I am not sure who, where, and when this dirty little lie began, but we have been seeing an incorrect application of NFPA 70, 500.7(K) Detection System for Flammable Gases, item (3) Interior of a Building or Enclosed Space. It seems businesses are looking for any way out of having an electrically classified area and many are using this “out”; however, most of the time we find its application is woefully incorrect. First, let’s look at this option: