This is the common UL and ULC Standard for Dry Chemical Fire Extinguishers. It is the third edition of CAN/ULC-S504, and the eleventh edition of UL 299.

These requirements cover the construction and performance, exclusive of performance during fire tests, of portable dry chemical and dry powder (Class D) fire extinguishers. Dry chemical and dry powder fire extinguishers are intended to be utilized in accordance with the Standard for Portable Fire Extinguishers, ANSI/NFPA 10 and with the National Fire Code of Canada.

The requirements for performance during fire testing of dry chemical fire extinguishers are specified in the Binational Standard for Rating and Fire Testing of Fire Extinguishers, ANSI/UL 711/CAN/ULC-S508.