What is the requirement for explosion proof lighting in a spray booth?

OSHA says that an employer must determine if the booth is a hazardous location per 1910.307. The definitions for the hazardous locations are found at 1910.399. If it is determined that the booth is a hazardous location, all lighting and other electrical devices must be “intrinsically safe” for that location, and be so marked. According the NFPA 33, “Standard for Spray Application Using Flammable or Combustible Materials,”non-intrinsically safe fixtures must be ate least 10 feet vertically and 20 feet horizontally from a Category I or II hazard.