Regulations (Preambles to Final Rules) - Table of Contents Regulations (Preambles to Final Rules) - Table of Contents
• Record Type: Occupational Exposure to Methylene Chloride
• Section: 4
• Title: Section 4 - IV. Chemical Identification

IV. Chemical Identification

Methylene chloride (MC), also called dichloromethane (DCM) [Chemical Abstracts Service Registry Number 75-09-2] is a halogenated aliphatic hydrocarbon with a chemical formula of CH(2)Cl(2), a molecular weight of 84.9, a boiling point of 39.8 deg. C (104 deg. F) at 760 mm Hg, a specific gravity of 1.3, a vapor density of 2.9 and a vapor pressure of 350 mm Hg at 20 deg. C (68 deg. F). Concentration of MC in saturated air at 25 deg. C reaches 550,000 ppm. MC has low water solubility (1.3 gm per 100 gm of water at 20 deg. C), an extensive oil and fat solubility, and a low flammability potential. It is used as a flame suppressant in solvent mixtures (lower explosive limit of 12% and upper explosive limit of 19%). It is a colorless volatile liquid with a chloroform-like odor and its odor threshold varies between 100 and 300 ppm. Contact with strong oxidizers, caustics and active metal powder may cause explosions and fires. Decomposition products during combustion or fire include phosgene, hydrogen chloride and carbon monoxide.

[62 FR 1494, January 10, 1997]
Regulations (Preambles to Final Rules) - Table of Contents Regulations (Preambles to Final Rules) - Table of Contents