LEV systems are designed to remove hazardous substances from the workplace environment.
There are three types of contaminant: gases, vapours and particulates:
GAS - a substance that does not exist as a solid or liquid at normal room temperature and pressure (e.g. sulphur dioxide)
VAPOUR - the gaseous phase of a substance that usually exists as a solid or liquid at normal room temperature and pressure (e.g. solvent vapour)
