Final answer:
The only way to ensure an extinguisher's reliability is through regular inspection and maintenance, including professional servicing as required.
Step-by-step explanation:
The only way to confirm that an extinguisher is in proper working order and will operate reliably in an emergency is through regular inspection and maintenance. This typically includes checking for physical damage, ensuring the pin and tamper seal are intact, verifying that the pressure gauge shows a full charge, and inspecting the hose or nozzle for obstruction. Moreover, professional servicing by a certified technician is recommended regularly as specified by the manufacturer or regulatory guidelines. In laboratory settings, it's critical to know the location of fire safety equipment and to handle flammable chemicals with care to prevent accidents that might require the use of an extinguisher.