hazardous area

1. Within a building, an area which houses highly combustible, highly flammable, or explosive products or materials which are likely to burn with extreme rapidity or which may produce poisonous fumes or gases, including highly toxic or noxious alkalies, acids, or other liquids or chemicals, which involve flame, fume, explosive, poisonous, or irritant hazards.

2. Any area in which there are fine particles or dust subject to explosion or spontaneous combustion.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.