How often must CO2 portable extinguishers undergo hydrostatic testing?

CO2 portable extinguishers must undergo hydrostatic testing every 5 years to ensure their structural integrity and safe operation. This testing is crucial because over time, the high-pressure cylinder that contains the CO2 can develop weaknesses or defects that may not be visible during regular inspections. Hydrostatic testing involves filling the cylinder with water and pressurizing it to detect leaks, bulges, or other failures that could lead to catastrophic failure if the extinguisher is used in an emergency. By adhering to this 5-year testing requirement, owners can be confident that their extinguishers are in proper working condition and safe to use when needed.