The U.S. Food and Drug Administration (FDA) has announced the first opportunity for the public to weigh in on their approach to assessing the risks posed by raw manure used in growing produce.

According to the FDA:

The risk assessment will consider pathogen survival and growth under different agricultural and ecological conditions (e.g., soil types, application methods, geographic locations, climatic factors) and under different time intervals between when manure is applied and the crop harvested.

The risk assessment will take into account available data and information on relevant steps in the produce food safety continuum including:

• The initial prevalence and levels of pathogens in untreated manure;
• The methods used to apply untreated manure to soils;
• Pathogen survival (and growth) in untreated manure and soils amended with untreated manure;
• Pathogen transfer to produce grown in amended soils; and
• Pathogen survival and growth on produce, including cross-contamination during storage and other steps in the supply chain (g., washing).

FDA is seeking information and data from farmers and researchers to help develop this risk assessment.

What does FDA want to know?

FDA is interested in a wide range of information and data about on-farm practices related to the use of untreated manure. This includes information on the:

• Extent to which untreated manure is used in different regions in the United States;
• Types of untreated manure, soil type, and crops typically grown in each manure-amended soil type;
• Proportion of produce farms that have one or more soil types per geographical location;
• Amount of untreated manure applied per unit surface (e.g., per acre) or the ratio of untreated manure/soil;
• Time of year, number of applications, and amount of untreated manure typically applied;
• Method of application (e.g., surface, incorporated), and whether or not the amended soil is covered (e.g., with plastic mulch);
• Climate conditions and other agronomic factors (i.e. irrigation or other practices) after soil is amended;
• Crop density, furrow width, and the influence of such factors on pathogen transfer;
• Harvesting practices and average climatic conditions (and range of conditions) prior to harvesting (e.g., time and temperature, rain events);
• Harvesting, handling, and storage conditions that may affect pathogen detection, survival, growth, or inactivation between harvest and retail sale;
• Typical storage conditions (e.g., time, temperature) for produce (in general and/or commodity-specific) from harvest until consumer purchase and whether and how those storage conditions affect pathogen levels;
• Types and concentration of antimicrobial chemicals or other treatments, if any, applied to the water used for wash or transport of produce during farm or other distribution operations prior to retail, and the efficacy of these treatments in reducing pathogen levels, as well as the likelihood of cross-contamination during wash or transport; and
• Storage conditions, such as times and temperatures, that may affect pathogen growth and/or survival during transportation and storage of produce in the consumer’s home, and consumer handling practices with respect to produce after purchase, including data and information on consumer washing practices.

See the full list via FDA’s announcement.

Why does FDA want this information?

This call for comments comes as part of FDA’s new food safety rule governing produce farms, in which FDA deferred finalizing a standard requiring a specific time interval between when raw manure could be applied to produce fields prior to harvesting. As you may recall, FDA had originally proposed to require that produce farms covered by the rule wait nine months between applying raw manure and harvesting. This application interval was longer than some growing seasons, which would have resulted in mandatory fallowing of fields, and could have severely disrupted sustainable and organic production practices.

In response to these concerns, FDA revised its approach in the second draft or “supplemental” Produce Rule. In the supplemental proposed rule, FDA acknowledged the limited body of currently available scientific evidence relating to the proposed 9-month interval and the need for additional research in this area, and described its planned risk assessment and research agenda.

In the final rule, FDA followed through with the proposal from the second draft and deferred finalizing the application interval for raw manure when applied in a manner that does not contact produce during application, but there is some potential that contact could occur after application.

In general, there are no timing restrictions on manure that is applied in a manner that will not contact covered produce. There also are no timing restrictions when properly composted manure is applied in a manner that minimizes the potential for contact with covered produce during or after application. See our blog analyzing the Produce Rule standards for more on what’s required.

It should be noted that we have been referring only to raw and composted animal manure; however, these requirements apply to all “biological soil amendments of animal origin.” While animal manure is the most common of these, biological soil amendments of animal origin also include other non-manure amendments, like bone and fish meal.

So what happens next?

FDA’s plan for finalizing the appropriate application interval(s) for raw manure involves supporting the necessary research and undertaking a robust risk assessment. The results of the research will feed into the risk assessment, which will ultimately inform a new proposal. FDA has indicated that it will take 5-10 years before they have the necessary data and information to put forward a standard that is appropriately science- and risk-based. Such a standard will have to undergo a public comment process just as these rules did.

In the meantime, FDA notes:

We have placed restrictions on how raw manure is applied. The final Produce Safety rule requires that covered farms not apply raw manure in a manner that contacts produce covered by the rule during application. And these farms are required to minimize the potential for contact after application.

To minimize the chance of contamination, we also stated that we believe it would be prudent for farmers to comply with the USDA’s National Organic Program standards related to raw manure use while the research and risk assessment is ongoing. These call for a 120-day interval between the application of raw manure for crops in contact with the soil and 90 days for crops not in contact with the soil.

This call for information provides the public – including farmers and researchers – with an opportunity to assist FDA in developing a robust risk assessment, and to help guide additional research to be done on this topic.

There will be additional opportunities for public comment on this issue, including a public meeting, as well as commenting on the draft risk assessment itself.

Comments are due by May 3^rd, and can be submitted via the Federal Register.