Talking in Code: Combustible liquid indoor storage tanks
Want to know more about roof truss failures? Have a question about fire-rated assemblies? Confused about safety glazing on windows and door? In our monthly column — Talking in Code — International Code Council code experts will address some of the typical questions asked of our technical services team regarding current code issues. This feature is not an ICC code opinion, nor is it a committee interpretation, but it is intended to provide clarification of code text for adopting jurisdictions, design professionals and members of the construction industry.
International Code: 2015 International Fire Code
Question: Is secondary containment required for indoor storage tanks of Class IIIB combustible liquids?
Answer: In general, as indicated in Table 5004.2.2 for required secondary containment, the table defers to Chapter 57 for flammable and combustible liquids to determine whether secondary containment as specified in Section 5004.2 is required. Therefore, literally, unless a specific provision as specified in Chapter 57 referred back to Section 5004.2, the specific provisions of Section 5004.2 would not be applicable.
While Section 5703.4 refers back to Section 5004.2, it literally applies when the “maximum allowable quantity per control area” (MAQ) is exceeded. The apparent conundrum exists because a specific MAQ per control area is not established for Class IIIB combustible liquids in Table 5003.1.1(1) since note “f” of Table 5003.1.1(1) allows an unlimited quantity of Class IIIB liquids in a fully sprinklered building without warranting a Group H occupancy classification.
With that being said, the text of Section 5703.4 is clear that spill control and secondary containment are only required for the storage and use of Class IA, II and IIIA liquids when in excess of the maximum allowable quantity per control area. As such, there is no mandatory spill control and secondary containment required for Class IIIB combustible liquids.
As always, code opinions issued by International Code Council staff are based on published Code Council codes and do not include local, state or federal codes; policies; or amendments. This opinion does not imply approval of an equivalency, specific product, specific design or specific installation and cannot be published in any form implying such approval by the International Code Council. As this opinion is only advisory, the final decision is the responsibility of the designated authority charged with the administration and enforcement of this code. All code citations reference the 2015 and 2018 International Codes unless otherwise specified.