The brandy distillery didn't use grain at all, but the Alcohol content was high enough to trigger the need for Classification (Class 1 Div 2) in a 25' perimeter of the still and 3 feet above the floor in the building where the still was.
There are no specific codes and standards that cover the area classification of industrial facilities. Each has to be evaluated based on the potentials for flammable concentrations of vapors and the electrical installed based on that evaluation. The area classification is really more of a function of process and mechanical engineers as they more fully understand the potential for flammable concentrations.I'm looking at a small distillery with a small bar area in an adjacent room. There won't be any classification documentation unless I create it. I was wondering what codes or standards might apply, and my first internet search returned this:
NFPA Journal - Safe Distilling, Mar Apr 2018
As the craft distilling industry grows in the United States, concerns are mounting about how to better protect the facilities from fire and other hazards.www.nfpa.org
which pretty much confirmed my fear - there really aren't any codes or standards that fit the unique requirements of these micro-distilleries.
They will also look at the operating pressure and temperature as well as the if there are valves and other such process piping fittings that have an potential for leakage.Ultimately this will fall to the AHJ, and knowing what codes/standards are adopted in that area. I have done plenty of Hazardous areas designs/installations. There are companies that specifically do this type of study. Much of it surrounds parameters defined in NFPA 497, NFPA 30, and NFPA 499. I have seen one or two locals which incorporated ISA requirements rather than NFPA, but the majority default to NFPA.
Things such as flash point, ventilation, chemical composition, and specific gravity play into what classifies an area. If you are not thoroughly experienced with this kind of thing, and supported by a team who can do the required testing/analysis required then your position should be they need to have a study done.
One last word of caution: Some alcohol plants will fall back on DISCUS and documents provided by insurance companies. While these are considerations the customer needs to consider, they are not the determining factor. Ultimately that falls on the engineer and AHJ. In the case where you cannot convince yourself the area is not classified, and the customer refuses to pay for a study.... then the area is classified.