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Root Control Facts

This website and the Root Control Fact Sheet summarize restrictions and requirements governing the use of metam sodium* in sewers proposed by the US EPA in a decision published in 2009.


This website is provided by Sewer Sciences.  Sewer Sciences is not affiliated with the EPA.  The EPA does not endorse or recommend any products.


In its 2009 decision, the EPA concluded that metam sodium is likely to be carcinogenic in humans and can be disruptive to wastewater treatment plants.  Sewer Sciences believes that it is not safe to use metam sodium for chemical root control, and has stopped promoting it.  Instead, we promote diquat dibromide, which we believe is a more effective chemical than metam sodium.**  Moreover, diquat dibromide is regulated by EPA as a “general use” pesticide, while EPA regulates metam sodium as a “restricted use” pesticide.  Many municipalities no longer allow the use of carcinogens in their sewage collection system, now that better alternatives exist.


For a summary of new EPA regulations, click here.

For answers to frequently asked questions (FAQs), click here.

For links to US EPA documents and other primary source reports, click here.



*Not all chemical root control products contain metam sodium.

**Treats six times the length of pipe per equal chemical volume.