Manure and Compost


NOTE: This text has been updated to reflect changes in the proposed FSMA rules as of October 2014.


Background

Farmers use soil amendments such as manure and compost to improve soil fertility and soil quality, and to enhance populations of beneficial microorganisms in the soil.  Sustainable and organic producers in particular rely on manure and compost instead of synthetic chemicals to add fertility to their fields.

The Food Safety Modernization Act (FSMA) requires the Food and Drug Administration (FDA) to develop regulations aimed at improving the safety of produce.  Soil amendments such as manure have been identified as a potential vector for pathogens that may contaminate produce, and Congress required FDA to include standards for “soil amendments” when developing new regulations.  In the proposed Produce Rule, FDA has developed standards directed to “biological soil amendments of animal origin” – e.g., manure and compost that includes animal waste and human waste.

In addition to requiring standards on soil amendments, Congress also specified that FDA could not propose requirements that conflict with or duplicate the requirements for certified organic production.  Manure and compost are critical soil amendments in certified organic production and in sustainable farming systems, and it is important that new standards work for these types of systems.  Congress also required FDA to take into consideration conservation and environmental practice standards such as those by USDA’s Natural Resources Conservation Service, which offers assistance with nutrient management and composting facilities, among other conservation practices.

Proposed Standards Directed to Manure and Compost

The proposed standards for biological soil amendments of animal origin and human waste include:

  • Definitions for determining whether the soil amendment is treated or untreated;
  • Microbial standards applied to treatment processes;
  • Application requirements and minimum interval requirements;
  • The option to offer an alternative approach;
  • Instructions for how to convey, handle, and store soil amendments;
  • Prohibitions on the use of human waste; and
  • Recordkeeping requirements.

The requirements only apply to biological soil amendments of animal origin – including manure, bloodmeal, and fish emulsion – and human waste.  They also address agricultural tea (“compost tea”).  They do no apply to non-biological soil amendments (e.g., physical or chemical) and they do not apply to soil amendments of non-animal origin such as yard waste, purely vegetative matter, or shrub trimmings.

Broadly, the proposed standards seek to avoid contamination of “covered” produce (click here for the list of produce subject to the requirements of the Produce Rule) by pathogens potentially present in biological soil amendments of animal origin.  Generally, the proposed standards set treatment requirements for soil amendments and minimum intervals between application and harvest.

However, as explained in more detail below, in the revised version of the proposed Produce Rule, FDA has significantly modified its approach to the minimum interval requirements for raw and composted manure. 

What the Proposed – and Re-Proposed – Standards Require

The interval between application of a biological soil amendment of animal origin and harvest of covered produce is dependent on whether that amendment has been treated and, if yes, how it was treated.

Treated Amendments

The following intervals between application and harvest apply, depending on the type of treatment that the biological soil amendment of animal origin has undergone:

  1. No interval if the amendment has undergone a scientifically valid controlled physical process, chemical process, or combination of physical and chemical processes that satisfies the microbial standard for Listeria monocytogenes, Salmonella species, and E. coli O157:H
  2. No interval if the amendment has been applied in a manner that minimizes the potential for contact with covered produce during and after application, and if the amendment has undergone a scientifically valid controlled physical process, chemical process, or combination of physical and chemical processes that satisfies the microbial standard for Salmonella and fecal coliforms
  3. No interval if the amendment has been applied in a manner that does not contact covered produce during and after application, and if the amendment has undergone a scientifically valid controlled composting process that satisfies the microbial standard for Salmonella and fecal coliforms
  4. No interval** if the amendment has been applied in a manner that minimizes the potential for contact with covered produce during or after application, and if the amendment has undergone a scientifically valid controlled composting process that satisfies the microbial standard for Salmonella and fecal coliforms

**This is a significant change from the original rule.  FDA originally proposed a 45-day interval for compost, which conflicted with the National Organic Program (NOP).  NOP regulations do not require an interval between application and harvest for manure treated by a composting process that is consistent with NOP composting standards.

For composted manure, FDA approves two scientifically valid controlled composting processes:

  1. Static composting that maintains aerobic (i.e. oxygenated) conditions at a minimum of 131 degrees Fahrenheit (55 degrees Celsius) for 3 days, and is followed by adequate curing, which includes proper insulation.
  2. Turned composting that maintains aerobic conditions at a minimum of 131 degrees F for 15 days, with a minimum of five turnings, and is followed by adequate curing, which includes proper insulation.

FDA will also accept “alternative” methods if they are scientifically valid, controlled composting processes supported by adequate scientific information or data.

In the case of agricultural tea, the water used must meet the requirements of the water standards.

Untreated Amendments

FDA considers a soil amendment to be untreated if it has not been processed by the treatments described above, has been contaminated after treatment, has been recombined with an untreated amendment, or is contaminated with a hazard.  FDA considers agricultural tea to be untreated if it contains an agricultural tea additive.  If there is no chance that covered produce will come into contact with the soil amendment during and after application, then there is no interval.

FDA had originally proposed to require a nine-month interval between application and harvest if the soil amendment is untreated and there is chance that the amendment will come into contact with covered produce after application.  In the re-proposed rule, FDA has significantly modified this approach.

First, FDA is proposing to defer its decision on the 9-month interval. FDA acknowledges the limitations of available scientific studies, the lack of scientific evidence to support a 9-month interval, and the great need for more research to be done before FDA can establish a science-based application interval.  Therefore, FDA is proposing to conduct a risk assessment on the safe use of raw manure in covered produce fields, considering a range of variables (e.g. type of manure, method of application, climatic conditions, type of commodity, and soil characteristics).  FDA is also committing to working with USDA and other stakeholders to conduct research on appropriate application intervals to ensure the safety of covered produce when raw manure is applied to a field and covered produce is reasonably likely to contact the soil.  The research will address a range of issues, including (and in particular), whether an how application intervals can be tailored for specific commodities, types of commodities, growing environment, and any other agro-ecological conditions.  FDA encourages the farming community and others to join them in this effort.

Once the risk assessment is conducted, FDA will use that information to propose a new application interval.  The public will have the opportunity to comment on the new proposed interval before it is finalized.  This process could take anywhere between 5-10 years, during which time the Produce Rule will not require farmers to follow any particular application interval.  However, FDA states that following NOP regulations is a prudent choice until FDA proposes and finalizes an interval.

Second, and in the meantime, FDA will work with USDA and other stakeholders to encourage the transition of the produce grower community to use composted rather than raw manure.  FDA is seeking input on what barriers to compost currently exist, and what resources are necessary to improve the infrastructure for making and accessing compost.

Additional Requirements

FDA requires farmers to handle, convey, and store biological soil amendments of animal origin in a way that does not contaminate covered produce; food-contact surfaces; areas used for growing, harvesting, holding, and packing; and water sources and distribution systems.  Farmers must also make sure that treated amendments are not contaminated by untreated or “in-process” amendments.

FDA does not allow the use of human waste for growing covered produce, except for sewage sludge biosolids that are used according to Environmental Protection Agency requirements.

To accompany these proposed standards, FDA lays out specific recordkeeping requirements.  These include documentation of the application date of any untreated or composted biological soil amendment of animal origin (except when there is no chance that the covered produce will come into contact with the soil after application).  For soil amendments treated by a third party, documentation is required that details certain requirements.  For soil amendments that a farmer treats, documentation showing process controls is required.  If a farmer is using alternative methods, documentation in the form of scientific data or information is required.

What the Proposed Standards Do Not Require

The proposed standards for biological soil amendments of animal origin do not apply to soil amendments of purely non-animal origin.  Additionally, the requirements do not apply to physical or chemical soil amendments, such as synthetic fertilizers.

The preamble also clarifies that the microbial standards are not meant to be lot-by-lot testing requirements, and testing is not required to validate treatment processes.

These standards do not apply to animal feces deposited in a field by wild or domesticated animals.  Separate standards apply in that instance.

FDA Needs to Hear from YOU About Manure and Compost:

If you use soil amendments such as manure or compost that uses animal waste, FDA needs to hear from you about how these proposed rules might impact your farm operation.

Here are some questions to guide your comments on this part of the proposed Produce Rule:

  • Do you use biological soil amendments of animal origin in your farming system?  If yes, what kind?
  • Do you use raw manure on fields where you grow produce?  If yes, when do you typically apply the manure?
  • Will these requirements discourage you from using manure or compost that includes animal waste?
  • Do you make compost on your farm?  If yes, what type of treatment processes do you use?
  • Are the composting treatment processes required by FDA reasonable or not?
  • Do you buy compost from a third party?  If yes, are the documentation requirements reasonable?
  • What do you see as barriers to your use of compost?
  • How will these requirements change your farming practices, if at all?
  • If you think FDA made the right decision to wait on finalizing an application interval for raw manure until it does more research and a risk assessment, be sure to say so in your comments!
  • If you think FDA made the right decision to eliminate the 45-day interval for compost, be sure to say so in your comments!

In addition to comments on the proposed standards, the specific issues that FDA would like comment on in this part of the re-proposed regulations include:

  • Comments on their new approach to defer finalizing the application interval under they conduct more research and a full risk assessment to justify a new proposed standard.
  • Data (published or unpublished) or scientific studies on the persistence of human pathogens in raw manure in an open environment under various agro-ecological conditions.
  • Information on nitrogen availability and the costs associated with various fertilizer options available to produce farms.
  • Information on the methods of use and prevalence of use of raw mnaure, including practices by small farms.
  • Information on current barriers to using compost.

How do I submit a comment to FDA?

Our step-by-step instructions show you how.

Additional Resources

Thanks to NSAC member organization Wild Farm Alliance for their assistance in developing this analysis!

This information may be shared if credited to NSAC and accompanied by a link to this page.