Produce Safety: What Every Gardener Needs to Know
Has food ever made you sick? Each year, about 48 million people in the U.S. (1 in 6) get sick, 128,000 are hospitalized, and 3,000 die from foodborne diseases, according to recent data from the Centers for Disease Control and Prevention. These illnesses are a significant public health burden that is largely preventable. (1)
The Food Safety Modernization Act, passed in 2011, has given the Food and Drug Administration (FDA) new authorities to regulate the way foods are grown, harvested and processed to shift the focus from responding to foodborne illness to preventing it.
One of the critical components of the FSMA is the Produce Safety Rule (PSR). The PSR establishes, for the first time, science-based minimum standards for the safe growing, harvesting, packing, and holding of fruits and vegetables grown for human consumption. (2)
Training for Produce Safety
At the beginning of May, I attended the PSR Grower Training Course provided by the Produce Safety Alliance, a group of scientists and trainers from the University of Arizona and the Arizona Department of Agriculture. The course was beneficial and opened my eyes to many risks I hadn’t previously considered that could cause illness from our home-grown food. While the FSMA applies primarily to farmers/growers, a backyard gardener can glean some critical safety information to lessen the risk of illness from the food we grow. And if you occasionally sell your harvest, from your home or at a farmer’s market, then you should consider taking the PSR course and implementing a Food Safety Plan. The course is only $40 for a full 8-hours of training. Implementing a food safety plan will not only reduce risks of foodborne illness, the plan can also help reduce your liability. The course is very worthwhile and affordable.
According to Norman Barnett, AZDA Training Officer, “From backyard growers, hobby farmers or larger business, anyone interested in a safe food supply would benefit from attending the Grower Training Course provided by the Arizona Department of Agriculture and their partners at the University of Arizona Cooperative Extension.” Watch this link for upcoming training courses in your area: https://agriculture.az.gov/plantsproduce/food-safety-modernization-act
How We Get Ill from Food: Pathogens
The most significant risk in fresh produce is from pathogens, including bacteria, viruses, and parasites. Primary bacteria sources are E. coli, Salmonella, Campylobacter, and Listeria monocytogenes. Some bacteria (e.g., E. coli) can make people sick with a dose of 10 cells or less. Bacteria need the right conditions to grow: a food source, pH level, time, temperature, oxygen, and moisture. Most bacteria grow best between 40-140 degrees Fahrenheit. If you have ever completed a food handlers' course, you probably heard this referred to as the “danger zone.” Once fresh food has been allowed to rest in the danger zone between 2-4 hours, it should be used immediately. Longer than 4 hours, it should be thrown out. After you harvest your produce, eat or refrigerate as soon as possible. Listeria, however, is a bacterium that can multiply in the refrigerator and even survive freezing temperatures. (3)
Viruses may be spread by an ill person handling produce or by contaminated water. Only a few virus particles are needed to make someone ill, and they spread easily. Viruses can be very stable in the environment. (3)
Parasites that may contaminate food are Giardia, Toxoplasma gandii (often carried by cats), Cyclospora, and Cryptosporidium. They are also very stable in the environment but need a host to multiply. Some parasites can survive a long time in the body without producing symptoms. (3)
When vegetables and fruits are consumed raw, there is no cooking “kill step” to destroy pathogens. Therefore, the FDA often traces foodborne illnesses back to non-processed fresh produce. The rough surfaces of some produce (e.g., cantaloupes, lettuces, and berries) give pathogens a place to hide and cling, making it more difficult to wash them off.
How Pathogens Spread
Pathogens can be spread by 1) humans; 2) animals (livestock, pets, wild animals); 3) water; 4) soil amendments, and 5) surfaces, tools, and equipment.
Risk reduction includes identifying risks and making plans to mitigate them. The following are some examples of mitigating common risks:
- Wash your hands before picking produce or tending plants, and then wash the food thoroughly after harvesting. If the product will not be eaten within 4 hours, refrigerate as soon as possible.
- If you have known sources of possible bacteria (such as a chicken coop or other animal areas), avoid working in these places and then moving to the garden without first changing your clothes, shoes, and washing your hands.
- Take steps to limit animal and bird activity from your garden. For us backyard gardeners, our pets are one of the most significant risks. Cats are especially hard to keep out. On our farm we prevent animal entry by chain link fence around the row garden and bird netting over the top of it. In another area we use a shade house (wooden frame covered by shade cloth) that also prevents animal and bird entry.
- If you use a pitchfork, shovel, or rake to turn un-finished compost or clean up behind animals, don’t use the same tools on finished compost or in the garden area. It is less risky to have a separate set of tools to use specifically for your edible plants and trees.
- If you are using water other than tap water on your edible plants and trees, have the water tested.
- Do not eat any food that has dropped to the ground.
- Hot compost biological soil amendments with an aerated process and monitor the compost temperature to ensure temperatures over 131 degrees for a minimum of 15 days. Manure of any type has a very high risk of carrying pathogens.
- Some fruits and vegetables have parts that will contact the ground surface, including melons, squash, lettuces, and sprouts. These require extra care in cleaning. Avoid harvesting the portion of leaf lettuce or other greens that have been in contact with the soil surface.
Michael Brown, AZDA Training Officer, had this to say about the value of produce safety for everyone, “Making the best use of ensuring food safety is effective is to consistently apply the practices competently within the framework of each unique operational system and organizational culture, whether it be a one person backyard garden or a 100-plus person thousand-acre corporate farm. It’s pertinent for all to follow.”
1. Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Foodborne, Waterborne, and Environmental Diseases. (2011). Burden of Foodborne Illness: Findings. Retrieved from https://www.cdc.gov/foodborneburden/2011-foodborne-estimates.html
2. U.S. Food & Drug Administration. FSMA Final Rule on Produce Safety: Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption. (n.d.) Retrieved May 5, 2019 from https://www.fda.gov/food/food-safety-modernization-act-fsma/fsma-final-rule-produce-safety
3. Cornell University, Produce Safety Alliance. Produce Safety Alliance Grower Training. (2017)
4. United States Department of Agriculture, Economic Research Service. Salmonella and Toxoplasma gondii are the costliest U.S. foodborne pathogens. (2018). Retrieved from https://www.ers.usda.gov/data-products/chart-gallery/gallery/chart-detail/?chartId=88113