With the holiday season fast approaching, the presence of combustible decorations, festive lights, and Christmas trees has also arrived. The presence of additional furnishings and contents, especially dry and unmaintained Christmas trees and other vegetation can contribute significantly to the fuel load of a space and how quickly a fire can develop and spread.
During this time, those responsible for enforcing fire and life safety codes face the challenge of ensuring businesses and residences are following the provisions for furnishings and decorations, as many consumers are unaware of the potential fire safety hazards they could be installing in their facilities and in their homes. Here we will discuss the requirements for combustible vegetation and both natural and artificial Christmas trees.
Hazards of combustible vegetation and natural cut trees
Combustible vegetation can include a variety of items, such as hay bales, limbs, leaves, and Christmas trees. These items, by their nature, are initially fire retardant. The problem arises when they have been cut and packaged, often early in the season, without access to water for extended periods of time. The fire danger of Christmas trees and similar vegetation increases when the tree is not freshly cut and immediately placed in water when purchased. And, the longer they are on display, the increase in potential for the tree to go unwatered and unmaintained.
The best preventive measures for avoiding a dried out tree include using a freshly harvested tree, cutting the butt or bottom end immediately before placing it in water, and checking the water level frequently to ensure that the tree water container is filled. To check the tree itself for dryness, it is best to check a branch near the trunk and allow it to slide between the thumb and forefinger. When needles shed easily, the tree should be removed or replaced, since trees dry from the inside out.
In 2016, students at Worcester Polytechnic Institute constructed a mock living room setup at the fire protection engineering lab at to demonstrate how rapid and intense a dry tree can burn, complete with furniture, rug, curtains, and a decorated Christmas tree. The dry tree was exposed to a flame and within 25 seconds, the branches were fully engulfed and within another 10 seconds, fire had spread to the ceiling and to nearby furnishings. The entire room was thick with fire and smoke, and flashover occurred within 63 seconds.
The Fire Research Division at NIST conducted a series of fire experiments to demonstrate how a watered Christmas tree may be less of a fire hazard than a dry one. The Christmas tree that was maintained in a stand that was kept filled with water prior to testing did not ignite when exposed to the same ignition source as the Christmas tree that was not watered. A slower growing fire can mean more time to react, escape, and notify the fire department and can also reduce the damage done by the fire.
Where are natural Christmas trees permitted?
Natural Christmas trees are prohibited or limited in their placement in occupancies that pose special challenges due to the capabilities of occupants, occupant or management control, or the number of occupants. Some exceptions permit live, balled trees, if maintained, and trees in locations where automatic sprinkler systems are installed. Because a living tree needs moisture to stay alive, a balled, living tree should be placed in a container so that the root structure of the tree can be kept moist. (Note: artificial vegetation, including artificial Christmas trees are not limited in their location). Limitations for where natural Christmas trees can be located is as follows:
Limited quantities of other combustible vegetation is permitted in any occupancy if the AHJ determines that adequate safeguards are in place. Adequate safeguards might include sprinkler protection, limited quantities, moisture content, and placement. It is not the intent to consider a Christmas tree “limited quantity of combustible vegetation” where the display of Christmas trees is otherwise prohibited. For example, no natural Christmas tree, cut or balled, is permitted in assembly occupancies. It is not the intent to allow the presence of natural trees if enforced as being a “limited quantity of combustible vegetation”. The requirement for Christmas trees is more restrictive and should prevail.
Other considerations for natural cut trees
No means of egress is permitted to be obstructed by any combustible vegetation item or Christmas tree. The preferred location for a Christmas tree from a property owner’s perspective is often in the lobby, the reception area, or a similar area. However, trees located in these areas often encroach on the means of egress and present an increased danger should a fire occur.
When determining where to place combustible vegetation items or Christmas trees, an important consideration is that they might fall over, especially if children or pets come in contact with the tree or vegetation. Placing a portable heater, other heat source, or heating vent near combustible vegetation is prohibited, because the vegetation might tip and also because the heater will likely prematurely dry the vegetation, increasing the risk of a fire.
To maximize the moisture retention of the tree, the bottom end of the trunk should be cut off with a straight cut at least 1⁄2 in. (13 mm) above the end prior to placing the tree in a stand to allow the tree to absorb water. The tree must then be placed in a suitable stand with water and the water level must be maintained above the fresh cut and checked at least once daily. When the tree shows evidence of drying it must be removed from the building immediately.
On the market today are treatments for natural cut Christmas trees that claim to improve the fire performance of the tree. However, the use of untested fire retardant treatments may actually increase the rate at which the tree dries out and can contribute to the rapid growth of a fire.
Where fire retardant treatments are applied to natural cut Christmas trees (the treatments are not required), the fire-retardant treatment (not the tree) is required to comply with both Test Method 1 and Test Method 2 of ASTM E3082, Standard Test Methods for Determining the Effectiveness of Fire Retardant Treatments for Natural Christmas Trees. This standard provides a two-step testing process for determining the effectiveness of surface applied treatments for natural Christmas trees to improve fire test response. In order for a treatment to be considered compliant with ASTM E3082, the passing criteria of both Methods 1 and 2 as prescribed in the standard are to be met.
Artificial vegetation including Christmas trees
There are no limitations on what occupancies permit the use of artificial Christmas trees so it’s important that their potential contribution to fire development and flammability be controlled. Combustible artificial decorative vegetation and artificial Christmas trees must now meet the appropriate fire test criteria. This includes requirements for compliance with either the flame propagation performance criteria of Test Method 1 or Test Method 2, as appropriate, of NFPA 701 or a maximum heat release rate of 100 kW when tested to NFPA 289, using the 20 kW ignition source. NFPA 701, Standard Methods of Fire Tests for Flame Propagation of Textiles and Films, establishes test methods to assess the propagation of flame of various textiles and films under specified fire test conditions. NFPA 289, Standard Method of Fire Test for Individual Fuel Packages, describes a fire test method for determining the fire test response characteristics of individual fuel packages in a room when exposed to various ignition sources in a controlled environment. Each individual artificial decorative vegetation item (Christmas tree) must be labeled, in an approved manner, to demonstrate compliance with one of the fire test options noted above.
Additional requirements for Christmas trees
Another hazard associated with Christmas trees is the decorative lighting. Electrical wiring and listed luminaires and lighting used on combustible artificial or natural Christmas trees must be listed for that particular application. The listing will also dictate whether the lights have been tested for indoor and/or outdoor use. In addition to the listing requirement, lighting should also be checked for wear and tear and damages. Worn or damaged wiring and loose bulbs may present unsafe conditions. Electrical lights shall be prohibited on metal artificial trees. Candles and open flames cannot be not be used on or near combustible artificial or natural decorative vegetation and Christmas trees.
Looking for more information?
Requirements for artificial and natural Christmas trees and other vegetation can be found in both NFPA 1, Fire Code, Chapter 12 as well as NFPA 101, Life Safety Code, Chapter 10. The 2021 editions of both Codes were updates to include the specific fire test requirements as well as other clarifications for how to safely include Christmas trees in your business or residence.
NFPA also offers many additional resources on holiday safety, including a Christmas Tree Safety Tip Sheet and information on Christmas tree and decoration fires. All holiday safety information can be found here.