Rubber Mulch Safety

Scientists and gardeners have raised some concerns about rubber mulch, including the potential for environmental harm, health issues and termite infestations.

Description

• Rubber mulch is typically made of recycled rubber from car tires, dyed to match colors of natural or dyed wood mulch. Rubber mulch is used in gardens and on playgrounds, as a substitute for wood chip mulch.

Dyes

• There is no evidence presently available to draw conclusions about the safety of dyes used in rubber mulches.

Environmental Issues

• Scientists have raised concerns about high zinc levels and other contaminants from the recycled tires in rubber mulch. These contaminants can leach into soil and then into plants.

Health Issues

• One study done by the Environmental Protection Agency (EPA) found higher-than-background-level concentrations of particulate matter and metals at one playground site using rubber mulch, but other tests of volatile organic compounds and lead showed no increase over background levels. The EPA has recommended more comprehensive research be conducted.

Termites

• Experts disagree about the effect of mulching on subterranean termite populations. Some argue that all mulches, whether wood, organic, plastic, stone or rubber, should be kept back at least 6 inches from the edge of any home to avoid termite infestations and structural damage. Consult your local extension service for information about termites in your area.