NIOSH Pocket Guide to Chemical Hazards

Methylene chloride

CAS 75-09-2


RTECS PA8050000
Synonyms & Trade Names
Dichloromethane, Methylene dichloride
DOT ID & Guide
1593 160


NIOSH REL: Ca See Appendix A
OSHA PEL: [1910.1052] TWA 25 ppm ST 125 ppm
IDLH Ca [2300 ppm] See: 75092 Conversion 1 ppm = 3.47 mg/m3
Physical Description
Colorless liquid with a chloroform-like odor. [Note: A gas above 104°F.]
MW: 84.9
BP: 104°F
FRZ: -139°F
Sol: 2%
VP: 350 mmHg
IP: 11.32 eV

Sp.Gr: 1.33
Fl.P: ?
UEL: 23%
LEL: 13%

Combustible Liquid
Incompatibilities & Reactivities
Strong oxidizers; caustics; chemically-active metals such as aluminum, magnesium powders, potassium & sodium; concentrated nitric acid
Measurement Methods
NIOSH 1005, 3800; OSHA 59, 80
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet or contaminated
Change: No recommendation
Provide: Eyewash, Quick drench
First Aid (See procedures)
Eye: Irrigate immediately
Skin: Soap wash promptly
Breathing: Respiratory support
Swallow: Medical attention immediately
Important additional information about respirator selection
Respirator Recommendations (See Appendix E) NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin; lassitude (weakness, exhaustion), drowsiness, dizziness; numbness, tingle limbs; nausea; [potential occupational carcinogen]
Target Organs Eyes, skin, cardiovascular system, central nervous system

Cancer Site [in animals: lung, liver, salivary & mammary gland tumors]
See also: INTRODUCTION   See ICSC CARD: 0058   See MEDICAL TESTS: 0148