Food Safety: Tapping the dangers
There’s more to it than that. Drains are a vital part of sanitation and hygiene in meat-processing facilities. In fact, they can be the most important part of a sanitation plan.
“Drains need to be in the top list of the larger sanitation plan since drains are the one focal point where all the cleanup water moves into the wastewater system,” says John E. Johnson, managing director of the Epsilon Industries consultant firm in Sioux City, S.D.
In the past drains were not evaluated as a point of sanitation, says Johnson. The only time they were addressed was when they were clogged during cleanup. Clogging normally was because of a poor, dry cleanup, leaving solid reside to block the drain. Blocked drains can be a breeding ground for a number of bacteria because they present a very good medium for microbial growth.
Elizabeth Boyle, Ph.D., a professor of animal sciences and industry at Kansas State University in Manhattan, Kan., says that drains can be a harborage site for Listeria monocytogenes. When traffic moves across drains, whether it is foot traffic, forklifts, smokehouse carts, or other mobile objects, moisture or water droplets from the drains may be translocated and cross-contaminate other areas of the processing facility. If hose spray is inadvertently directed toward a drain during cleaning operations, water from the drain can be atomized into the air from the drain potentially misting the area with Listeria.
“Drains have long been recognized as a source or reservoir of bacteria,” says John Butts, vice president of research at Lansing, Ill.-based Land O’ Frost. “Ten to 15 years ago, microbiologists believed drains were almost always going to be Listeria positive.”
The perception of drains has been that they were “unmanageable,” he continues. That has changed with the current emphasis on sanitation process control in high-risk ready-to-eat (RTE) production areas such as those for sliced meats and hot dogs. New techniques to manage the sanitary condition of drains and the floors around drains have been developed.
“Numerous plants have gone for extended periods (greater than one year) without a Listeria species positive in an exposed product RTE drain,” Butts says. “We now have the ability for the microbiological control of drains.”
Boyle adds that cleaning and sanitizing drains need to be part of the picture if they are not already.
“They need to be maintained to prevent backups and flooding in the area surrounding the drains, floor cracks around drains should be sealed, and in general, the floor area around a drain should be kept fairly dry in RTE areas,” she says.
Because a plant will have written sanitation standard operating procedures (SSOPs) for the facility, procedures should be included in those documents for cleaning and sanitizing drains, says Boyle. Plants that produce RTE products need to consider the impact of drains in their sanitation strategies for Listeria control in the plant environment and include alternatives.
“The drains need to be designed for specific areas in which they will be utilized,” says Johnson. “Drains should not have any seams or niches where water can stand.”
Renovations or additions often do not consider drains or the flow of water during the cleanup process in a facility, says Johnson. Modernizing the drain system costs capital, and some plants do not have that available, especially during tough economic times. Drains could be updated relatively easily by cutting the old drains out and replacing with new, seamless drains.
“A complete drain system should be designed from the wastewater facility back into the plant to determine the correct amount of capacity and flow,” he says. “Properly sized pipes, the right connections and ability to service the drain system are critical.”
Butts says drain control is one of the most important factors in Listeria control program in RTE plants today, adding that drains and the surrounding floor area should be a part of the routine Listeria monitoring program.
“Drain sites are commonly monitored by [the U.S. Department of Agriculture’s Enforcement, Investigations, and Analysis Officers] when performing IVT or RLm sampling audits,” he says. “Best practices have been established to enable the risk from drains and drain systems to be minimized to a controllable level in ... exposed product areas.”
New waysAccording to Boyle, researchers at the University of Georgia have identified several strains of bacteria that provide a competitive environment against Listeria. By incorporating these strains into foam, the researchers found they were very effective in eliminating Listeria in food plant drains in the study.
“Plant operators should keep current on new technologies that come out of this type of research that could be used to improve sanitary conditions in the plant environment,” she says.
Effective drainage is, in fact, a requirement for the sanitary conditions of facilities under the USDA’s Food Safety and Inspection Service (FSIS) guidelines. All drains, and gutters as well, need to have properly installed traps and vents that have been approved by the plumbing circuit supervisor. Interceptor traps which are connected with the sewer system need to be suitably located, and not near any area where food products are loaded or produced. To facilitate cleaning, such traps must have inclined bottoms and have suitable covers to maintain hygiene.
The FSIS regulations also say that each floor drain shall be equipped with a deep seal trap, and the plumbing shall be installed so as to prevent sewage from backing up and flooding the floor, except that floor drains in areas not regularly washed down will be acceptable without deep seal traps. However, drains for those areas must connect to secondary drainage systems that discharge into a safe sink or basin that is properly trapped and vented.
Johnson says there are a number of companies that can fabricate drains. The best designs allow water to flow quickly, avoid pooling and prevent solids from entering the drain system that can create backups. In fact, he says the biggest challenge in the real world is making sure the sanitation crew cannot pull the catch baskets from the drains. Some plants weld the baskets in place to prevent this.
“Don’t overlook the drains,” says Johnson. “The last thing you overlook could be the first thing that causes you a problem.”