Which kind of extinguisher should I use? While it continues to mri protocols and planning pdf laboratories, the information contained herein is broadly applicable to almost all workplaces.
Fire is the most common serious hazard that one faces in a typical chemistry laboratory. Class B fires involve flammable or combustible liquids such as gasoline, kerosene, and common organic solvents used in the laboratory. Class C fires involve energized electrical equipment, such as appliances, switches, panel boxes, power tools, hot plates and stirrers. Water can be a dangerous extinguishing medium for class C fires because of the risk of electrical shock unless a specialized water mist extinguisher is used.
Class D fires involve combustible metals, such as magnesium, titanium, potassium and sodium as well as pyrophoric organometallic reagents such as alkyllithiums, Grignards and diethylzinc. Class K fires are kitchen fires. This class was added to the NFPA portable extinguishers Standard 10 in 1998. Kitchen extinguishers installed before June 30, 1998 are “grandfathered” into the standard. Halotron and those hard-to-find Class D models.
Everything from small hand-held units to large wheeled units and fixed distribution systems. If you need 1 extinguisher or 1,000 we can meet your needs! Some fires may be a combination of these! Your fire extinguishers should have ABC ratings on them. UL Standard 711 and look something like “3-A:40-B:C”. Higher numbers mean more firefighting power.
In this example, the extinguisher has a good firefighting capacity for Class A, B and C fires. They have an advantage over CO2 and “clean agent” extinguishers in that they leave a blanket of non-flammable material on the extinguished material which reduces the likelihood of reignition. They also make a terrible mess – but if the choice is a fire or a mess, take the mess! Type BC fire extinguishers contain sodium or potassium bicarbonate. Type ABC fire extinguishers contain ammonium phosphate. Dry chemical extinguishers can be quite corrosive to metals such as aluminum and are also potentially abrasive. Proper planning can avoid situations where you might have to make a choice between extinguisher types.
Carbon dioxide extinguishers do not have pressure gauges because carbon dioxide is a condensable gas. Thus, pressure does not tell you how much agent remains in the cylinder. To determine the amount of carbon dioxide remaining in the extinguisher, subtract the tare weight from the current weight. Heat from the fire causes the agent to cake and form a crust that excludes air and dissipates heat.
Developed in conjunction with the U. Navy, it is the only known lithium fire fighting agent which will cling to a vertical surface thus making it the preferred agent on three dimensional and flowing fires. Graphite-based powders are also designed for use on lithium fires. This agent can also be effective on fires involving high-melting metals such as zirconium and titanium. Specially-designed sodium bicarbonate-based dry agents can suppress fires with most metal alkyls, pyrophoric liquids which ignite on contact with air, such as triethylaluminum, but do not rely on a standard BC extinguisher for this purpose. This agent is recommended where stress corrosion of stainless steel must be kept to an absolute minimum. Halotron I extinguishers, like carbon dioxide units, are “clean agents” that leave no residue after discharge.
The FE-36 agent is less toxic than both Halon 1211 and Halotron I. FE-36 is not scheduled for phase-out wheras Halotron I production is slated to cease in 2015. Water mist extinguishers are ideal for Class A fires where a potential Class C hazard exists. Unlike an ordinary water extinguisher, the misting nozzle provides safety from electric shock and reduces scattering of burning materials. This is one of the best choices for protection of hospital environments, books, documents and clean room facilities. Check out the potential fire hazards in your area. Do you know how to operate it?
Are your extinguishers suitable for the fires you may encounter? If not, you’ll want to contact your campus or corporate Fire Marshal’s office. CO2 extinguisher provided that you are properly trained. The fire is small, contained and not spreading beyond its starting point.