The U.S. Food and Drug Administration released a report on its inspection and environmental sampling of ice cream production facilities for Listeria monocytogenes and Salmonella in 2016 and 2017. The results underscore the need for commercial ice cream makers to ensure that they are implementing effective strategies to keep harmful bacteria out of their facilities.

Inspecting food facilities and collecting and testing samples from the environment where foods are produced are two of the many ways the FDA works to better understand microbial hazards and to help prevent contaminated products from reaching consumers.

The agency began the assignment on August 1, 2016, following 16 recalls of ice cream products due to the presence of pathogens in the prior three years, and an outbreak of listeriosis linked to an ice cream maker in 2015.

The FDA conducted inspections and environmental sampling of 89 ice cream production facilities in 32 states from September 12, 2016, to August 30, 2017. In selecting facilities for inclusion in the assignment, the agency sought to ensure representation from throughout the country and focused primarily on larger establishments whose product would be expected to reach greater numbers of consumers.

The FDA collected two environmental samples at each location. The samples tested for Listeria monocytogenes consisted of at least 50 subsamples each, and the samples tested for Salmonella consisted of at least 100 subsamples each. The assignment did not include the testing of finished product.


Key findings of this assignment include:

  • The FDA detected Listeria monocytogenes in 19 of the 89 establishments (an establishment-based prevalence of 21.3%), and in 65 of the 5,295 subsamples (a subsample-based prevalence of 1.25%). The detected Listeria monocytogenes was found on non-food contact surfaces in 18 of the 19 establishments, and on food contact surfaces in the one other establishment where the pathogen was found.
  • The FDA detected Salmonella in one of the 89 ice cream production facilities (an establishment-based prevalence of 1.1%), and in one of the 7,004 subsamples (a subsample-based prevalence of 0.01%). The detected Salmonella was not detected on a food contact surface.
  • With respect to the assignment inspectional outcomes, the FDA classified 44 of the 89 inspections (49.4%) as “No Action Indicated (NAI),” meaning no objectionable conditions or practices were observed during the inspection; 39 inspections (43.8%) as “Voluntary Action Indicated (VAI),” meaning objectionable conditions or practices were observed and documented, but the operation should be able to address them without official action by the FDA; and six inspections (6.7%) as “Official Action Indicated (OAI),” meaning objectionable conditions or practices warranting official action by the FDA were observed and documented.

As a result of the assignment findings and with support from federal and state health officials, the FDA suspended Working Cow Homemade Inc.’s food facility registration. The firm subsequently ceased operations. The FDA lifted the suspension four months later after the firm changed its business model to exclude production and focus on storage and distribution of ice cream made by other manufacturers. The agency also worked with two firms to conduct voluntary recalls (one being the firm that had its registration suspended), held seven regulatory meetings, and notified management at 39 facilities of the need to take corrective actions. In addition, follow-up inspections are being conducted by the FDA at all the facilities that received an OAI classification.

Although this assignment was not conducted to ensure compliance with the Preventive Controls for Human Food rule established by the FDA Food Safety Modernization Act (FSMA), the findings affirm that Listeria monocytogenes and Salmonella may be present in ice cream production facilities. The FDA began the assignment about one month before larger food facilities were required to comply with the rule, and one to two years before small and very small businesses were required to comply. The findings underscore the need for commercial ice cream makers to ensure that they are controlling hazards in accordance with the rule.

For additional information on the FDA’s sampling work and to read the report on its inspection and environmental sampling of ice cream production facilities, visit the agency’s Environmental Sampling page.