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Water as an Extinguishing Agent (it doesn’t always work!)

Water ExtinguisherFire departments use lots of water to fight fires.  The majority of fires can be extinguished with water.  As one alert citizen pointed you a while back, water isn’t always the best choice for putting a fire out.

There are several different classes of fires, and each is extinguished a little differently.

Class A fires are the average combustibles that you would find in a dumpster or garbage can.  Wood, paper, cardboard and textiles are fuels that generate Class A fires.  Water is a great extinguishing agent for these fires.  Most people think we’re drowning the fire with water and starving it for oxygen.  That’s not really the case.  Water absorbs a tremendous amount of heat, especially as it turns to steam.  Normally you extinguish Class A fires with water by removing the heat and putting the fire out.

Class B fires involve flammable liquids like gasoline, diesel fuel, alcohol and molten plastics.  These fuels are liquids and flammable vapors are given off at the liquid surface.  It is these vapors that burn, not the liquid.  If I leave the surface of the liquid pool calm and placid, the surface area is the smallest it can be.  If I stir that liquid surface up, I increase the surface area, the amount of flammable vapors released, and the amount of fire.  That’s one reason you don’t pour water on stove-top cooking oil fires.  Almost all successful Class B extinguishment is accomplished by starving the fire for oxygen.  On your stove-top you cover the cooking pot with the lid and starve flames for oxygen.  We cover gasoline spills with foam to exclude oxygen and extinguishing the fire.

Class C fires involve electrical current and you must approach these fires carefully!  If you extinguish the fire while electricity is still supplied, the fire will re-ignite.  Furthermore, water will conduct electricity from the source to you (electrocution).  That’s why you disconnect power before fighting a Class C fire.  An ABC fire extinguisher helps as that powder won’t conduct electricity to you.

Class D fires involve combustible metals.  Not all metals look metallic.  This designation comes from chemists.  Some metals are powders or amorphous lumps.  The problem with Class D fires lies in how the metal behaves with water.  Some metals explode on contact with water (sodium).  Some will burn even hotter when you apply water (magnesium).  In some cases, water will have no effect.  Factories using combustible metals are familiar with the characteristics of their product and have fire extinguishing agents on hand that address the specific idiosyncrasies of the product being machined.

Class K fires came up in the 1990s.  Fire experience and laboratory testing showed that use of vegetable oils with high auto-ignition temperatures was becoming more commonplace.  Standard Class B extinguishing systems were not keeping the fire suppressed for a long enough time, and the oils were re-igniting after initial extinguishment.  In 1998 the National Fire Protection Association changed the fire extinguisher standard creating Class K fire distinction.  Water, and many Class B extinguishing agents, won’t work on Class K fires.  Today commercial kitchens use special Class K fire extinguishers.

We spend a significant amount of time training on proper extinguishing agents and techniques.  At home, you need to know that water should not be used on stove-top cooking fires, flammable liquids in the garage, or on burning energized equipment.  The first step for ALL home fires is to call 911 and get us headed your way first (we really don’t mind!).  For cooking fires, cover the pot and shut off the burner.  For electrical fires, kill the power first, then fight the fire.  And for flammable liquids, use a dry chemical fire extinguisher.  If the fire is too big, remember to get the people out.  There are no things in your house that are more important than the people.

We hope you never have to fight a fire in your home.  But if you do, be sure you do it right.  If you’ve got questions, give me a call at 466-4602, or e-mail me at, or post your question here on this page.

What is Mechanical Cord Damage?

Electrical CordA good question came up a few weeks ago.  What constitutes ‘mechanical damage’ to an electrical cord?

Cord damage can be heat or mechanical.  Heat damage results from overloading (more amperage than the copper conductor can carry) or poor connections.  Poor connections can generate enough heat to melt things down.  A short circuit is a particular type of overload that can heat up just the area of the short or the entire cord.  If you heat a cord enough you can ignite nearby combustibles.

Mechanical damage comes from physical use or abuse and tends to fall into one of several categories.

Pulling cords out of sockets by the chord, rather than the plug, stresses the entire plug assembly.  You can pull the insulation out of the plug exposing wires (exposed wires means electrocution hazard).  Additionally that stress is translated to the wire connections in the plug and loosens connections.  Loose connections are a very common cause of electrical fires.  When pulling the plug from the socket, grab the plug, not the cord.

Pinching cords also causes problems.  Often cords get pinched in doors.  We attempt to preclude this with electrical codes requiring outlets in each room so occupants won’t have to run cords through doorways.  Some people route extension cords over driveways.  A car driving over that cord grinds the conductors together under around 4,000 pounds of weight.  In both cases, the cross sectional area (width) of the conductors gets reduced.  The amount of current a conductor can safely carry without overheating (and causing fire) is directly proportional to the cross-sectional area.  Decreasing that area by pinching, kinking or running over cords means that point will start to overheat.  Additionally, kinking cords can break down insulation and allow conductors to short circuit, which can lead to fire.

A third concern is grounding.  Most plastic appliance cases will protect you from electrocution in a short circuit scenario.  However, if the appliance case is metal, or if the amperage is high, the appliance may need a ground plug.  The ground plug provides a ready route for stray electricity (caused by a short circuit).  That helps protect users from electrocution if the appliance should short circuit.  Some consumers remove the ground plug.  Obviously that protection against electrocution is no longer in place.  It’s like a trapeze artist with no net.  It might not be a problem; or someday it might be.

Another common cause of mechanical damage comes from winding cords up on cord reels.  Vacuums, steam cleaners, and other mobile appliances typically provide a couple of plastic posts upon which the cord is to be wound when not in use.  The problem is that over time, the cord is wound the same way and bends (or kinks) at the same points.  Additionally it’s stored that way for the life of the cord.  These cords tend to fray and break down at those bend points.  If you change up the way you wrap your cord, or just coil the cord loosely and hang it from the top post, the cord will last much longer.  If you note the cord insulation wearing, breaking or fraying at these bend points, get the cord replaced.

Mechanical damage is probably the most common code violation we find on appliances.  A little attention to your appliance cords can ensure the appliance lasts longer and is safer to operate.

If you’ve got questions call us at 466-4602, or e-mail me at, or post your question here on this blog.

Clementine Orange Candle Test

Mandarin orange scented candleMy wife found something on Pinterest and told me I would want to know about it.

I’ve already had my wedding, I don’t need any new shoes, and I’ve settled on my own work-out routine.  There’s not much Pinterest has that I need.

However, my wife did find one that captured my interest.  Seems some ladies found a way to make an aromatic votive candle from a mandarin orange.  Now to a firefighter that translates as, “Cool, flaming oranges!”  Naturally we here at Fire Prevention Laboratories had to see if that works.

Clementines are a variety of mandarin orange that are usually grown in Mediterranean or Asian locales.  They’re often used as gifts or center pieces around the holidays.

In the Pinterest world you take a clementine mandarin orange and:

  1.  Make a cut in the peel all the way around the equator (leaving the poles intact).
  2. Then you peel the southern hemisphere off in one piece.
  3. Next you peel off the northern hemisphere carefully leaving some of the orange flesh attached to the center (belly button) of the northern hemispheric peel.
  4. Turn both peel halves upside down
  5. Eat the orange.
  6. You should have two orange peel cups.  Cut a star shape in the center of the southern hemisphere, that’s the lid.
  7. Now pour olive oil in the northern hemisphere just enough to make contact with the flesh in the center.  That flesh is to be the wick that pulls oil up and burns.

Sounds good, right?

We made seven samples using different cooking oils.  Thirty-four wooden kitchen matches later we got six to light.  Putting the decorative ‘lid’ on helped the tiny flame persist.  Of the six we got ignited only four persisted.  Of those four, only one made it across the parking lot to show the staff in the admin office.  We spent a lot of time re-igniting them.

Clementine 1-1

 Picture of our ignited clementine orange test candles taken with a GoPro Hero 2. This was taken after we performed the spill test.  Cooking oil (a combustible liquid) was the fuel here.  DO NOT try this with flammable liquids like lighter fluid.  That will result in a fire and probably injuries.



We performed the spill test.  After one had been burning for a while, we tipped it sideways on a paper plate.  Oil ran across the plate but nothing ignited.  The wick actually seemed to burn a little better with less oil in the orange peel.  But the flame remained a bit anemic.  The problem was keeping the flame lit, not spreading the fire.

Next we ran the ambiance test by closing the doors to witness the light effect.  It kind of looked like miniature jack-o-lanterns at Halloween.  It did, however, exude a rather sophisticated mood (for the inside of a fire department burn tower).


The ‘ambiance test’

Next we tested the aroma.  Never ask a firefighter if something smells nice.  They think barbecue smoke would make good perfume.  So we ran one of these by the staff in the admin office searching for an impartial panel of judges.  Now remember, these people smell a lot of smoky individuals coming through the front door.  Their assessment was that burning oranges stink.  There was no argument with that and they wanted the flaming orange votive candle out of their office space.  We considered that test concluded.

Bottom line is that you can fulfill the DIY gene by making your own mandarin orange votive candles and with persistence you might make it work.  However, centuries of have been spent researching candle materials that burn well, burn cleanly, do not smoke and smell nice.  We’re probably wise to take advantage of those years of technological advance.  Our recommendation is to get something from your local candle store that smells like an orange.  As with any open flame device, use great caution with your burning oranges (or any other burning members of the citrus family).  Got questions?  Call me at 466-4602, or e-mail me at, or post your comment here.

CAUTION – Hand Sanitizers Can Have Hazards

Hand SanitizerA recent news story  ( tells of a girl in a hospital who was burned when hand sanitizer ignited.  First off, our hearts go out to that girl and her family.  There is a kid who is fighting hard with a number of strikes against her and she still keeps on.  All kids have a soft spot in firefighters’ hearts, but kids like this are deserving of extra care and prayer.

Hand sanitizer became a staple in hospitals several years ago.  Studies reveal that hand-sanitizer helps reduce spread of disease in hospitals where patients are already compromised.  The practice works.

At that time most hand sanitizers were alcohol-based and that created some heartburn for fire marshals across the U.S.  Alcohol is readily ignitable and burns with a nearly invisible flame in daylight.

Most hospital patients are considered ‘non-ambulatory’.  They’re usually not able to get up and quickly move to safety on their own.  Fire codes provide special protection for non-ambulatory patients.  That level of protection is not helped by the presence of oxygen (which greatly increases fire behavior) and flammable anesthetic gases.  Fire codes address those added hazards and as a result hospitals are some of the most fire-safe buildings on the planet.  Now hospitals wanted to store alcohol-based gels in each room as well as in corridors we fire marshals were designing to be fire safe?  That sent everyone back to the drawing boards.

Recognizing the value of hand sanitizer for patient care, designers crafted safety features allowing hospitals to reap the benefits of hand sanitizers while preserving a level of fire safety that ensures everyone survives the fire hazards.  Dispenser size was regulated, locations were specified, leaks and drips were addressed and generally everyone felt pretty safe about hospitals and hand sanitizers.

Then they showed up in schools.  School nurses heard about the disease prevention success in hospitals and wanted that in schools.  Good idea!  They also showed up in retirement homes, colleges and grocery stores.  Now you can find a hand sanitizer dispenser just about anywhere.

We need to remember that the product is still flammable and has inherent hazards.  When used as designed, alcohol-based hand sanitizers should not be a problem.  In the case of the recent news story, the hand sanitizer was reported to have been used to clean a shirt.  That’s not what the designer intended hand sanitizer for.  The shirt caught fire, probably from an accidental static electric discharge.

Many occupancies use non-alcohol based hand sanitizer to avoid fire hazards.  Health care organizations indicate that may reduce the effectiveness of the disease prevention effort.

The moral of the story is that we must remain alert to the hazards present in all of the flammable and combustible liquids that we use every day.  Failure to do so can lead to disastrous results.   Stay alert to how you and your family use the flammable and combustible products in our daily lives.  That way the fire department won’t have to get involved.

Clean Dryer Vents Help Prevent Fire and Boost Dryer Performance

Dryer Lint TrapWe’ve touched on this topic in the past but today we’re going to explore clean dryer vents a little closer.

The Federal Emergency Management Agency (FEMA) reports that the leading cause of clothes dryer fires is operational deficiency including failure to clean the dryer and that lint is a close second to clothing as the first fuel ignited in dryer fires.  It seems that keeping lint cleaned up is a good idea.

First things first, clean the lint trap every time you use your dryer.  That trap is there for a reason.  It’s easily accessible and it’s simple to pull the lint out and put it in the garbage.

Secondly, clean your dryer vent system at least once a year.  In some cases it may be necessary to do this more than once a year.  If you have a large number of people using your dryer, or the vent tube is longer than 10 feet, or if your dryer is more than 10 years old, you may want to consider cleaning the vent tubing more often.

Third, we recommend that you use metal flex tubing rather than plastic.  Plastic melts at fairly low temperatures and melting plastic will feed the fire.  Metal tubing withstands higher temperatures than plastic, will help contain the fire and will not contribute to fire growth.

With those things out of the way, you can clean out your dryer vent system.

  1. Disconnect power to your dryer.  If you have a gas dryer, shut off the gas supply and disconnect the gas supply line in accordance with the manufacturer’s directions.
  2. Slide the dryer out from the wall.
  3. Disconnect the dryer vent tubing both at the wall and at the dryer.
  4. Using a shop vac or home vacuum, vacuum out the inside of the dryer where it connects to the vent tubing.  If your dryer is like mine, you’ll find a lot of debris here that made it past the lint trap.  USE CAUTION REACHING INSIDE!  Metal connections can have sharp edges and you don’t know what was once in someone’s pocket that is now lurking in a dryer vent to snag your hand.
  5. Now vacuum everything out of your vent tubing that you can get.  Collapse the tubing to get all of it vacuumed out.  Most texts indicate that you’ll find your biggest lint accumulations at either end of the vent tubing, but inspect the middle of the line also.  Take the tubing outside.  Shake it out so anything trapped inside can fall out.  If lint is stuck in the middle a plumbing snake can help get it out.
  6. Next, vacuum out the vent in the wall from the interior side.
  7. Now, go outside and remove the exterior dryer vent cover.  Sometimes you’ll need a screwdriver to accomplish this, but often the dryer vent cover is just snapped into the vent.  Vacuum this vent from the outside.  Once again, a plumbing snake can help remove clogs inside the line.
  8. Leave the vent cover off and re-connect the inside vent tubing to the dryer and wall connection.  Re-connect the power (and/or gas) to your dryer and run it for ten minutes with the exterior vent cover off.  This may blow some more lint out that you’ve loosened up.
  9. Vacuum any remaining lint and replace the exterior vent cover.

Cleaning dryer vents not only eliminates a fire hazard, it provides more efficient operation of your clothes dryer, faster drying times, and reduced operating costs.

You’re done.  Pop open a cold beverage and revel in the level of fire safety protection you have just afforded your family.  You identified and eliminated a problem.  You got up and did what needed to be done.  You ARE the man!  (or woman as the case may be)

Federal Emergency Management Agency. (2007).  Clothes dryer fires in residential buildings.  Retrieved February 13, 2013 from

WikiHow (n.d.).  How to clean a clothes dryer vent.  Retrieved February 13, 2013 from

Shop Woodstove Safety

Burnt car serviceWe lost a detached building the other day.  The structure was a shop/garage.  It was not a residence and no one was inside this structure so no lives were threatened.  The structure was a complete loss however.  While life safety was not impacted (and that’s good), we’re not quite willing to write the whole thing off as “no big deal”.

The owner used the building to work on cars.  The primary source of heat for the building was a woodstove.  The owner fired up the woodstove and went inside to eat something while the stove heated the shop up.  During lunch, the owner noted smoke and upon investigation found flames up the wall around the woodstove.  He called us and investigators found that the stove pipe ran from the stove up and then elbowed out through the wall.  The problem was that the installation only used single-wall stove pipe.

Spokane County requires that the minimum clearance between a single-wall stove pipe and an unprotected wall is 18”.  Anywhere the stove pipe penetrates a wall or ceiling, an approved installation must be in place to ensure the heated stove pipe doesn’t ignite combustible framing materials.  In contrast, most codes allow double-wall pipe to have a minimum clearance of 6” from combustible construction elements.

Many people take a relaxed approach to woodstove installations in shops and garages.  After all, no one sleeps in the garage so life safety isn’t much of a risk.  That may be true, but think about what you keep in your garage and ask if you can afford to lose it.  In most cases we have things stored that we’d just as soon keep around.  A bit of careful attention to woodstove installation can ensure the shop or garage doesn’t get burned down.

In our case last week, the only thing stored in the shop was a 1967 Camaro, and the tools the owner used to restore hot rods.  Give it some thought.  If your shop/garage woodstove installation is not up to code, you could be doing yourself a favor by ensuring it gets upgraded.

If you’ve got questions about woodstoves and fire places you can call us at 466-4602, or email me at, or you can post your questions here as comments on this blog.

Safety Tips for Frozen Pipes

Frozen PipesOne of our investigators spent an afternoon underneath a manufactured home yesterday.  Cold weather had frozen water pipes and the homeowner’s remedy resulted in a fire.  Cold weather is a fact of life here in eastern Washington.  Following are some tips to keep pipes thawed and your house intact:

1.    Prevention is the best medicine.  Insulate exposed pipes and protect them from cold.  Remember, anytime you enclose and insulate a space, wildlife will view that as a good place to hibernate or store food.  Squirrels and mice can rearrange your insulation so that your piping will be exposed again.  So check your piping every fall to ensure you won’t have a problem once winter hits.

2.    Pipe sleeves or UL-listed heat tape work well.  Once again, check these things every fall to ensure they’re in good working order.

3.    It may be prudent to hire a plumber to re-route pipes to locations where there is greater heat protection.

4.    If you’re in the middle of a cold snap and fear freezing pipes, turn faucets on just a trickle.  The tiniest amount of water movement will help.

5.    If water flow stops, it’s probably due to frozen water somewhere in the pipe.  As water freezes it expands.  That expansion in an enclosed pipe can split the pipe.  That will take a little time, so if you’ve just noticed a freeze-up and can locate the frozen spot, you have some options:

  • First things first.  Open the faucet so water, steam and heat from your thawing action can escape, rather than build up pressure and cause leaks.
  • Locate the frozen spot and start thawing on the side toward the faucet so that melted water can run out.  If you start in the middle or upstream of the frozen point, you’ll build up more pressure and perhaps cause a leak.
  • Wrap the suspect pipe with towels soaked in hot water.  Keep changing out towels, or pouring hot water on the towels until the frozen spot thaws.  Use a bucket underneath to catch drips.  This method localizes heat right where you need it and is probably the most efficient.
  • You can also use a hair dryer to heat up the frozen pipe.  This is not as efficient at using hot towels, but in tight spaces this may be your only option.
  • Wrap a heating pad around the suspected spot.  Do not leave the heating pad there indefinitely.  This is an emergency measure and the heating pad must be monitored constantly.  Remove the pad once the freeze-up is cleared.
  • Use space heaters only in accordance with manufacturer’s specifications.  Pay careful attention to distances around the heater and air flow.  Many heaters require some air flow to keep from overheating.  Remember that paper on fiberglass bat insulation will ignite.
  • NEVER use a torch.  Torches will melt plastic plumbing as well as soldered pipe joints.  Heat from a torch doesn’t just warm the pipe.  Torches also heat nearby wooden structural elements.  Even if the affected pipe is not near wood, metal plumbing will conduct the heat from a torch to combustible framing and start a fire.  Fires from using torches to melt frozen pipes are pretty common.
  • DO NOT use fuel burning appliances such as propane, charcoal barbecue, kerosene, etc. underneath or inside your house.  Fuel burning appliances produce carbon monoxide, the number one accidental poisoning killer in the United States.

No one wants to deal with frozen pipes this winter and we hope you don’t have this problem.  If you do, pay attention to the fire safety concerns outlined above.  We’d rather you not experience frozen pipes AND a fire.


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