4 May 2021

Last month, a fire raged across land in Swansea, in southern Wales, spreading 6 hectares (about 15 acres) and injuring a firefighter. Weeks earlier, flames raged across 20 hectares (almost 50 acres) in nearby Fairwood Common, Gower, in a fire that may have been deliberately set, and another 30 hectares (74 acres) of grassland and forest burned in Maesteg, Bridgend. 

Almost 4,000 miles away in northwest Minnesota, crews battled a grass fire that briefly closed a highway in the area. Low humidity levels and strong winds created dangerous fire conditions across the state.

Effective prevention strategies

The vast majority of brush, grass and forest fires are caused by human activities, according to the National Fire Protection Association (NFPA). Leading causes include intentional fire setting, open burning of waste, smoking materials, and electrical power or utility lines. Grass fires take a toll on fire department resources, can spread to homes, vehicles and other property, and cause injuries, according to NFPA.

Grass fires can start and spread quickly and are extremely dangerous

Fire departments can use Information about the causes and circumstances of these fires to develop more effective prevention strategies and campaigns. When the conditions are right, grass fires can start and spread quickly and are extremely dangerous. They can travel up to 25 km (15 miles) per hour and pulse even faster over short distances. Grass provides a fuel that burns faster than bush or forests.

Creating fuel breaks

Grass fires may be less intense and produce fewer embers than bushfires, but they still can produce enormous amounts of heat. The taller the grass, the more intense the resulting fire; shorter grass height yields fires that are easier to control. Grass dries more quickly, so fires can start earlier in the day.

Living in an area with dried brown or golden-colored grass more than 10 cm (4 inches) tall is a fire risk. To manage the risk, homeowners should reduce the height and proximity of grass to their homes and other buildings by slashing, mowing, grazing, or spraying herbicide. Creating fuel breaks at least 3 meters (10 feet) wide can stop a fire and create a ‘defendable space’ around assets to be protected. Narrower fuel breaks may slow down fire spread but are unlikely to stop it.

Internal combustion engines

Use of machinery with internal combustion engines can increase the risk of grass fires

Use of machinery with internal combustion engines can increase the risk of grass fires. Tractors and other machinery should be free from faults or mechanical defects and equipped with an approved spark arrestor.

Small actions can help to avoid grass fires, such as disposing of cigarettes in a responsible manner, not leaving campfires and barbecues unattended, and clearing away bottles, glasses, and broken glass that can magnify the sun and start a fire.

Providing eye protection

Grass fires create a lot of radiant heat and can kill anyone caught in the open. The safest place to be during a grassfire is far away from the threat. In case of a grass fire, protective clothing should be available to cover up exposed skin, including a long-sleeved shirt and pants made from natural fiber.

A face mask or towel can be used to cover the mouth and nose. Smoke goggles provide eye protection. Other useful items are sturdy boots with woolen socks, tough leather gloves, and a wide-brimmed hat. A solid structure such as a building can provide shielding from radiant heat.