There are other factors besides alcohol percentage that are not, and probably should not, be explicitly considered by NFPA 13: temperature, container size, container type.
At elevated temperatures (e.g. a liquor store in Barstow, California during summer with the air conditioning off for a week), ethanol mixtures will be much more flammable and burn much quicker than the same liquor store in Ft. McMurray, Alberta during winter -- where the alcohol might be consumed quicker than it is burned. Another factor is the container size. Many smaller containers is arguably safer than one large container, from a maximum-likely fire size perspective. This is why Haz-Mat prescriptions are more lenient on occupancies with smaller containers. Another factor is, as Roland stated, size of the store. And its fire resistance. If it is a stand alone building with no close exposures, all the better. If it is CMU wall construction, great. If it is a store in a rustic Old West wood-sided strip mall with a nursery down the hall, not as good. Most of the alcohol is in containers that are 'fifths' or 1.5 L. Even at Las Vegas summer temperatures without air-conditioning, hottest temperature is still about 130 F, which is hot enough to ignite some mid-range proofs that otherwise would not burn at room temperature, but the burning of most mid-range ethanol mixtures is not overwhelming. Storage configuration matters too. In seismic zones, putting up wire restraints on the shelving to protect bottles from falling is a precaution not for fire safety per se, but to prevent breakage during earthquakes. I would approve OH-2, realizing that it will not stop all fires, but it will control greater than 85% of the historical fires in everyday liquor stores. If the AHJ wants faster extinguishment, given that extinguishing agent discharge will occur, then water is not the ideal agent for ethanol fires; foam is. But the reliability of proper foam system discharge is not as high as the reliability of wet-pipe sprinklers discharge, because of the slightly greater complexity of the foam system. We design for what is reasonable. This forum provides an invaluable tool in getting to 'what is reasonable' by providing open debate. Few want to portray themselves in public as reckless with fire safety, but posing one's arguments in public is the antithesis of reckless. The debate is often better when more opinions are offered. Scot Deal Excelsior Fire & Risk
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