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SDS Terminology

Purpose: Use this job aid to learn about Safety Data Sheet (SDS) terminology.

It's important to learn abbreviations and terms commonly used on Safety Data Sheets (SDSs):

• flash point – Temperature at which a liquid will give off enough flammable vapor near the surface of the liquid to cause the material to ignite.
• solubility in water – A term expressing the percentage of a material that will dissolve in water.
• specific gravity – The weight per unit volume of a material compared to the weight of an equal volume of water.
• upper and lower explosive limits (UEL/LEL) – The highest and lowest concentration of a chemical that will explode if an ignition source is provided.
• vapor density – The relative weight of gases and vapors as compared to air. A material with a vapor density greater than one is heavier than air, and will gather along the floor. A material with a vapor density less than one is lighter than air and will rise.
• vapor pressure – The pressure exerted by a vapor on the walls of its container. The higher the vapor pressure, the more volatile the liquid.
• short term exposure limit (STEL) – The maximum exposure for a period no longer than 15 minutes.
• permissible exposure limit (PEL) – Exposure limits based primarily on the 1968 TLVs established and enforced by OSHA as law.
• threshold limit value (TLV) – The exposure amount considered safe by the American Conference of Government Industrial Hygienists (ACGIH) for employees over a working lifetime. Exposures above this level increase the risk of an adverse health effect.
• threshold limit value ceiling (TLV-C) – The concentration that shouldn't be exceeded during any part of the working exposure.
• time weighted average (TWA) – The exposure amount averaged over an eight-hour period.
• fifty percent of lethal dose (LD50) – The chemical dose that results in the death of 50% of humans or animals exposed within a specified time; most often given for rats.
• immediately dangerous to life and health (IDLH) – Airborne contaminant levels likely to cause death or immediate or delayed permanent adverse health effects, or prevent escape.
• parts per million (PPM) – A unit used to express concentration. Defines parts of the chemical in one million parts of air, water, or soil. To visualize this, imagine one red ball in a swimming pool full of one million white balls.
• milligrams per cubic meter (Mg/m3) – A unit used to express concentration. Defines the mass of chemical contaminant, in milligrams, allowed in each cubic meter volume of air. To visualize this, imagine a speck of sand in a cube of air measuring one meter tall by one meter wide by one meter deep.