The efficiency of the fire extinguisher must be checked every six months through specific technical checks. This phase of maintenance is called periodic inspection. This is why a professional maintenance technician is needed for these activities.

The physical condition of the fire extinguisher and its components must also be checked. For example, in the control phase the internal pressurization conditions are ascertained.

This phase is regulated by law, both for the project that must be carried out and for the periodicity. It must be performed by a competent person, with a maximum frequency of six months. By the end of the sixth month, it is necessary to check the efficiency of all types of portable or wheeled fire extinguishers, without carrying out function tests.

It consists of an activity aimed at verifying, with a maximum periodicity of 6 months (by the end of the month in question) the efficiency of portable and wheeled fire extinguishers by means of:

a) Verifications referred to in the surveillance phase

b) For pressurized fire extinguishers with permanent pressure, internal pressure control with an independent pressure gauge

c) For carbon dioxide extinguishers, checking the state of charge by weighing

d) For extinguishers with auxiliary gas (internal and/or external cylinder) cylinder charge control by weighing.

e) The extinguisher does not show anomalies such as clogged nozzles, pressure losses, traces of corrosion, disconnection or cracks in the flexible hoses.

f) The support is free from damage and the transport handle in particular, if on wheels, has working wheels

g) Is free from damage and dents to the tank.

h) The instruments used for the checks (manometers and scales) must be calibrated and/or verified, at specified intervals, or before their use, against standard measuring instruments.

Records of calibration and verification results must be maintained.

Any anomalies found must be eliminated immediately, otherwise, the fire extinguisher must be declared unsuitable by placing a "EXTINGUISHER OUT OF SERVICE" label on the appliance, also informing the responsible person and reporting "OUT OF SERVICE" on the maintenance tag.