I would like to install equipment away from the hazerdous zone. Could someone tell me where in the code book if any is the distance away from class 1 div 1 location where it is considered nonhazerdous? This is an outside Tank Farm.
Your question is a bit too general - so for now I can only give a general answer.
Article 515 will be your Staring point. You have to establish what equipment or process creates the hazardous location in the first place. After that, then the "geometery" of the location will begin to influence the various zones. In your case, the type of tank construction and containment methods for leaks and spills.
The measurements are usually taken from the equipment or specific devices on the equipment creating the Class I location (tanks, relief valves, etc.) but containment will also affect it.
You have said it is outside, so there will also be a Division 2 area - possibly outside the containment.
In ALL cases documenting the electrical area classification is an NEC requirement [Section 500.4(A)]
Depending on the size of the equipment and nature of your facility, you may also want to consult NFPA 30, NFPA 497, or API RP500.