United States: Mandatory regulations: NFPA 855 (Fire Safety Code), IFC (International Fire Safety Code), OSHA

Applicable standards: UL 9540, UL 1973, UL 9540A

Note: A mandatory requirement for grid connection, installation permits, and insurance coverage of energy storage systems; products without the UL mark cannot be legally sold.

Canada: Mandatory regulations: Canadian Electrical Code (CEC), provincial safety regulations

Applicable standards: cUL/ULC standards (mutually recognized with UL)

Note: Canada-US Mutual Recognition Agreement (MRA): UL-certified products can seamlessly enter Canada, and vice versa (CSA certification is also mutually recognized).

Key difference: In the United States, the UL 9540A test report is a required document for the Fire Safety Audit (AHJ), and is more critical than UL 1973.