Almost all of the recognized codes and standards related to the storage of flammable liquids will reference an Underwriters’ Laboratories construction standard, No. 142, Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids. Those recognized codes and standards include OSHA’s 1910.106, Flammable liquids and the International Fire Code (IFC). The IFC does not directly reference UL 142, but it does state that “the design, fabrication, and construction of tanks shall comply with NFPA 30” and NFPA 30 states:
(emphasis by me)
21.4.2.1 Design Standards for Atmospheric Tanks.
21.4.2.1.1* Atmospheric tanks shall be designed and constructed following recognized engineering standards. Atmospheric tanks that meet any of the following guidelines shall be deemed as meeting the requirements of 21.4.2.1:
(1) API Specification 12B, Bolted Tanks for Storage of Production Liquids
(2) API Specification 12D, FieldWelded Tanks for Storage of Production Liquids
(3) API Specification 12F, Shop Welded Tanks for Storage of Production Liquids
(4) API Standard 650, Welded Steel Tanks for Oil Storage so from an industrial use/storage of flammable liquids in above ground tanks
(5) UL 58, Standard for Steel Underground Tanks for Flammable and Combustible Liquids
(6) ANSI/UL 80, Standard for Steel Tanks for Oil-Burner Fuels and Other Combustible Liquids
(7) ANSI/UL 142, Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids
(8) UL 1316, Standard for Glass-Fiber Reinforced Plastic Underground Storage Tanks for Petroleum Products, Alcohols, and Alcohol-Gasoline Mixtures
(9) ANSI/UL 1746, Standard for External Corrosion Protection Systems for Steel Underground Storage Tanks
(10) UL2080, Standard for Fire Resistant Tanks for Flammable and Combustible Liquids
(11) ANSI/UL 2085, Standard for Protected Aboveground Tanks for Flammable and Combustible Liquids
Then we have OSHA’s language where UL 142 is referenced…
1910.106(b)(1)(iii)(a)(1) Underwriters’ Laboratories, Inc., Subjects No. 142, Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids, 1968; No. 58, Standard for Steel Underground Tanks for Flammable and Combustible Liquids, Fifth Edition, December 1961; or No. 80, Standard for Steel Inside Tanks for Oil-Burner Fuel, September 1963.
Often times when a business orders a tank for flammable liquids use, the business just states the tank must meet UL142 and an “off-the-shelf” tank is purchased based on specific needs (e.g. size). But as a safety professional, we should have a little bit of understanding as to what UL142 actually requires and why and just by good fortune UL has published a nice “cheat-sheet” for us… (emphasis by me)
1. Codes recognize the use of UL 142 listed tanks
The NFPA 30 Flammable and Combustible Liquids Code requires atmospheric tanks to be designed and constructed in accordance with one of several recognized engineering standards, one of which is the UL 142, Standard for Safety for Steel Aboveground Tanks for Flammable and Combustible Liquids. The International Fire Code, in turn, requires tanks to be designed, constructed and installed in accordance with NFPA 30.
2. Types of tanks covered by UL 142
UL 142 includes requirements that cover steel primary, secondary and diked type atmospheric storage tanks intended for noncorrosive, stable flammable and combustible liquids that have a specific gravity NOT exceeding 1.0 in ABOVEGROUND applications. UL 142 includes requirements for tanks fabricated in a combination of various shapes (cylindrical, rectangular or round) and orientations (horizontal, vertical) with or without multiple compartments.
UL 142 covers shop fabricated tanks ONLY, and does NOT cover portable tanks intended for transporting flammable or combustible liquids (such as shipping containers), or mobile use applications (such as mounted on a trailer).
3. UL 142 requirements
UL 142 includes requirements that manufacturers use to design and fabricate aboveground steel tanks, and that certification organizations such as UL use to investigate and List (certify) these tanks. The standard includes a comprehensive set of requirements in the following areas:
- Construction requirements – These include specification for the tank materials, joints, connections, fittings, manholes (if provided), fill, drain and gauge openings, and painting. They also include specific construction requirements for the primary and secondary containment means, supports, etc.
- Performance tests – These requirements include tank leakage, hydrostatic strength, top loading, buoyancy, hydrostatic load, tank support load, and lift lug tests that are designed to verify that the tank design does not exhibit signs of leakage and/or structural damage as a result of these tests.
- Markings and production line test – UL 142 requires tanks to include specific markings discussed below. In addition, 100% of the production of each Listed primary and secondary containment tank must be tested for leakage by the manufacturer.
4. Listing marks
Aboveground tanks that have been found to comply with applicable UL 142 requirements include a UL Listing Mark PERMANENTLY affixed to the container. The Listing Mark consists of the:
- UL symbol,
- the word “LISTED,”
- a control number and
- the name of the tank construction as indicated in the manufacturer’s Listings (e.g., Secondary Containment Aboveground Tank, Generator Base Tank, etc.)
5. Product categories
Information on tanks certified in accordance with UL 142 can be found in the Online Certifications Directory at www.ul.com/database. The guide information for the Aboveground Flammable-liquid Tanks (EEEV) product category includes useful information on the products covered under this category. In addition, the Special-purpose Tanks (EFVT) product category covers Listed UL 142 aboveground steel tanks that include generator base, work-top, lube oil, waste oil, day/utility and other special-purpose type tanks.
6. Features covered
The essential characteristics of tanks covered by the UL 142 Listing include all containment spaces and their respective openings (manways, emergency vents, standard vents, fill/withdraw, gauging, monitoring and other functional openings) with connections (threaded- or flanged-type fittings) and integral tank accessories such as ladders, stairs, lifting lugs and heating coils or hot wells. All primary-tank compartment(s) are provided with openings to accommodate filling, withdrawing and inventory control; and all secondary-tank interstitial spaces are provided with openings for leak-detection monitoring.
7. Features not covered
UL 142 tank Listings includes the features and accessories described above, which are described in the individual Listings. Any other accessories or components that are shipped with the tanks, attached to the tanks or added to the tanks are not included in the scope of the tank Listing. It is anticipated that the code authority will approve the use and/or installation of any such accessories independent of the tank Listing.
8. Venting and leak detection
All primary-tank compartment(s) are provided with standard and emergency vent openings. All secondary-tank interstitial space(s) are provided with emergency vent openings. It is anticipated that venting will be implemented at the actual installation in accordance with applicable code requirements.
9. Intended use
UL 142 Listed tanks are designed for installation in accordance with a variety of installation codes, including NFPA 30, NFPA 30A, NFPA 31, NFPA 37, NFPA 1 and the International Fire Code. They have NOT been investigated for use UNDERGROUND. However, they are suitable for use in UL 2245 Listed below grade vaults as allowed by the applicable installation code.
10. UL 80 Tanks
In comparison to UL 142, the UL 80 Standard for Steel Tanks for Oil-Burner Fuels and Other Combustible Liquids covers aboveground 60 to 660-gallon steel tanks intended for the storage of HEATING FUELS for oil burning equipment, diesel fuels for compression ignition engines and new and used motor oils at automotive service stations.
CLICK HERE to download UL’s cheat-sheet