Big storms from the Atlantic hit North Carolina so often that our NHL team is named the Hurricanes. When Hurricane Irene hit the eastern part of the state earlier this year a lot of folks with backyard gardens and commercial producers were asking questions about what types of contaminants might be floating around; what could be salvage; and, how to assess whether the land was safe to plant on in the future.

A couple of days following Irene we pumped out an infosheet for home gardeners with some recommendations gleaned from primary literature, other smart folks extension documents and FDA guidance for commercial crops. Yesterday, FDA released an updated, expanded set of guidance on what to do after a flood.

Some highlights of FDA’s Guidance for Industry: Evaluating the Safety of Flood-affected Food Crops for Human Consumption:
If the edible portion of a crop is exposed to flood waters, it is considered adulterated under section and should not enter human food channels. There is no practical method of reconditioning the edible portion of a crop that will provide a reasonable assurance of human food safety.

FDA’s guidance on direct contact is applicable to all food crops, including:
– Surface crops such as leafy greens, tomatoes, string beans, berries, and corn;
– Underground crops, such as peanuts, potatoes, carrots, and garlic;
– Crops with a hard outer skin or shell, such as watermelon and winter squash;
– Grains, nuts, corns, and similar products stored in bulk;
– Others (basically all food crops -ben).

For crops that were in or near flooded areas but where flood waters did NOT contact the edible portions of the crops, the growers should evaluate the safety of the crops for human consumption on a case-by-case basis for possible adulteration.

Assessment of flood waters

Knowledge of the sources of flood waters and any possible upstream contributors of human pathogens and/or chemical contaminants will help evaluate the likelihood of crop contamination by flood waters.

Type of crop and stage of growth

The likelihood of contamination may be low if: the edible portion of the crop has developed after the flood water receded; the lowest edible portion of the crop was above the floodwaters level with minimum risk of contamination due to splashing; and the crop can be harvested without cross-contamination from nearby environment, including flooded soil and flooded portion of the crop.

The likelihood for crops to absorb or internalize potential contaminants from flood waters and/or flooded soil

Although limited information is available regarding the likelihood and the extent for food crops to internalize potential contaminants from flood waters and/or flooded soil, research on plant uptake of contaminants from soil suggests that uptake is likely and the rate of uptake can vary depending on many factors, including contaminant type, plant species, and soil conditions

FDA recommends that, depending on the results of the assessment, that growers consider testing any one or more of the following contaminants, as needed, to determine the suitability for human food use. FDA recommends not replanting in flooded fields if flood waters have not receded and the soil has not sufficiently dried. 

Click here for the home garden-focused infosheet.