small unventilated spaces. Keeping exposure under the 25 ppm PEL and 125 ppm STEL with ventilation prevents both the cancer risk and the acute deaths.

Free compliance tools for 29 CFR 1910.1052

SDS Gap AnalyzerRespiratory Protection Program BuilderPPE Selector

Methylene Chloride penalties by state

Penalties and enforcement vary by state. State-Plan states may impose higher penalties and additional requirements beyond federal 29 CFR 1910.1052.

AlabamaArkansasColoradoConnecticutDelawareDistrict of Columbia
View all 50 states + DC →

Frequently asked questions about 29 CFR 1910.1052

What is the OSHA methylene chloride PEL?

Under 1910.1052(c), the permissible exposure limit for methylene chloride is 25 ppm as an 8-hour time-weighted average, with a short-term exposure limit of 125 ppm over any 15-minute period. An action level of 12.5 ppm (8-hour TWA) triggers exposure monitoring and medical-surveillance obligations.

Why is methylene chloride especially dangerous in confined spaces?

Because it metabolizes in the body to carbon monoxide. In a small, poorly ventilated space such as a bathtub being refinished, methylene chloride vapor is inhaled at high concentrations and the body converts it to carbon monoxide, which starves the heart and brain of oxygen. This has caused sudden worker deaths, which is why ventilation and the STEL are so important for MC work in enclosed areas.

When is methylene chloride medical surveillance required?

Under 1910.1052(j), medical surveillance must be provided to employees exposed at or above the 12.5 ppm action level for 30 or more days a year, or above the PEL or STEL for 10 or more days a year, and to workers with signs or symptoms of overexposure. It focuses on the cardiac and other effects of MC and its carbon-monoxide metabolite.

What operations use methylene chloride?

Common uses include paint and coating stripping (including furniture and bathtub refinishing), metal degreasing and cleaning, adhesives and sealants, aerosol products, and pharmaceutical and chemical manufacturing. Any of these can exceed the OSHA limits without adequate ventilation, so 1910.1052 applies wherever methylene chloride is used and workers can be exposed.

Regulatory history of 29 CFR 1910.1052

OSHA issued the methylene chloride standard in 1997 (62 FR 1494), lowering the PEL to 25 ppm and adding the STEL, monitoring, and medical surveillance after documenting cancer risk and a pattern of sudden deaths, particularly in bathtub refinishing, caused by MC's metabolism to carbon monoxide in confined spaces.

Related glossary terms

Key terms that appear in 29 CFR 1910.1052, each with a full plain-English explainer.

Permissible Exposure Limit (PEL)Action LevelMedical SurveillanceEngineering ControlsRespiratory Protection ProgramSafety Data Sheet (SDS)

Related guides & articles

Workplace Chemical Exposure Limits: PEL vs TLVOSHA Chemical Storage Requirements Complete Guide

Related OSHA standards

29 CFR 1910.1000

Air Contaminants / PELs

29 CFR 1910.1001

Asbestos (GI)

29 CFR 1910.1003

OSHA 13 Carcinogens

29 CFR 1910.1018

Inorganic Arsenic

Primary sources

OSHA figures on this page are imported from HazComFast's verified regulatory module (verified 2026-10-05 against eCFR, OSHA.gov, and the Federal Register).

This page is an educational summary, not legal advice. OSHA standards and penalty amounts change; confirm requirements against the current regulation and your applicable State-Plan before acting.

Get the Binder in Order Before the Inspector Arrives. Are You Ready?

OSHA does not give advance notice of inspections (29 CFR 1903.6). Get the binder in order before the opening conference, not during it.

Serious Violation

$16,550

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