How to identify Zone 1 areas (IS 5572) ?
- Flammable gas or vapour concentration is likely to exist in the air under normal operating conditions
- Flammable atmospheric concentration is likely to occur frequently because of maintenance, repairs or leakage
- Flammable liquid or vapour piping system (containing valves, meters, or screwed or flanged fittings) is in an inadequately ventilated area
- The area below the surrounding elevation or grade is such that flamamble liquids or vapours may accumulate therein