=== Under the right conditions, an electrical spark from a motor, a pump, from ball bearings rubbing together, or even from a light switch on a wall can set off an explosion. ===

Just for the record, an environment such as a sugar refinery falls under National Electrical Code Class II Division 1 - explosive dust present at all times. As such all electrical equipment (all the way down to pocket radios) should be certified for Division 1. The common term for Division 1 is "explosion proof" where the key word is "proof" (as opposed to a consumer-grade term such as "water _resistant_) and it should not only NOT produce sparks under normal operating conditions but should not produce sparks under any foreseeable single mode of failure ("fail-safe").

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