Specifiers are increasingly citing requirements for equipment suitable for use in classified areas. When properly used, the hazardous area classification system makes for a safer work environment. Too often, however, hazard classes are specified without concern for the significantly higher design and procurement costs they bring. In many cases, an open mind and a little ingenuity can avoid excessive costs for compressors and other equipment, without compromising safety. This white paper explains hazardous classification systems commonly used and outlines considerations for installing compressed air equipment in these areas.