I need clarification concerning the intergration of the international electrical codes and the use of electrical equipment in hazardous area classification according to the world standards and the NFPA/NEC american standards. I have been reading to many articles & codes, and I have spoken to too many organizations like UL, FM, OSHA, ANSI, Dept. of Commerce etc. concerning hazardous area classification and the use of electrical equipment in these areas. So far everybody has been providing me with BS without giving any clear direction. In 1996 the US accepted the world standard for classifying hazardous areas according to Zones, this in order to promote international trade. In stead of the codes and international trade getting easier everybody seems to make an effort in making things more complicated. For example, Class I, Zone 1 equipment has to comply with the same codes and standards as Class I, Division 1 equipment. Yet, according to UL you are not allowed to use Zone 1 equipment in Class I, Div 1 areas since Zone 0 is included in this hazardous area, referring to the NEC. However the 1999 NEC in article 500 only reads that you are allowed to use Zone 0, 1 and 2 equipment in Class I, Div 2 hazardous areas. It makes no mentioning that you are not allowed to use Zone, 0 or Zone 1 certified equipment in Class 1, Div 1 hazardous areas. Are the codes just there to prevent foreign companies to enter the US market? Are the just there to confuse everybody? Can anybody point me to the REAL codes and if possible clarify them for me?