The UL 142 standard for steel aboveground tanks for flammable and combustible liquids is one of the most common construction standards for the tank industry. One type of tank covered under this standard is the single wall storage tank. Underwriters laboratories (UL) is an accredited developer of standards for product safety and performance. UL standards are widely recognized in the United States and Canada across many industries. UL certified or listed means that UL has tested product samples and determined that it meets UL’s nationally recognized standards for safety. A UL product listing or certification demonstrates the manufacturer’s experience in the industry, the commitment it makes to quality and steps it has taken to ensure its products can be safely used. There is no legal requirement that all tanks must be UL certified or listed. However, the regulating authority or fire marshal may set such requirements in their jurisdiction.