Acronym for Indoor Air Quality. EPA's Indoor Air Quality Information Clearinghouse (1-800-438-4318 or 301-585-9020).

When the body's natural defenses to infection are below normal.

Chemical compounds, such as carbon dioxide, whose presence at certain concentrations may be used to estimate certain building conditions (e.g., airflow, presence of sources).

Substances which inflame living tissue by chemical action at the site of contact, causing pain or swelling.