Cleaning Without Chemicals

March 10, 2006
Sometimes the solution is not a solution, but rather steam, gas or a silver bullet.

Driven by regulation, conscience and bottom line, processors are looking for greener solutions these days, particularly in the area of plant sanitation.

Food and environmental safety concerns coupled with high energy, water and waste treatment costs are motivating the hunt for cleaning and sanitizing systems that do not employ chemicals. Viable alternatives today include ozone cleaning, dry steam deep cleaning, cold and heated pressure wash and steam pressure cleaning.

Here's a look at the alternatives.

Light as air

Spurring the development of non-chemical cleaning technologies has been concern over such potentially dangerous by-products as dioxins and trihalomethanes, which are produced when organic matter reacts with chlorine. Chlorine is the primary chemical used to kill bacteria in water. Although used in a wide variety of plant cleaning and sanitation applications, chemical use requires multiple-step processes, including a critical rinse phase, and, often, hot water or steam.

One alternative is ozone, an often-misunderstood gas comprised of a single element - oxygen. Unlike chlorine cleaning, ozone sanitizing can be a single-step process. It produces no toxic by-products when it reacts with organic material, although levels of ozone in the ambient air must be monitored where such systems are used. Ozone is a strong disinfectant and deodorizer that is second only to fluorine in oxidizing power.

Chemists describe ozone (O3) as a simple oxygen molecule (O2) coupled with a nervous and active O1 "sidekick" atom. It tries to channel its nervous energy by hooking up chemically with anything it comes in contact with. When it can't couple with another molecule, it will join another O1 atom to form a stable O2 molecule - the reason for its relative safety. Proponents claim ozone is 50 percent stronger than chlorine as an oxidizer and it acts 3,000 time more rapidly, without the toxic risk of chlorine.

Ozone technology has held promise for food processors for decades. But who knew how to harness it?

Today, it is emerging as a versatile technology that can be used in a wide variety of applications that include disinfecting water supplies, wastewater treatment and a variety of plant cleaning and sanitation functions. Ozone systems have been approved by all the necessary food governing agencies.

"Our ozone systems are employed by some of the largest food processors in the world," says Dan Lynn, CEO of Ozone International (www.o3international.com), Bainbridge Island, Wash. He notes ozone systems are ideally suited for all protein-producing operations, including poultry and seafood, and claims some of the best results come when ozone is continuously applied to conveyor belts during production of the meat or animal protein of choice. He names Tyson Foods, General Mills, Ozark Mountain Poultry, Simmons Foods, Freshwater Fish and Kikkoman among clients.

Ozone Int'l.'s commercial ozone generator.

Ozone International's Whitewater Food Safety has two distinct applications. Water spray bars administer ozone onto conveyor belts to purge or prevent a build-up of an organic "bio-film" containing dangerous microorganisms. Intervening cleaning and sanitizing periods also take place throughout production. Through the adoption of Ozone International's HACCP Integration Program, processors have achieved the 24-hour/six day per week production.

Many companies are using ozone to neutralize biological contaminants in both air and fluid wastewater systems. Processors have used Ozone International's gaseous applications to neutralize the odor in their emissions, which often impacted nearby towns.

"Last year, several poultry processors were challenged by government agencies for the discharge of excessive amounts of suspended solids in their wastewater streams," says Lynn, also noting that Alaska-based UniSea and other fish and seafood processors in Canada and Alaska have found the systems effective.

Sewage treatment plants often charge companies discharging into their systems on the basis of biological oxygen demand (BOD), a measurement of organic solids present in wastewater. Freshwater Fish, a Manitoba seafood processor, used an ozone system to solve a nagging problem of debris build-up on a rotary screen separating solids from discharge water. The system separates the particulate matter from the discharge by depositing water onto a rotating screen. Water passes through a 500-micron screen while capturing solids on the screen surface. Rapid build-up of matter compelled operators to shut down the system frequently - sometimes at 30-minute intervals - for manual removal of the solids. The processor installed a system from that sprayed the screen with ozonated water.

Ozone International is also working with the U.S. Dept. of Agriculture on the use of ozone to eliminate E. coli 0157:H7 contamination in hide cleaning and hide-off head cleaning.

Ozone is generated on plant sites, so it requires no storage and has an unlimited supply. It has few safety drawbacks, though warning devices must be continuously active to alert plant personnel if excessive levels of free ozone should develop.

The primary use of ozone to date has been for conveyor and equipment cleaning, wastewater treatment and odor oxidation, with growing application in air systems in welfare areas (change areas and rest rooms). But look for expanded use of the technology in the years ahead.

"In the future, ozone will be a whole-house solution, used even for pest control," says Lynn. "Our goal is to eliminate the use of chemicals in food processing, to have a big impact lowering energy usage, to reduce hot water usage significantly, and to reduce the overall volume of water, which has impact on the hydraulic load of the processor. From a cleaning perspective, we can have a big impact on the environment and on energy. Look at the ROI of companies using our systems. They are very positive in utility cost reduction and added production hours."

Getting steamed

Perhaps the most common and most easily understood non-chemical cleaning technology is steam pressure cleaning. It combines the simple age-old cleaning principles of pressure blasting to remove dirt, grime and organic matter and hot water/steam to kill bacteria.

"Most plants use hot water that comes off the boiler through hoses, using foamers, liquid chemicals and sanitation agents," says Bill Hannigan, vice president marketing for Sanitech (www.sanitechcorp.com), Lorton, Va. "We can combine everything into one step using only cold or warm tap water put under pressure."

The "wet steam" process is not a vapor process, which Hannigan says might be great for sanitizing but not for cleaning. Sanitech's system employs water that may reach temperatures of 300°F at high-pressure application.

"The traditional pressure washer spits out water at the same temperature of 140°F that it went in at," says Hannigan. "It is applied at a temperature of 2,000-3,000 psi and use four to eight gallons per minute to knock off debris. It can have great cutting power and blast a surface clean. Our system, however, uses higher temperature water (300°) and is effective in food processing applications at only 1,000 to 2,000 psi, using only 1.5 to 3.0 gallons of water per minute."

Sanitech wet steam systems come in five portable models (Mark I through V), varying in pressure capability from 1,000 to 2,000 psi. Hoses to the trigger gun control vary in length.

The high heat of water used in Sanitech systems helps break down fat tissue and other organic matter. It also kills dangerous microbes.

Most pressure wash applications, Hannigan maintains, have the negative side effect of sending dangerous bacteria such as listeria and E. coli airborne, spreading them through the plant without killing them.

"With steam, however, they are killed on contact," he says.

Sanitech counts brewer Anheuser-Busch among its customers. Cheese plants, meat, seafood processors, beverage makers and vegetable processors all use a lot of water and are candidates for the systems.

Superheating for super cleaning

In 1984, an Italian bartender working in a German bar made a "eureka" discovery while washing bar glasses. Knowing that glasses with lipstick stains were difficult to clean, he walked over to the cappuccino machine and noted the remarkable ease with which the steam from the coffee maker removed the stain. That cappuccino machine became the model for the dry - a.k.a. superheated - steam cleaning equipment sold today by Atlanta-based AmeriVap Systems (www.amerivap.com).

The system evolved today's fully developed industrial machines. The Xtreme Steam industrial system is a superheated vapor system that deep cleans and sanitizes with saturated dry steam. The unit's boiler heats water to 365°F. Steam exits the unit at 265°F at an adjustable pressure of 0 to 150 psi.

AmeriVap's industrial cleaning system uses "dry" steam to deep clean and sanitize.

Superheated vapor refers to steam created at temperatures far above the boiling point of water. Superheated vapor combines the solvent power of water with high-temperature cleaning capability. The system will kill salmonella, E. coli, botulism and listeria contaminants. System benefits include, among others, reduced need for cleaning chemicals.

"The system heats water to such a high degree that it becomes an extremely hot vapor," explains Werner Diercks, CEO for AmeriVap. "It cleans everything and won't damage the equipment."

Diercks emphasizes the difference between the system and a pressure washer. Xtreme Steam is a dry steam cleaning system. The emitted dry steam contains only five percent moisture, making it safe in sensitive areas of the plant.

"It excels in areas where you can't use water - sensitive equipment, touch screens, motors, anything electric and sensitive to water," says Diercks. "It is also effective where you have crevices and hard-to-get-to, tough-to-clean areas."

The system can be used on scales and sensors, conveyors, wrappers, slicers and dicers, feeders, gaskets, electrical panels, refrigeration systems and more.

To date, bakeries have been among the most avid users of the system, followed closely by meat and poultry processing plants and confectionery processors. Current users of the system include Pepperidge Farm, Quaker Oats, McKee Foods and Nestle.

The raw product in meat operations makes equipment and the adjacent plant area highly susceptible to bacterial contamination. Meat processors employ dry steam with a technique called "tenting" to clean their equipment.

"They throw a tarp over the equipment, fill it with steam, and hold the temperature at 180°F for 15 minutes," explains Diercks, noting that a Land O'Frost plant in Arkansas is currently using the system. "Everything is heated. [Conditions are so hot that microorganisms are easily killed.] Push steam through drains and listeria is history."

A silver bullet

Hey-oh! Silver is back!

One innovative "emerging" sanitation technology is, ironically, thousands of years old. Ancient Egyptians, it seems, used to line urns with silver to prevent contamination of the contents.

"It's a technology that sat idle for a long time," laughs Mark Massie, sales manager for Bioguard Plastics, based in St. Paul, Minn. Bioguard has a licensing agreement with AgIon Technologies to use the latter's anti-microbial technology for cutting boards and other applications in foodservice and food processing operations.

Bioguard Plastics employs the same (non-colloidal) silver ion technology used in AgIon flooring systems, caulks and sealants in its line of cutting boards for foodservice and food processing facilities. (The name derives from the terms "ion" and "Ag," the latter being the periodic table representation for the element silver.) "It's a slow-release antimicrobial agent that can be embedded in many products," says Massie. "We add it to our cutting board plastic just as you would add color."

The silver ions are held in cubes that resemble zeolite cages. Each cube contains a nanoparticle of silver with many silver ions available for reduction of microorganisms.

"Each time you cut into the surface, you expose more surface area to release silver ions," says Massie.

Visually, the Bioguard cutting boards are discernible from other cutting boards by their silver color. According to Massie, their cost is within 10 percent of comparable high-density plastic cutting boards. The biggest difference comes in the invisible battle the boards wage against dangerous microorganisms such as listeria, salmonella, E. coli and a wide range of yeasts and molds.

"The (microbial) kill is approximately 93 percent within 10 minutes after inoculation depending upon temperature, moisture and the specific target organism," explains Massie. "The key, compared to chemicals and other disinfectants, is that it works 24/7, 365 days a year."

Foodservice operators are quick to recognize the value of the boards. "But the greater potential is in food processing OEM," he adds. "Also in transport, in moving raw materials in a plant, in storage of raw meat and vegetables, and in handling or any process that involves breaking down pork, poultry and other meat or animal protein. Wherever there is a plastic component - like a conveyor or in a knife handle - there is an application for this technology."

The Clene Coat line of coatings and sealants from AgIon Technologies (www.agion-tech.com), Wakefield, Mass., are resilient epoxies thermally compatible with concrete and resistant to bacterial contamination on the surfaces of an industrial environment, explains Joe Geary, AgIon vice president for upgrade solutions.

Its core product is Clene Coat, a top coating for walls and ceilings. But food plants have countless corners that make it easy for bacteria to propagate.

"Half the problem is getting into the irregularities of shapes, floors, corners and intersections," says Geary. "That's why we have flexible caulks for expansion joints and intersections between floor and wall and wall panels. Water and organic matter in a food plant invite mold problems. Normally, caulk will harbor mold. But our caulk is a mold-resistant epoxy."

Other products in the line include a quarter-inch "trowelable" caulk to protect the underlying concrete slab; Clene Coat SL, a self-leveling coating; and Clene Seal, a light-duty sealant that protects against moisture migration while preventing bacterial growth.

"The unique theme of this product family is the antimicrobial activity of the technology," says Geary. "Ionic silver is the active ingredient, and it works against the broad spectrum of bacteria found in a food facility. We build it into the system to resist microbial growth 24 hours a day, seven days a week."

How to find the most effective cleaning method for your plant

The "food industry" is an amalgam of many food segments with varying sanitation needs. Take any given cleaning or sanitation method - whether or not it employs chemicals - and you will find a number of options to select from.

How do you pick the one best suited to your operation? Consider first the three reasons for cleaning and sanitation in a food plant:

  • Product safety -

  • Product quality -

  • Compliance with government regulations -
Plants that cannot meet required sanitation levels can be fined, closed or both.Bacteria can cause premature spoilage and reduce shelf life.
    Food products must be free from hazardous bacteria or other matter.

"Plant management should consider five elements when deciding on proper sanitation measures," says Roger Tippett, senior product development program leader for Ecolab (www.ecolab.com), the St. Paul, Minn.-based provider of plant cleaning and sanitation solutions.

  • The nature of the soil:

  • The surface to be cleaned:

  • Water supply:

  • Method of application:

  • Environmental concerns:
Will the cleaning process or discharge have an impact on worker safety, wastewater or air emissions? This includes manual, spray, foam and mechanical or clean-in place (CIP) applications. Know the quality of your water, its hardness, trace elements, etc. Some chemicals or cleaning methods may corrode the surface of your equipment or work area.
    What type of material or residue is found on your lines and facility?

Once a type of cleaning system is selected, four key application parameters come into play:

  • Time:

  • Temperature:

  • Concentration:

  • Mechanical action or force required in application:
This covers such factors as brushing or scraping action of a device or spray head as well as the pressure of a spray stream. Know at what concentrations a given cleaning agent must be used to be effective on the range of soils in your operation. Some soils may require that you apply the cleaning agent at higher temperatures - say, at or above the melting point of a fat.
    How much time will a cleaning agent require to react with the soil to effect removal?

Understanding the nature of your cleaning and sanitation challenge and the factors determining its effectiveness sets the table for effective cleaning, notes Tippett. Ecolab has developed a PLC-driven on-site formulation system, named Quadexx, which can make up to 217 formulations thereby allowing processors to pick the custom cleaning solutions they need. "No one shoe fits all," he says.

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