Seasonal Safety Reminder: Be Aware of Mulch Fire Hazards

Seasonal Safety Reminder: Be Aware of Mulch Fire Hazards
Advice for Residents, Property Managers, Landscapers, and Nurseries

STOW—State Fire Marshal Peter J. Ostroskey today offered a fire safety reminder to homeowners and others who plan on using mulch in upcoming landscaping projects.

“Every spring, firefighters across Massachusetts respond to mulch fires on commercial and residential properties,” State Fire Marshal Ostroskey said. “These include fires that start with cigarettes and other smoking materials. Remember that mulch is combustible and can easily catch fire.”

The hazard is especially significant around residential structures because fires that start on the exterior of buildings are usually not detected early. By the time smoke and heat enter the building to trigger a fire or smoke alarm or sprinkler system, the fire is already large. Fortunately, many mulch fires are noticed and extinguished before spreading to a building or motor vehicle.

Provide Proper Smoking Receptacles

Smokers should never toss their cigarettes into mulch, dried leaves, or other debris, and mulch should not be placed in a designated smoking area. To help reduce this unsafe behavior, businesses and homeowners using mulch to spruce up their landscaping should also provide and maintain safe receptacles for disposing of smoking materials. Metal containers with sand are best.

 Keep Mulch at Least 18” Away from Buildings

Don’t place mulch directly against the side of a building. The Massachusetts Comprehensive Fire Safety Code (527 CMR 1.00, section 10.13.10.4.1) prohibits the new application of mulch within 18” around combustible exteriors of buildings, such as wood or vinyl but not brick or concrete. Residential buildings with six units or fewer are exempted from this regulation, but all homeowners may wish to adopt these safety practices voluntarily. The regulation applies to all other buildings, including commercial properties.

Keep Mulch Piles at Least 30’ Apart

The heat generated by large piles of mulch can cause them to ignite, so it is important to maintain a safe distance between piles. This can help prevent a fire in one pile from spreading to another pile or to a building. The Fire Code (527 CMR 1.00, sections 31.3.6.3.2.2 & 31.3.6.4.3) limits the size of mulch piles and requires distances of 30 feet between piles and 25 feet from the property line.

Permits Required to Store 300+ Cubic Yards of Mulch

Permits from the local fire department are required wherever more than 300 cubic yards of mulch are produced or stored.

 Call 9-1-1 to Report Smoldering Mulch Beds

Mulch can generate heat, and a smoldering pile of mulch can ignite. If you see a smoldering mulch bed, please call 9-1-1 so the fire department can make sure it is truly extinguished. Mulch can smolder for a long time before erupting into flames.

Educate Your Staff: Mulch Safety Pamphlet
DFS provides an educational pamphlet in English and Spanish on our Mulch Fire Safety page. It provides information that building managers, landscapers, and distributors can use to educate their staff. Local fire departments are encouraged to make it available as well.

Major Mulch Fires

Including preliminary data from 2021, there have been more than 400 fires in the past 10 years that started in mulch but spread to buildings. These fires caused five civilian injuries, 30 fire service injuries, two civilian deaths, and almost $15 million in damages.

Among these fires were a July 10, 2018, fire in Boston that caused an estimated $250,000 in damage to a six-unit apartment building and a May 5, 2015, fire in Arlington that claimed one person’s life destroyed 36 apartments and six vehicles. Both fires were caused by smoking materials that had been discarded into mulch beds.