Combustible vs. Flammable Liquid Area Classification

alan232

Member
Location
Louisville, KY
I am looking at the SDS for a waste material that lists the flash point between 101-140°F, which, per NFPA 497 is a Class II Combustible Liquid. This material is being unloaded into a receiving tank, then pumped from the receiving tank to the process. I'm a bit perplexed on how to handle the area classification around the receiving tank. If it were a flammable liquid, it would be pretty clear to me. But, if it's a combustible liquid and handled below its flash point, is there no hazardous classification? If it's a combustible liquid handled above it's flash point, would the area classification be the same as if it were a flammable liquid? Wondering if anyone has run into this before. Thank you!
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
I am looking at the SDS for a waste material that lists the flash point between 101-140°F, which, per NFPA 497 is a Class II Combustible Liquid. This material is being unloaded into a receiving tank, then pumped from the receiving tank to the process. I'm a bit perplexed on how to handle the area classification around the receiving tank. If it were a flammable liquid, it would be pretty clear to me. But, if it's a combustible liquid and handled below its flash point, is there no hazardous classification? If it's a combustible liquid handled above it's flash point, would the area classification be the same as if it were a flammable liquid? Wondering if anyone has run into this before. Thank you!
Your basic reasoning is sound. You may want to review NFPA 497, Part 4.2.7.1 for a little more analysis.

At the moment, CMP14 and most other NFPA Technical Committees (TC) "punt" regarding random/temporary ambient temperature excursions that may occur above a material's flash point. A few CMPs refer to the ASHRAE Handbook of Fundamentals.
 

alan232

Member
Location
Louisville, KY
Your basic reasoning is sound. You may want to review NFPA 497, Part 4.2.7.1 for a little more analysis.

At the moment, CMP14 and most other NFPA Technical Committees (TC) "punt" regarding random/temporary ambient temperature excursions that may occur above a material's flash point. A few CMPs refer to the ASHRAE Handbook of Fundamentals.
Thank you for the reply and insight.
 
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