Powder fire extinguishers must state their suitability for use on live electrical equipment, for example: suitable for use on live electrical equipment up to 1000 v at a distance of one meter. Remembering that powders can damage equipment and machinery. This is vital in an Aptitude Test For Firefighters.
It is emphasized that the use of powder extinguishers against class F fires (fires that affect cooking equipment) are considered dangerous. It is good to remember that once the fire has been extinguished it is advisable to ventilate the room, as, in addition to the combustion products (CO, CO2, various acids and gases, presence of powders not burned in the air) the same extinguishing powder, very fine can be inhaled together with other dangerous substances by the operator.
CO2 extinguishers (carbon dioxide) are structurally different from others because they consist of a steel cylinder made of a single piece of thickness suitable for internal pressures, valve unit with conical connection and without hole for pressure gauge connection or pressure control valve.
Extinguishers are certainly the primary means of intervention most used to extinguish the principles of fire, but they are not effective if the fire is in a more advanced phase. With regard to these means of fire protection, the document indicates that the extinguishers, which are classified according to their extinguishing capacity in relation to the various classes of fire can also be divided according to their total weight.
In particular, this type of fire extinguishers have the same characteristics as portable fire extinguishers, but due to their greater size and weight, less practical use and easier handling associated with moving the support cart. However, they have a greater extinguishing capacity (in the case of powder fire extinguishers, laptops have a charge of 1 to 12 kg, while wheeled vehicles from 30 to 150 kg) and are to be considered integrative of portable ones.
It is distinguished from other fire extinguishers also for the colors of the ogive (light gray, although not mandatory) and the diffuser of truncated-conical shape. The gas of these fire extinguishers surrounds the inflamed bodies, lowers the concentration of oxygen and extinguishes by suffocation and cooling.
The range is limited and it is therefore necessary to get as close as possible to the outbreak, using personal protective equipment. Generally, the distance of the jet is no more than two meters. This knowledge is tested in an Aptitude Test For Firefighters.
After pointing out that the CO2 that comes out of a fire extinguisher can cause cold burns, the document indicates that these fire extinguishers can be used on class B, C fires and electrical panels and equipment up to 1000 V.
