Environmental Health and Safety

MSDS Glossary

m
Meter is a unit of length in the metric system. One meter is about 39 inches.
m3
Cubic meter is a metric measure of volume, approximately 35.3 cubic feet or 1.3 cubic yards.
Malaise
A feeling of general discomfort, distress, or uneasiness, an out-of-sorts feeling.
Mechanical Exhaust
A powered device, such as a motor-driven fan or air steam venturi tube, for exhausting contaminants from a workplace, vessel, or enclosure.
Mechanical Filter Respirator
A respirator used to protect against airborne particulate matter like dusts, mists, metal fume, and smoke. Mechanical filter respirators do not provide protection against gases, vapors, or oxygen deficient atmospheres.
Melting Point
The temperature at which a solid substance changes to a liquid state.
Metabolism
Physical and chemical processes taking place among the ions, atoms, and molecules of the body.
Meter
A unit of length, equivalent to 39.37 inches.
mg
Milligram is a metric unit of weight that is one-thousandth of a gram, i.e. 1000 milligrams equals one gram.
mg/kg
Milligrams of substance per kilogram of body weight is an expression of toxicological dose.
mg/m3
Milligrams per cubic meter is a unit for expressing concentrations of dusts, gases, or mists in air.
Micron (Micrometer)
A unit of length equal to one-millionth of a meter; approximately 0.000039 of an inch.
Mist
Suspended liquid droplets generated by condensation from the gaseous to the liquid state, or by breaking up a liquid into a dispersed state, such as splashing, foaming, or atomizing. Mist is formed when a finely divided liquid is suspended in air.
Mixture
Any combination of two or more chemicals.
ml
Milliliter is a metric unit of capacity, equal in volume to 1 cubic centimeter (cc), or approximately one-sixteenth of a cubic inch. One-thousandth of a liter.
mmHg
Millimeters (mm) of mercury (Hg) is a unit of measurement for low pressures or partial vacuums.
Molecular Weight
Weight (mass) of a molecule based on the sum of the atomic weights of the atoms that make up the molecule.
MSDS
Material Safety Data Sheet, a document containing information and instructions on the chemical and physical characteristics of a substance, its hazards and risks, safe handling requirements and the actions to be taken in the event of fire, spill or exposure.
Mutagen
A substance or agent capable of altering the genetic material in a living cell. See also Reproductive Toxin.
MW
See Molecular Weight.

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