As the holiday season approaches, an increasing number of households will choose an artificial Christmas tree to decorate their home. According to data from the National Christmas Tree Association, nearly 14 million artificial trees were purchased in 2014, representing almost 35 percent of the total number of Christmas trees purchased and, with $1.2 billion in sales, more than half of the total retail market value of all Christmas trees sold in 2014.[i]

In general, consumers are aware of the potential fire hazard associated with the use of a natural Christmas tree. Every holiday season, numerous public service announcements and media stories remind consumers that Christmas trees not properly maintained pose an increased risk of fire, but frequent watering can greatly reduce this risk. However, consumers are often misled by artificial trees as packaging and/or advertisements typically identify the tree or tree materials as “flame retardant.” These claims suggest a certain level of fire performance and give many consumers a false sense of safety. In fact, research has demonstrated that some artificial trees can contribute to rapid fire growth in a room in a manner similar to that of a dried-out natural tree.

Currently, artificial trees sold with light strings (pre-lit trees) are evaluated for electrical, shock and other potential hazards in accordance with ANSI/UL 588, Standard for Safety for Seasonal Holiday and Decorative Products. UL has certified these products for a number of years, but the scope of the Standard was previously limited to pre-lit trees less than 30 inches in height primarily due to their potential contribution to a large scale flame event.

As the popularity of pre-lit Christmas trees has grown and the size of these trees has continued to increase, it became necessary to review and adjust safety requirements to address the increased fire fuel load of the materials used to manufacturer pre-lit trees. In response to this need, UL conducted research and developed fire performance testing requirements for pre-lit artificial trees exceeding 30 inches in height. The intent of the testing requirements is to understand a tree’s fire performance, thereby limiting its contribution to the growth of a fire and increasing escape time in the event of an incident. UL testing has shown that the peak heat release rate of freshly harvested natural Christmas trees, or those that are well-watered, is approximately 100 kilowatts (kW)[ii]. The objective is to have a pre-lit artificial tree that performs comparably with a freshly harvested natural tree.

A new white paper, “Reducing the Fire Hazard of Pre-Lit Artificial Christmas Trees,” was developed to provide a research-based risk assessment of these decorative items. This white paper reviews UL research which demonstrates that artificial trees, including pre-lit artificial trees, can be a significant contributor to rapid fire growth in a room. This research led to the publication of UL 2358, Outline of Investigation for Fire Tests of Pre-Lit Artificial Seasonal Use Trees and Other Seasonal Decorative Items, and testing requirements for this certification are outlined in the white paper.

The full white paper can be downloaded here. For more information about UL’s fire safety research and certification services for pre-lit artificial Christmas trees, please contact Anthony Tassone at



[i] “Consumer Survey Results,” National Christmas Tree Association, 2014. Web. 1 April 2014. Association, 2014. Web. 1 April 2016.

[ii] Data based on a freshly-harvested natural pine tree, and a well-watered natural fir tree after four weeks of indoor aging. From “Report of Research on Burning Characteristics of Natural and Artificial Christmas Trees in Room Fires,” Underwriters Laboratories, March 1, 1999