If dried out, a Fraser fir -- one of the most popular tree choices -- will burst into flames in less than 7 seconds if exposed to even the slightest spark. In less than a minute, the entire tree is an uncontrollable ball of fire.
However, if the tree is well-watered, any small flame it's exposed to will quickly die.
This is a lesson the National Institute of Standards and Technology (NIST) hopes to teach consumers this holiday season on why keeping a Christmas tree moist can be a matter of life-and-death importance.
Every holiday season, hundreds of homes catch fire when something as small as poor insulation on a Christmas tree light sparks or causes a small flame.
According to the National Fire Protection Association (NFPA), holiday trees fires cause 210 home fires, injure and kill dozens and cause more than $13.3 million in property damage every year.
The NFPA also reports that one in nine Christmas tree fires lead to a death.
To educate consumers, researchers at the NIST produced a side-by-side comparison video of two trees exposed to a small flame, resulting from faulty insulation on Christmas tree lights.
The needles on the tree on the left are fully moist; the moisture content of the other tree's needles is less than 10 percent.
As the video begins, the trees are ignited at the same time. Seconds in, the flame on the moist tree dies while the flame on the dry tree grows and spreads. At the 45 second mark, the dry tree is engulfed, giving off thick, black smoke.
By the end of the video, the well-watered tree is virtually unharmed, while the dry tree is a charred remnant.
The video has been shown on local and national television during the holiday season since its debut two years ago.
"Every year it is picked up by many local television stations to remind people of the risks of fire during the holidays, says Fire Fighting Technology Group Leader Dan Madrzykowski.
The NIST "Fire Safety for the Holidays" website shows videos of earlier NIST experiments that tell similar stories.
"Dry Scotch Pine Tree Fire" shows the damage a dry tree exposed to an open flame can cause in a lighted room full of furniture. All is ablaze until the room is in total darkness within 46 seconds.
Another of the NIST's videos shows the striking difference a residential sprinkler system can make.
The burning tree sets off the single room sprinkler in about 10 seconds and puts the tree fire out within three and one-half minutes. The sprinkler system keeps the fire from spreading to nearby furniture, which would cause it to flashover and quickly spread throughout the house.
In order to keep live Christmas trees fully watered, you can do what the NIST did for their experiment. They had an additional two inches cut from the trunk's bottom and placed the tree in a stand that could hold at least two gallons of water.
Check the stand every day to ensure the tree has enough water. Check the tree's needles, too.
Moist trees keep their bright green color and are pliable while the needles on dry trees break and easily fall off when shaken.
