Solids or liquids light enough to be suspended in air.

Disease-producing microorganisms or materials.

Permissible Exposure Limits (standards set by OSHA), workplace exposure limits established to protect on-the-job workers.

A term used to describe the hydrogen ion activity of a water system. A solution of pH 0 to 7 is acid, pH of 7 is neutral, pH 7 to 14 is alkaline.

An air compartment connected to a duct or ducts.

Preventive Maintenance

Recommendations defining responsibility and action.

The routes followed by a pollutant from its emission (source) as it travels through a strucducts, air streams, etc.

3rd division of the C.N.S.

A flu-like illness caused by Legionnella or a similar bacterium named after a 1968 outbreak in Pontiac, Michigan.