MSU Extension Agrifood Safety

Produce safety managers put a lot of time, effort, and thought into training production workers on food safety policies, cleaning and sanitation SOPs, and health and hygiene best practices. Sometimes. it’s easy to forget that those workers who directly handle produce or work in sanitation aren’t the only ones who should receive annual food safety training and periodic refresher training. Farms and packing operations should start by reviewing health and hygiene policies with maintenance individuals but really emphasize microbial cross-contamination and biofilm harborage sites with this training.

Numerous research studies on biofilm-forming Listeria and salmonella on farms and in packhouse operations find that these pathogens often “work their way up” from non-food contact surfaces that act as harborage sites because these locations aren’t cleaned and sanitized as often as Zone 1 surfaces. Standing water on floors, floor drains, overhead door seals and tracks, cold room evaporator drip pans, leaky overhead pipes, dust-covered racks, fans and lighting fixtures, and processing equipment structural components or plumbing/wiring and even lift trucks are all examples of biofilm hazards that are more likely to be handled by maintenance and even third-party mechanical contractors than sanitation individuals.

As a food safety manager, it’s not as important to outline specific SOPs and Policies for how to deal with these surfaces, as much as having them understand the “why?” behind tool, equipment, and facility cross-contamination risk. It might be worth discussing sandwich/lamination joints, rough weld unions, areas behind flaps and hollow structures, as well as wheel bearings and hinges that can allow pathogens to hide from even the best sanitation individuals’ cleaning efforts.

Professional sanitation consultants recommend having a regularly scheduled opportunity for maintenance and sanitation individuals in leadership roles to walk through the farm or facility together and discuss worker traffic flow, product flow, hygienic zones, and how maintenance and cleaning schedules can align. Developing a pre-op checklist that sanitation, maintenance, and food safety individuals sign off on at the beginning of the shift is a way to take this one step further.

When non-food contact equipment items are brought back to the maintenance area, it's a great opportunity to have them cleaned with long-acting sanitizers like quaternary ammonium or iodine. Maintenance staff should be informed about what detergents and sanitizers are used for what equipment, with compatibility and structural integrity in mind for when equipment or materials are changed, including hardware bolts.

According to sanitation experts, the high microbial risk areas that maintenance needs to pay attention to so that sanitation efforts can be effective are: eroded conveyor belts and belt seams, exposed wall insulation, rusted or eroded floor drains, air ducts, air filters and vents, eroded flooring, space between walls, exposed wood surfaces in coolers and other high-moisture areas, inside pumps, open tube equipment supports, gaps between equipment, exposed gearboxes, motor shafts, and bearings, empty bolt holes, discontinuous welds, insect light traps, production worker tools, and tool storage areas.

For more information or something to show your maintenance team, check out this great YouTube video on hygienic facility maintenance presented by Eurofins US.