Volatile Organic Compounds (VOCs) Volatile Organic Compounds are harmful, gaseous pollutants that are formed from products or processes in industrial or manufacturing applications and commonly contaminate groundwater. They have high vapor pressure and low water solubility. Most VOCs are carcinogenic and may react with other gases to form different air pollutants in the atmosphere. VOCs have an initial boiling point less than or equal to 250° C measured at a standard atmospheric pressure of 101.3 kPa. Hazardous Air Pollutants (HAPs) Hazardous Air Pollutants are contaminants that are known or suspected, to be carcinogenic or cause other serious health conditions. HAPs can cause reproductive effects or birth defects, neurological disorders, heritable gene mutations and other reversible chronic or acute health conditions, as well as adverse environmental effects.