We have a project that has Class III liquids in Non-metallic IBC (Intermediate Bulk Containers).

NFPA 30 Tables 16.5.2.9 and 16.5.2.10 list storage requirements for Class III liquids in Nonmetallic IBCs. Stacked IBCs are limited to two-high (~8 feet), and in racks, only single and double row racks are allowed.

Under Section 12.8, these containers may be protected as "high storage of Class IV commodities" through NFPA 13, provided that the volume is limited to 13,750 gal (Class IIIB).

Does this mean that under NFPA 13, IBCs can be stacked up to 40-feet with 45-feet ceilings as per Table 23.3.1, or in multiple-row racks up to 40-feet high with 45-feet ceilings as per Table 23.5.1?

Or similar configurations as per Chapter 22 (CMSA)?

Provided the volume limit is not exceeded, of course.

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NFPA 30 Figure 16.2.5 is used to determine if a material is viscous liquid or not.

I am having an issue with a interpretation of the "Weight (percent flammable or combustible liquid)".

Is this weight for the liquid only or the liquid plus the container?

Example: Total package / container weight = 2.48 grams. The liquid inside is a Class III-A mixture that is 0.78 grams (31.5%).

If I go with the entire package Figure 16.2.5 is applicable (less than 50%), but if I am just looking at percent of combustible liquids, all the liquid is combustible.

Thanks in advance. 

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I have a question regarding the need to provide electrical classification for a building using Class 1A flammable liquids.

For this building, 4 gallons could be out in use (located anywhere in the building). The MAQ is 10 gallons. I have discussed this with NFPA 30 committee, the manufacturer, and the AHJ (who is a knowledgeable FPE). They have all determined that even if the MAQ is not exceeded, electrical classification is required if a flammable/explosive mixture could be present.

The NFPA 30 staff directed me to a provision in NFPA 497, Section 5.5, that if the materials will not reach 25% of the lower flammable limit (LFL), this could be utilized to justify not providing classified electrical fixtures.

Does anyone know how to do this calculation, or know of firms that can be hired to do this?

I am an FPE and do not know how to perform it, and I have spoken with other FPE’s who also are not aware. The gentleman I spoke with at NFPA 30 agreed it would be by an industrial hygienist or a chemical engineer and not an FPE.

But does anyone know any that can be hired for a one-off calculation, or have a place where I could learn how to perform it myself (NFPA reference, SFPE article, course, etc.?).

Thank you!

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