Know the facts when fighting fire

Gloria Hafemeister
Now Media Group


Winter is a good time to review safety practices on the farm, not only to comply with OSHA rules on larger farms, but to keep everyone safe on farms of all sizes.

Safety supplies, equipment availability and safety training are important for all farms. Workplace fires and explosions kill hundreds and injure thousands of workers each year.

One way to limit the amount of damage due to such fires is to make portable fire extinguishers an important part of a fire prevention program.

Having adequate numbers of fire extinguishers readily available throughout the farm is part of a good safety plan, but just as important is training people on the farm how to use them.

'When used properly, fire extinguishers can save lives and property by putting out a small fire or controlling a fire until additional help arrives,' said Joseph Hertel, environmental coordinator for Fie and Life Safety at the University of Wisconsin-Madison.

Hertel and his staff are in charge of fire safety practices and equipment on the University of Wisconsin campus, including at the Arlington Research farm. Among his duties are annually inspecting the 13,000 fire extinguishers located throughout the university system's buildings. He also does fire extinguisher installations and removals; hands on-training for using them; and regular inspections on campus.

Hertel pointed out that a fire is the most common type of emergency for which small businesses, including farms, can plan.

'A critical decision when planning,' he said, 'is whether or not employees should fight a small fire with a portable fire extinguisher or simply evacuate.

'Don't think you have to grab an extinguisher and fight the fire. Think of your safety first. If you decide not to fight the fire, leave the building and close the door. Then call for help.'

First response

Hertel outlined some common-sense steps to follow when responding to a fire that is just developing:

✔Sound the fire alarm, and call the fire department, if appropriate.

✔Identify a safe evacuation path before approaching the fire. Do not allow the fire, heat or smoke to come between you and your evacuation path.

✔Select the appropriate type of fire extinguisher.

✔Discharge the extinguisher within its effective range using the P.A.S.S. technique (pull, aim, squeeze, sweep).

✔Back away from an extinguished fire in case it flames up again.

✔Evacuate immediately if the extinguisher is empty and the fire is not out.

✔Evacuate immediately if the fire progresses beyond the incipient stage.

During a recent training session for workers at the University's research farms in Arlington, he demonstrated proper techniques for using a fire extinguisher and then allowed each of the workers to try their hands at extinguishing a fire.

Proper operation

Most fire extinguishers operate using the following P.A.S.S. technique.

PULL. Pull the pin. This will also break the tamper seal.

AIM.Aim low, pointing the extinguisher nozzle (or its horn or hose) at the base of the fire. NOTE: Do not touch the plastic discharge horn on CO2 extinguishers; it gets very cold and may damage skin.

SQUEEZE.Squeeze the handle to release the extinguishing agent.

SWEEP. Sweep from side to side at the base of the fire until it appears to be out. Watch the area. If the fire reignites, repeat the procedure.

If you have the slightest doubt about your ability to fight a fire, evacuate immediately.

Types of extinguishers

Portable fire extinguishers apply an extinguishing agent that will cool burning fuel; displace or remove oxygen; or stop the chemical reaction so a fire cannot continue to burn. When the handle of an extinguisher is compressed, the agent is expelled out of the nozzle.

All portable fire extinguishers must be approved and labeled to identify the type and size fire it will extinguish.

The ABC Dry chemical extinguisher contains from 5 to 20 pounds of monoammonium phosphate, a finely-ground extinguishing agent that looks like yellow talcum powder. Nitrogen gas is used for propellant.

It is particularly effective for Class A, B and C fires, but it is extremely messy. It is used for ordinary combustibles, flammable liquids or electrical equipment.

Operation is fairly simple. Pull the pin through the seal, aim the extinguisher at the base of the fire and sweep from side to side. It has a range of about 15 feet.

The carbon dioxide extinguisher is a high- pressure vessel filled with either 5 or 10 pounds of liquid carbon dioxide. It is only to be used on flammable liquid or electrical fires. Because the carbon dioxide is expelled as a gas, the extinguisher has a very limited operation range of about 4 to 6 feet. It can be easily identified because it does not have a pressure gauge.

Carbon dioxide is not recommended for class A fires like wood, paper, cloth, rubber and certain plastics because they may continue to smolder and reignite after the carbon dioxide dissipates. Never use carbon dioxide extinguishers in confined space while people are present without proper respiratory protection.

Fires involving powders, flakes or shavings of combustible metals such as magnesium, titanium, potassium and sodium require special extinguishers labeled D.

Kitchen fires involving combustible cooking fluids such as oils and fats require a Class K extinguisher. It's a fairly new type of extinguisher because many of the newer vegetable oils have a higher heating rate. Once a fire starts in a deep fryer, it cannot always be extinguished by traditional range hoods or class B extinguishers.

Never use a Class A extinguisher containing water or carbon dioxide on a fat fryer fire. An explosive type reaction may result.

In fact, never use water to extinguish any flammable liquid fires. Water is extremely ineffective at extinguishing this type of fire and may make matters worse by the spreading of the fire.

In addition, never use water to extinguish an electrical fire. Water is a good conductor and may lead to electrocution if used to extinguish an electrical fire. Electrical equipment must be unplugged and/or de-energized before using a water extinguisher on an electrical fire.