Keeping Floors Clean & Food Safe

The cleaning of floors in the food industry differs from site to site, and from process to process. Regardless, the goal is the same - to maximize hygiene and minimize food infection risks.

According to Hein A. Timmerman, water is one of the main culprits in a plant, particularly in a dry processing scenario. “It is known that water is a potential vector for spreading Listeria and creating the possibility of it being transferred onto product,” he notes. “For this reason, it’s important to keep the environment as dry as possible.”

He goes on to say that maintenance workers should avoid using hoses, but this is not always possible given how certain plants are laid out and how they function. “Break time cleaning should be carried out manually using buckets and cloths and sanitary wipes, rather than by pouring water over the production lines.”

In dry food processing environments, floor cleaning is usually carried out by brushing and vacuum cleaning. Periodically, wet cleaning is needed but should be done with great care to ensure all residual cleaning water is fully drained, and the floor is allowed to air dry.

“Often in facilities that produce high risk foods, there are no drains at all. In these cases, powerful disinfectants are used that can evaporate quickly and that have a specified non-rinse claim. An example is the alcohol-based Diversey™ Divodes FG VT29.”

Timmerman explains that in wet food processing areas, cleaning will be affected by the available cleaning equipment and how the process equipment is configured. “That’s because most of the time, floors are cleaned together with the external surfaces of the machines,” he says. “Foam is often used and is applied to all external surfaces. At the same time, adjacent floors are cleaned with the same chemistry.”

The chemistry he’s talking about is usually an alkaline foam with sequestrants or a chlorinated alkaline product. Periodically, workers apply formulations based on phosphoric acids. “The contact time lasts around 10 to 20 minutes, giving workers time to use brushes to scrub away stubborn soils. The foams are then rinsed with pressurized water at around 20 bar and with a flow rate of 30 – 35 l/m for each rinse hose.”

Drains, notes Timmerman, are not cleaned at intervals like the rest of the plant, but are cleaned continuously using available equipment and cleaning products. Disinfectants based on quaternary ammonium and amphoterics are particularly noteworthy, because they greatly help prevent Listeria.

Clean-in-place (CIP) is a method of cleaning equipment where dismantling and operator or manual involvement are kept to a minimum. It is typically used in the food and beverage industry, which requires frequent internal cleaning of equipment and processes to main high levels of hygiene.

Timmerman says such areas as the CIP room, place the greatest demand on resistant flooring. “That’s because a CIP installation uses strong chemistry as a basic material — products contain concentrated sodium hydroxide or potassium hydroxide up to 50%, nitric acid up to 62%, and the list goes on.” That list includes oxidative chemicals such as neat peracetic acid and sodium hypochlorite.

In CIP environments, temperatures can reach up to 80°C in storage vessels. “The risk of spills is high,” explains Timmerman, “but generally controlled cleaning floods are released over the flooring materials and then exit through available drains. In automated process areas, certain valves will have specific sequences to release high flows of diluted cleaning liquids onto the production floor during designated cleaning cycles.” He says other non-production areas are often cleaned with scrubber driers.

Though cleaning of floors may differ from one plant to the next, the one thing that remains common is the suitability and effectiveness of the cleaning chemistry. This even goes down to the level of dyes and odorizing elements — they’re not allowed.