Rubber mulch
Photo credit: Dr. Linda Chalker-Scott Washington State University Extension
Q. Our HOA is considering using rubber mulch in a large area. In your experience, what is the up side or down side? I have read that as it deteriorates the chemical and all ingredients break down and go into the soil. Any thoughts? – LK, Lafayette, IN
A. This is a really great question that unfortunately does not yet have a clear answer. There are many questions remaining regarding the long-term safety of using recycled shredded or crumb rubber as mulch and playground surfaces. There’s little doubt that chemicals including heavy metals are released into the surrounding soil as the rubber decomposes. The question is whether those chemicals are at levels that would pose health risks. There are also issues with the rubber getting hot enough to burn tender plants. And there are many safer alternative mulches available.
Washington State University has published a fact sheet called “Rubber Mulch Use in Home Landscapes” that discusses its benefits and drawbacks.
The EPA has not regulated the use of rubber mulch at this time, so it has been left to local and state governments. The EPA reports that Connecticut, New York, New Jersey and New York City have published studies on the use of crumb rubber in artificial turf fields. While so far there has not been conclusive evidence of higher health risks from exposure in outdoor playing fields, these studies have not looked at the use of the rubber as mulch in the landscape or garden. And nearly all of the studies conclude that additional research is needed.
My advice is for the HOA members to read up on available information to be able to make as informed a decision as possible. If you do decide to use the rubber mulch for playgrounds, note that the Consumer Product Safety Commission has published guidelines found in the CPSC Public Playground Safety Handbook. https://www.cpsc.gov/s3fs-public/325.pdf
Here are additional articles to review:
http://gardenprofessors.com/rubber-mulch-rubs-me-the-wrong-way/
http://www2.epa.gov/chemical-research/tire-crumb-questions-and-answers
http://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/rubber-mulch.pdf