By Steven Sklare
September 23, 2019
Anyone in the foodservice industry knows slime when they see it, whether it’s inside the ice machine, on a cutting board, inside a floor drain or under a countertop-mounted piece of equipment.
What most people in foodservice don’t understand is that there is much more to slime than meets the eye. Unless you want to risk getting “slimed out of business,” you need to address that slime as the menace it is and not just as a cleaning chore.
What we typically refer to as slime is actually biofilm, which is defined as a collection or community of bacterial cells. Often those bacteria are the bad variety, such as E. coli or salmonella, which can both cause foodborne illness.
In a foodservice environment, bacterial cells that have not been removed through proper cleaning and sanitizing procedures can stick to one another and to surfaces. Attempts to remove them sets off a reaction: They become stressed or threatened, then send out chemical signals to other bacteria in the area and generate a glue-like material (actually a complex sugar) that helps them stick together and launch a protective “shield” against the next attempt to kill and remove them. The longer this is allowed to continue the more difficult it is to correct.
Biofilm can develop on a variety of surfaces despite thorough cleaning and is easily spread. If biofilm is allowed to form on a cutting board, for example, the pathogenic bacteria will survive recommended normal cleaning and sanitizing. If a biofilm is present and salmonella from a nearby food contact surface is then wiped off of the surface, but over the biofilm, the biofilm will capture some of the salmonella bacteria. There it will not only survive but grow or reproduce within its new safe haven.
What can you do about it?
As with many food-safety hazards, the best way to deal with biofilm is to prevent it from taking hold in the first place. If you notice a hint of slime anywhere in the foodservice operation, don’t ignore it—attack it. Sometimes our senses can detect the start of its formation. Visual signs may be a “rainbow” appearance on a stainless steel surface. A normally clean-feeling piece of equipment may feel slimy to the touch. A sour or off smell doesn’t prove the presence of a biofilm, but it could be a warning sign; it generally is a sign of improper cleaning, which could lead to biofilm formation.
As a biofilm is forming, it is still very vulnerable and can be removed with some extra effort. Once it has been allowed to develop, which may only be 24 to 48 hours, it moves into another stage that makes it much more difficult to eliminate. We also know that biofilm can establish itself more readily on rough or irregular surfaces, such as a pitted or chipped cutting board or a damaged food prep counter. This is just one more reason food codes specify that food contact surfaces must be smooth and easily cleaned.
Steven Sklare, REHS/RS, CP-FS, LEHP is an Everclean Strategic Business Development Executive that has been working in the food safety industry for over twenty years providing food safety audits and training, supply chain risk management, food safety management plan design and pest control services. Contact Steven via LinkedIn and email firstname.lastname@example.org.