Extinguishers:  When they must be replaced?

Stored pressure dry chemical extinguishers (other than wheeled units) that were manufactured prior to October 1984 must be taken out of service per NFPA 10.  This mandate first appeared in the 2007 edition of the NFPA 10.  This requirement remains in the 2013 edition of NFPA 10 so that areas of the country that have not adopted the latest edition will retain that requirement for years to come.  NFPA 10 did allow for a phase-out of these extinguishers by mandating their removal the next six-year maintenance or 12-year hydrostatic test interval, whichever came first.

The listing standards for dry chemical extinguishers are UL 299 (construction) and UL 711 (fire testing).  Both were updated in 1984 with these 5 improvements relating to extinguisher operation.