Methyl chloride

CAS: 74-87-3

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RTECS: N/A

OSHA PEL (8-hr TWA) 2 ppm OSHA PEL: See Annotated Z-2 ppm / See Annotated Z-2 mg/m3

NIOSH REL 2 ppm 0 ppm

IDLH Threshold 20 ppm Imm. Dangerous to Life/Health

Skin Hazard Notation No Dermal standard 29 CFR 1910

Interactive Engine

Methyl chloride Shift Exposure & PPE Compliance Calculator

Input your measured workplace air sample concentration and work shift schedule. The engine applies the Brief & Scala mathematical reduction model to determine legally defensible compliance.

Measured Air Concentration (ppm)

ppm

Work Schedule / Shift Duration

OSHA Compliance Determination Awaiting Sample Input

Adjusted PEL (Brief-Scala)

Hazard Ratio (HR)

Mandated APF Respirator

Enter an air sampling concentration above to evaluate whether your facility triggers the OSHA Action Level (0.5× PEL) or requires mandatory respiratory protection under 29 CFR 1910.134.

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Generates an instant 1-page OSHA 29 CFR 1910.1000 compliance record.

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NIOSH Respirator & Barrier Protection Specifications

Required Cartridge / Filter Acid Gas (Yellow/White)

Certified for concentrations within permissible limits.

Chemical Barrier Gloves Nitrile or Neoprene Chemical Barrier

Prevents transdermal permeation.

NIOSH Respiratory Protocol:

Mandatory NIOSH-approved Acid Gas (Yellow/White) required when airborne concentration exceeds action level under OSHA 29 CFR 1910.134.

Respirator Equipment Buy Acid Respirator

Dermal Barrier Chemical Barrier Gloves

B2B Industrial Supply Grainger Cartridge Catalog

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Frequently Asked Questions About Methyl chloride Exposure

What is the legal OSHA PEL for Methyl chloride?

Under OSHA 29 CFR 1910.1000 Table Z-1, the 8-hour Time-Weighted Average (TWA) Permissible Exposure Limit (PEL) for Methyl chloride (CAS 74-87-3) is 2 ppm. In addition, NIOSH recommends a Recommended Exposure Limit (REL) of 2 ppm.

How do extended 10-hour and 12-hour shifts affect Methyl chloride exposure limits?

Because OSHA PELs are formulated for 8-hour workdays, working 10-hour or 12-hour shifts reduces recovery time. Applying the standard Brief & Scala mathematical model reduces the allowable concentration by a Reduction Factor (RF = 0.700 for 10-hr, RF = 0.500 for 12-hr). For Methyl chloride, an 8-hr PEL of 2 ppm adjusts to half that value on a 12-hour shift.

What respirator and PPE is required when handling Methyl chloride?

When atmospheric concentrations exceed the permissible limit up to 10× PEL, OSHA 29 CFR 1910.134 mandates a half-mask elastomeric respirator equipped with Acid Gas (Yellow/White). For dermal exposure, Nitrile or Neoprene Chemical Barrier are recommended.

What is the IDLH threshold for Methyl chloride?

The Immediately Dangerous to Life or Health (IDLH) concentration established by NIOSH for Methyl chloride is 20 ppm. Any entry into atmospheres at or above this concentration requires positive-pressure supplied air or Self-Contained Breathing Apparatus (SCBA).

🔬 Related Chemicals Requiring Acid Gas (Yellow/White)

1,1,1,2-Tetrachloro-2,2-difluoroethane CAS 76-11-9 1,1,1-Trichloroethane; see Methyl chloroform CAS N/A 1,1,2,2-Tetrachloro-1,2-difluoroethane CAS 76-12-0 1,1,2,2-Tetrachloroethane CAS 79-34-5 1,1,2-Trichloro-1,2,2-trifluoroethane CAS 76-13-1 1,1,2-Trichloroethane CAS 79-00-5

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