Fire Extinguisher FAQ

No. The chemicals in each type of fire extinguisher are unique and incompatible with each other.

Mixing them could potentially create a dangerous increase in pressure within the fire extinguisher that could cause the cylinder to fail and or rupture.
All stored pressure dry chemical fire extinguishers need to be recharged when any of the following situations occur:
  1. When the extinguisher has been used - even partially.
  2. When the pressure gauge indicates that the pressure has fallen below the operable range.
  3. When the weight of the extinguisher is below the minimum allowable gross weight for as listed on the name plate.
  4. When the extinguisher is opened for any type of maintenance or hydro static testing.
  5. When indicated by any type of inspection
Yes. Since the valve assembly needs to be removed during the recharging process a Verification of Service Collar is required to be installed around the neck of the fire extinguisher.

This is to ensure to the customer that the proper work has been preformed and that the extinguisher was actually disassembled as required in order to preform the recharge, 6 year maintenance or hydro static test.
It is the owners’ responsibility to inspect the fire extinguishers at a minimum of thirty day intervals. Fire extinguishers shall be inspected at more frequent intervals when circumstances require.

Fire extinguishers shall be subjected to maintenance at intervals of not more than 1 year, at the time of hydrostatic test, or when specifically indicated by an inspection or electronic notification.

Maintenance Record Keeping: Each fire extinguisher shall have a tag or label securely attached that indicates the month and year the maintenance was performed, identifies the person performing the work, and identifies the name of the agency performing the work.
Class K combustible cooking media fires typically involve kitchen appliances containing quantities of cooking greases or oils that present special hazard extinguishment and re-flash concerns.

Only Class K extinguishers have the ability to create a thick, heavy, long-lasting type of foam blanket on the hot cooking media surface to seal out the oxygen, cool the cooking media, and keep these fire situations out. The Class K listed fire extinguishers have effectively demonstrated the ability to address these commercial kitchen types of fire hazard situations.
Existing dry chemical extinguishers without a Class K listing that were installed for the protection of Class K hazards shall be replaced with an extinguisher having a Class K listing when the dry chemical extinguishers become due for either a 6-year maintenance or hydrostatic test.

Class K fire extinguishers shall be provided for hazards where there is a potential for fires involving combustible cooking media (vegetable or animal oils and fats).
No. Even a small discharge of your fire extinguisher will lower the pressure of the propellant enough to prevent another discharge or continue to allow the pressure to escape from the cylinder.

In many cases you can easily determine if your fire extinguisher has enough pressure by checking the gauges. Look for the arrow to be pointing to the green section to determine if it’s charged and ready to work properly in putting out a fire.

Even if you’ve only discharged your fire extinguisher a little, it needs to be serviced, recharged or replaced immediately.
Pressure testing of a fire extinguisher cylinder to verify its strength against unwanted rupture. If the cylinder is a DOT cylinder, this service must be performed by a facility that is approved by the D.O.T. to requalify cylinders.
An internal examination of an emptied dry chemical fire extinguisher to check for corrosion and any interior problems.

Extinguishers that pass the six year maintenance are then recharged, reassembled, and receive a six year service label and a verification of service collar.
NFPA 10 requires that:

Fire extinguishers having a gross weight not exceeding 40 pounds shall be installed so that the top of the fire extinguisher is not more than 5 feet above the floor.

Fire extinguishers having a gross weight exceeding 40 pounds shall be installed so that the top of the fire extinguisher is not more than 3 1/2 feet above the floor.

In no case shall the clearance between the bottom of the fire extinguishers and the floor be less than 4”.