U.S. meat processors are beginning to explore deep-cleaning equipment with dry steam.

By Steve Bjerklie.

Werner Diercks describes a scene he personally finds incomprehensible: "I've gone to meat plants and the owner or some other high executive is having their car detailed out in front of the plant. Then I go in to the plant and it's not clean at all - there's dirt in the corners, the drains haven't been scrubbed in a while, and are filthy. This guy is taking better care of his car than of his plant that makes food products for people to eat!  I'm not telling a story; I've really seen this."  Diercks, the CEO of AmeriVap Inc., a sanitation firm based in Atlanta, Ga., is a leading proponent of what's called "deep cleaning," a kind of super-wash for food plants, including meat and poultry operations. The technology isn't new, but it's just now gaining acceptance in the U.S. meat industry. Dry-steam deep-cleaning systems are fairly common in Europe, Diercks notes, adding that he thinks meat-plant sanitation there "is 20 or 30 years ahead of what's done in the United States." A sausage processor in Tennessee and a Land O'Frost ready-to-eat (RTE) facility are leading the way on this side of the Atlantic, both installing deep­cleaning systems within the past year. John Hilker, plant manager at Land O'Frost's Searcy, Ark., operation, says USDA's revised Listeria regulations for RTE plants, issued in November 2002, are what initially got his company rethinking plant sanitation.

What is deep cleaning and how does it differ from typical plant sanitation programs?

"Deep-cleaning is defined in our plant as a process we go through to dismantle a machine, thoroughly cleaning it with soap and water and the dry steam, and then revalidating the machine to make sure it's as clean as we think it is," says Hilker. "It's a preemptive method. The dry steam heats the metal in the machines enough to kill bacteria - to sterilize the machine, in effect."

Diercks returns to the automotive analogy. "You can take your car through the car wash, and it comes out looking pretty clean. But it just looks clean; it's not really clean in all the places the car-wash equipment can't reach. If you really want to clean your car you have to have it detailed, where they steam-clean the engine."

He continues: "Deep-cleaning is about getting down into the cracks and crevices, into the pores of materials and cleaning them out," adding, "It really depends on what is meant when someone uses the word 'clean.' You can tell a child to go clean his room, and what happens is that things get sort of pushed out of the way. That's clean to a child - a room clean enough to move around in. But that may not be clean to his mother, who's thinking that clean means vacuuming, wiping down the walls, making the bed, and so forth. When we talk about deep-cleaning, we mean getting everything clean right down to the bottom."  Traditional floor mopping and equipment wipe-downs tend to either nicely spread dirt and bacteria around surfaces or shove everything into grooves, cracks, and crevices. "You can actually do a pretty good job with a traditional sanitation program, getting maybe 99 percent of the stuff, and you're in compliance with USDA," says Diercks. "But that's still not 100-percent clean." 

Just about every surface in a meat plant is porous to some degree, he points out. But since liquid water and water-borne chemicals and soaps are a kind of solid, they cannot easily penetrate the miniscule surface pores and tiny crevices that are nonetheless large enough to harbor thriving colonies of pathogenic bacteria - water beads on stainless steel, for example. Steam, however, can penetrate these tiny openings. Moreover, since steam isn't a solid, even dry, hot steam won't short-circuit a machine's electronics.  A processor agrees with the car-wash/detailing comparison.  "What you see may be clean, and, let's be honest about it, some people in this business are shooting just for that level of clean­liness, because they're worried about what the inspector is seeing. But if you really think about getting something clean, you realize you have to go far beyond what you can see. A really clean car has a really clean engine under the hood, even though you can't see it." He says that he was a little shocked by the results the first time he tried dry-steam deep-cleaning. "I thought we had a clean plant. We never got dinged by USDA for lack of cleanliness. But I learned that, well, there's more to the idea of what's clean than what meets the eye. I have to admit that before we were deep-cleaning, we probably weren't as clean a plant as we could've been."

At Land O'Frost, deep-cleaning is done machine by machine, usually on the last workday of a week Hilker says he and his sanitation staff had tried various other sanitation methods, including high-pressure wands, but found deep-cleaning with dry steam to be "very simple to use.  We didn't have to specially train anyone."

"Dry steam" is actually the vapor produced by pressurizing the steam that results from boiling water. For certain heavy-industry applications, such as scrubbing petro-chemical refineries, dry steam can be pressurized and super-heated to hotter than 500°F While dry-steam temperatures in meat plants don't have to be that high, the tem­perature is high enough so that not only are surfaces scrubbed immaculately clean by the steam, but pathogens are killed on contact. When steam is put under pressure it becomes "drier" and hotter, and the hotter it is, the bet­ter the steam is able to loosen particles and pry them out of tough-to-reach places. The process is somewhat simi­lar to what happens in an autoclave, used in medical facilities to sterilize instruments. AmeriVap, which manufactures systems of different sizes and has installations in a wide variety of industries, including the meat and poultry industry, typically combines heat, moisture, and pressure at 200°F, five percent moisture, and 60 psi maximum pressure. The temperature is high enough to kill bacteria but won't melt synthetic materials (such as air-line hoses), and the pressure is high enough to scrub surfaces without damaging them. The low moisture content, notes Diercks, does not create residual heat on surfaces because the dry steam evaporates quickly. ("Think of a hot tub and a sauna. The water in a hot tub, which is around 106° or 108°F, creates residual heat, but the much hotter air in a sauna does not.")

As noted, Land O'Frost deep-cleans its machines unit by unit - "We don't ever completely shut the plant down," laughs Hilker. Tenting the equipment during a deep-cleaning keeps the heat in, enhancing sterilization. An advan­tage dry-steam applications have over some chemical sanitation equipment is that there's no risk of over-spraying into another plant area with the steam; it simply evaporates.

Why has dry-steam deep-cleaning been slow to catch on among U.S. processors compared to processors abroad? One factor is price: these systems aren't cheap, beginning at a few thousand dollars. For a multi­plant company that's likely processing for a low-margin, high-competition market, the investment would be significant, with no opportunity to build the cost into finished products. More significantly, Diercks be­lieves many U.S. processors see sanitation as a necessary, unavoidable cost that brings them nothing in return except, if a plant is kept clean, perhaps a reduction in grief from USDA. "Cleaning does not make you money," he states. "That's the problem."

But he and others are seeing what Diercks calls "an industry behavioral change." At Land O'Frost, Dr. John Butts, vice president of research at the company's Lansing, Ill., headquarters, has been a vocal advocate for and implementer of improved sanitation. A frequent speaker at the Listeria workshops hosted by the American Meat Institute Foundation, he treats RTE operations, especially, as high-risk situations requiring nth-degree attention to detail when it comes to sanitation and cleanliness. After not being entirely happy with various sanitation schemes tried in Land O'Frost's Searcy plant, Butts and plant manager Hilker found AmeriVap back in 2002 in the course of some Internet hunts.

"I'm biased, of course, but I think this industry should be deep­cleaning all the time," comments Diercks. "I've met some processors who perceive they are deep-cleaning, but they really aren't. In fact, some­times I wonder if people really understand what clean is. What Land O'Frost is doing, though, is real deep-cleaning. They've got a sophisticated approach, and I think they treat sanitation with a very healthy respect." Hilker says the results are in the Searcy plant's records. "We haven't had an environmental or surface violation from USDA in a long time," he boasts.    MP