UL 142 and CAN/ULC-S601: What Those Compliance References Mean

If you have looked at above-ground fuel storage, you have probably seen two references come up again and again: UL 142 and CAN/ULC-S601. They are standards for aboveground steel tanks for flammable and combustible liquids. Here is what each one covers and why buyers care.

UL 142

UL 142 is a widely recognized North American standard for aboveground steel tanks that store flammable and combustible liquids such as diesel. It sets requirements for tank construction, materials, and testing so that tanks built to it meet a consistent baseline for structural integrity and safe containment.

CAN/ULC-S601

CAN/ULC-S601 is the Canadian standard for shop-fabricated aboveground horizontal steel tanks for flammable and combustible liquids. In Canada, this is the reference authorities and insurers commonly expect for this class of tank, which is why it appears alongside UL 142 on equipment intended for the Canadian market.

Why double-wall matters here

Both standards relate to how a tank is built and tested. Double-wall construction adds a second physical barrier — secondary containment — so that if the primary tank is compromised, fuel is captured rather than released to the ground. On many industrial and commercial sites, secondary containment is expected or required, which is why every Hudson station is double-wall.

What this means for your project

Compliance is not just a sticker; it affects permitting, insurance, and your environmental liability. The exact requirements that apply to your installation depend on your jurisdiction, the authority having jurisdiction (AHJ), your fire code, and your insurer. Local rules can add requirements beyond the tank standard itself — for spacing, spill response, signage, and inspection.

If you want help understanding which references apply to a station for your location, contact us and we can point you in the right direction.

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