Compost Fighting COVID-19

By Jessica Bowman and Frank Franciosi

As Americans around the country continue to grapple with the devastating economic and public health impacts of the COVID-19 crisis, many of us are taking a step back to consider our daily routines. In order to adapt to this new world, it’s important that we take this opportunity to evaluate these new risks against old practices. In recent years, as Americans have become more conscious of the waste they produce and their environmental footprint, many have turned to plant-based alternatives to traditional plastics, as well as begun to compost their organic waste. Here, the Plant Based Products Council (PBPC) and U.S. Composting Council (USCC) will examine the composting process in light of the COVID-19 epidemic.  

The process of composting involves many factors in the production of the final product: time, heat, temperature, moisture, carbon-nitrogen ratio, and others. Industrial compost facilities control these factors as both an art and a science in order to produce the highest-quality compost in the most efficient manner. In the process of turning organic waste into a soil-enriching product, all of these factors influence both the physical and chemical composition of the feedstock until it reaches its final stage as compost. With the current COVID-19 outbreak in consideration, consumers may have questions about the safety of handling compost when considering what to apply to gardens and landscapes as spring unfolds in the U.S. In short, USCC and PBPC want consumers to know that through the monitoring of composting process, producers follow all of the routine,  precautions, it is unlikely that COVID-19 is transferrable in commercial compost piles produced by following the procedures USEPA established for  a Process to Reduce Further Pathogens1 (PRFP).

Before describing what we do know, it’s important to be transparent about what we don’t know: this is a new stand of virus that has not been tested in a composting environment under the U.S. Environmental Protection Agency (EPA) 503 guidelines of the PRFP. However, what we do know is:

The COVID-19 virus is an enveloped virus with a fragile outer membrane. Generally enveloped viruses are less stable in the environment and are more susceptible to oxidants.  What does this mean? It means that with all the proper precautions that take place in the industrial compost process, (mixing into Aerated Static Pile, windrows or other processes), it is unlikely this virus is transferrable in commercial compost piles that have reached PFRP.

EPA regulations specify that significant reductions of pathogen populations during the composting process can be achieved by bringing compost to 55°C or 131°F for at least 3 consecutive days via aerated static pile method of composting or at 55°C or 131°F for at least 15 days with 5 turns, in a windrow method of composting. Meeting this benchmark for pathogen die-off is easily achieved by industrial composting facilities on a regular basis by industrial composters’ monitoring and controlling of compost pile temperature, moisture, and oxygen among other factors. All state permitted industrial composting facilities must meet this requirement as part of their operating permit and are required to provide documentation of this process.

With this in mind, consumer concerns should be eased regarding the safety of handling finished compost produced by these facilities during the COVID-19 outbreak.

For more information on COVID-19 as it relates to composting, please visit USCC COVID-19 Resources.

[1] United States Environmental Protection Agency. Biosolids Technology Fact Sheet: Use of Composting for Biosolids Management. September 2002. https://www.epa.gov/sites/production/files/2018-11/documents/use-composing-biosolids-management.pdf