Wood Mulch vs. Rubber Playground Surfaces

Wood mulch has been used on America's playgrounds and parks for decades. Thankfully, rather than concrete under those swings there is usually wood mulch. But is there a better option?

Wood mulch, commonly referred to as Engineered Wood Fiber, is a certified product that meets all applicable guidelines, with certifications from the ASTM, CPSC and IPEMA. Wood mulch is tested to be safe. Yet it's tested when it's brand new, leveled to the perfect depth, unfrozen, and untouched. It may be safe in the lab—but children play on playgrounds, not in laboratories. What happens when mulch gets wet and compacted? What happens when that fresh, moist, mulch dries out after being in the sun? It may no longer meet the safety standards.

Some of the mulch that is being marketed as playground surfacing is the same product used to mulch gardens. The wood fiber surfaces may come from recycled wood material. The problem is, wood pallets are made from treated wood which has proven to be toxic. It could contain nails and staples that got mixed into the shredded mulch. Still, wood mulch is one of the most widely-used 'safety' surfaces in the US.

The websites of the largest wood mulch manufacturers in the US are revealing. They have a long list of disclaimers.

Some direct quotes: According to Zeager.com, "During freezing conditions, all of our playground surfaces will naturally be less resilient, particularly with poor drainage. Restrict use of the area accordingly."

Fibar.com states: "Should there be moisture retention in the Fibar System, it will freeze when the temperature drops below the freezing mark. Please check your surface frequently in winter weather. When the surface is frozen, the impact attenuation properties of Fibar are lost and for this reason, the play area should not be used."

They suggest playgrounds be shut down for months on end? Children do not refrain from using the playground in cold weather.

One would think that in wood mulch would be safe in the heat of summer. But wood mulch was found to be hazardous in the dry summer season as well. The manufacturers state that "during a dry season, it may be necessary to wet the surface of the wood fiber with water in order to ensure sufficient moisture content to resist flammability."

Amerimulch.com explains that spontaneous combustion of mulch is not a mystery; it is the natural result of chemical reactions within organic materials. A CBS news article reported about a playground at a school in Arlington, Texas that spontaneously combusted due to smoldering wood mulch.

Luckily no children were playing on the playground. One could always choose to apply a fire retardant but then it's no longer a natural, chemical-free alternative.

Wood mulch is simply not appropriate for outdoor use—by the manufacturers' own admission.

Zeager.com, a leading wood mulch manufacturer's site, reveals that "Nuisance molds are not uncommon in wood fiber and wood mulch products. Despite the research that has already been conducted, a surefire solution to prevent visible fungus structures from forming has not been found yet. When the wood is wet, bacteria rapidly colonizes and the fungi feed on this bacteria which may lead to slime molds, mushrooms, etc. Short term solutions are to scoop out and dispose of the fungus."

A safer playground surface to consider is rubber. It comes in solid, poured rubber, loose fill, and rubber mulch type. It makes playgrounds soft and cushiony—as a playground should feel.

Rubber is the safest way to go, according to research by the EPA supports this assertion. Rubber surfaces have been proven, even in laboratory tests to have the highest shock absorbency level of any surfacing material.

Rubber surfaces don't freeze and harden. They don't retain dangerous heat levels in the summer. They are heavier than wood mulch, and resist displacement. They never degrade or decompose. They don't attract bacteria, and they don't retain slippery moisture. No disclaimers.

Most often rubber surfaces are made of 100% recycled rubber, saving hundreds of tons' worth of rubber from ending up in the landfills. The safest option for children is also the most environmentally responsible one. The Obama family chose a recycled rubber product for the playground at the White House—a fitting testimonial to the green era in which we live.

In years past, playgrounds were often set directly into the concrete. That caused hundreds of thousands of serious injuries. Today most playgrounds have some sort of safety surfacing. Still, over 500 kids end up in the emergency room every single day as a result of playground injuries.

We can do better. We have better options. It's time to move forward towards a safer play environment that rubber can provide.