William Stoddard
Pioneering Ozone Disinfection Technology

William Stoddard is President and CEO of Cylopss Corporation, a world leader in the development of ozone sterilization/disinfection technology. In a mere nine years his company—and its technology—has grown from a single-application entity (the sterilization of medical instruments) to a multi-faceted corporation serving the medical, biochemical, textile, water reclamation and food services industries, offering innovative disinfection systems based on the use of ozone. It is a technology, says Stoddard, that “can be made on site, has a very short life, has no environmental consequence and leaves nothing behind on the food for the consumer. There is no waste product other than oxygen.”

FoodTechSource: How long has ozone technology been available?

William Stoddard: As a disinfection agent, it’s been in use for probably as long as 90 years. It’s been used predominantly for municipal water disinfection The city of Paris has been using it for their municipal drinking water for probably as long as 70 years. In fact, the six largest municipal water treatment facilities in the world use ozone as a primary source of disinfection. Over 90% of all bottled water is ozonated. In fact it’s been in use in the bottled water industry for almost 18 years in the United States. Its flawless safety record is one of the reasons the FDA to be so comfortable with ozone’s use in food processing.

FTS: Is that based on FDA studies or the results of usage?

Stoddard: Principally usage. There are 1 billion gallons of water consumed every day in the bottled water industry and there have been no adverse effects. In fact, the department of health for the city of Los Angeles just released a study showing that if you are a pregnant woman and you drink over five glasses daily of chlorinated drinking water produced out of the LA County water district, you increase your chances for miscarriage by almost as high as 20%. For the control group that consumed bottled water the figure was roughly 10% of that. It has to do with trihelomethane chlorinated composites that are residuals. Ozone leaves nothing behind in its oxidation process because it converts back to oxygen so it leaves no long-term chemistry behind it.

FTS: How does ozone decontamination work?

Stoddard: Ozone is a unique antimicrobial agent. In fact it is the most aggressive oxidating antimicrobial agent known to man. Ozone is formed by applying electrical energy to the oxygen molecule, which splits some portion of those oxygen molecules in half, into singlets of O. Those single O atoms attach to O2 for a very short time period, becoming O3, which has a half life in its natural state of about 20 minutes before, on its own, it converts back to oxygen by releasing its singlet of O. During that active phase as ozone, it reacts to any organic compound by oxidizing double carbon bonds. So unlike a lot of other disinfection sterilization technologies, in the act of literally taking a cell membrane apart, in destroying the cell, it converts itself back to oxygen which is a very benign waste product. If you look at water that has been disinfected with a chlorinated compound versus ozone, you’ll see dead microorganisms in the chlorinated water. If the water has been treated correctly with ozone you should literally see nothing because it should break it down to just its basic elements which are hydrogen and CO2.

“Ozone is the most aggressive oxidating antimicrobial agent known to man. But in destroying the cell it converts back to oxygen—a very benign waste product.”

FTS: Why haven’t we seen its use in the food arena before this?

Stoddard: It’s been used extensively in South America and in Japanese communities. Also in Europe for long term meat storage and some other applications. It hasn’t been used broadly in the U.S. because chlorine and hydrochlorides have offered effective and inexpensive methods for treating the bulk of wet processed foods, like fresh produce and poultry, and ethylene oxide and methyl bromides have been used in a gas form for those products treated in a dry state, like spices, teas and berries. But the public is finding out that these technologies have a price attached: food disinfected by these means carry, among other things, traces of trihelomethide, a chlorine derivative linked to breast cancer, rectal cancer, colon cancer and miscarriages. Ethylene oxide is a known carcinogenic. Methyl bromide, is a key ingredient for mustard gas.

FTS: The public is also concerned that these technologies may not be working as well as they should. Simply microorganisms like cryptosporidium now have a high resistance, even an immunity to, chlorine. A couple of years ago they had a big cryptosporidium outbreak in Milwaukee...they’re having the same problem right now in Sydney, Australia. But with ozone, because of its unique method of kill, microorganisms cannot build up an immunity. It doesn’t interact with DNA—it literally take the microorganism apart. So it has the ability to be a one-time fix, and has the added benefit in that it has no environmental consequence.

FTS: What is the downside? The expense?

Stoddard: It’s been very expensive. Ozone is made with electricity, and because of the amount of energy needed for the amount of ozone produced, it has historically been relegated to large industrial applications...water treatment, pulp bleaching, those type of things. But we’re making advances very quickly. The computer-controlled manufacture of ozone is getting more and more inexpensive. So the economics are starting to make sense. Especially given the increased economic costs of dealing environmentally with these other products. For example, chlorine contamination of ground water has become a major issue. Chlorine and ethylene oxide have been banned in a lot of countries. Methyl bromide will be banned in the U.S. in 2001. So, alternatives need to be found.

FTS: What kind of reception are you getting from the general public? Do they think that ozone use could lead to further depletion of the ozone layer or lead to ozone alert days?

Stoddard: The biggest problem we have is education. It’s a little known technology and the word ozone does not necessarily conjure up positive images. The June ’98 issue of Agricultural Outlook, a magazine put out bimonthly by the USDA included results of a survey they’d done in five major metropolitan areas across the country in which they asked typical consumers whether they preferred their food was treated with irradiation, chlorination or ozonation—and after the consumers were told the benefits and issues surrounding each method, 80% chose ozonation. Once people become aware that it’s not just pollutants in Los Angeles, they embrace the technology.

FTS: What is the equipment itself like? Is there different machinery for each food type? Do you spray water? Is it gaseous? What?

Stoddard: We’re moving through a lot of revolution right now in product design. The systems we are currently operating are primarily chlorine replacement in wet produce applications—citrus or tomatoes or potatoes or vegetables. Traditionally, when produce comes in out of the field, it is put in large flumes that are like large artificial rivers. This is used for transport and to wash off dirt, pesticides, and any organisms that are on the surface. This requires enormous volumes of water, which gets reused due to water conservation. And in each reuse, more chlorine is added, which creates quite a soup—you basically end up with Clorox. And getting rid of that water now becomes an issue because the municipalities don’t want to take it and you can’t just go back out and spray it on a field. What we’ve been successfully able to do is literally put water in a loop that can be used and not replaced. The technology is available to safely filter out the organics, and the ozone expends itself in reacting with the microorganisms. So, our reused water contains nothing but oxygen. Tremendous savings in resources.

“The biggest problem we have is education. Once people realize ozone is not just pollutants in Los Angeles, they embrace the technology.”

FTS: Is that the only application thus far?

Stoddard: We’re developing a poultry application, in the chiller water area. They currently use chlorine dioxides in chiller baths, which are used to lower the temperature of the product, and the water needs to be continually replaced because it gets contaminated with organics and with increased levels of chlorine. We’ve designed a system that will allow the refrigerated water to be used repeatedly through the entire day—which offers tremendous energy savings because you’re not having to refrigerate and replace 50,000 to 60,000 gallons of 32-degree water every 4 or 5 hours.

For dry applications, we have a joint venture operation with a large produce company to treat ripening rooms, to introduce ozone in very low quantities to keep molds and mildews from developing and rotting the produce. We’re also using it in a gas phase in a very large potato storage facilities where produce is kept for six to eight months. And we’ve just now entered into a research contract to use ozone in a gas phase on cuttings and trimmings of beef prior to grinding to eliminate cross contamination in the grinders.

FTS: What are the cost factors for industry? Any breakdown?

Stoddard: There’s one application that we haven’t even talked about because it doesn’t have anything to do with food technology, but we have developed systems using cold water and ozone for textile applications, including textile disinfection, that save tremendous amounts of money. We are anticipating that the same sort of economics are going to exist in the food industry. Because unlike, for example, irradiation, in which the existing physical plant has to be substantially modified in order to use the technology, and you have to ship the product a great distance to a central facility, which ties up a lot of inventory, ozone technology can literally go into any existing plant that is using water. If you’re using chlorine or chlorine dioxide, we can introduce ozone. And it is a very inexpensive conversion.

FTS: What does the machinery look like?

Stoddard: It depends upon the application. If you are treating a million and a half gallons of water a day in a prepackaged salad plant, you have a much greater requirement for substantially more ozone then a small green pepper farm in New Mexico that’s maybe only using 6,000 or 7,000 gallons of water a day in a small flume. The same with the gas application. If you are going to be dealing with introducing a volume of gas into a potato storage facility, you’re dealing with a room that is 350 feet long by 120 feet wide by 24 feet high—but it requires very low levels of ozone, because you only need the ozone to act as an inhibitor against mildew. But when we get into a situation where we are looking at sterilization, and we are trying to kill very substantial microorganisms, such as spores, then even in a small volume of air we have to get concentrations up to a very high level to be effective. And at those very high levels, we need very short exposures because of the oxidative potential of the gas. So, in this case we need large equipment for smaller dosages—it is wholly dependent upon the application.

“Safe? Your copy machine exposes you to more ambient ozone gas than you will ever be exposed to in one of our installations.”

FTS: In the potato storage facility, are we talking about something the size of an industrial air conditioning unit or something half the size of the building?

Stoddard: In those installations we are talking about a device—not including the monitoring devices from the generator itself—that is about the size of a color television and not substantially larger. With all our applications we start off with pure oxygen as a source gas, so we use oxygen concentrators. That is necessary because in the atmosphere we have a lot of other gases that could serve as pollutants and cause the system to be ineffective. The systems also include an ozone generator and a very elaborate and sophisticated process control system, because safety is an issue with this product just like anything else that’s been designed to destroy life.

FTS: If you were to be exposed to pure ozone, would it disassemble the cells in your body?

Stoddard: No, but OSHA and the EPA have set standards for long term exposure—ozone is not good for you in high concentrations, just like oxygen isn’t. On the other hand, your copy machine exposes you to more ambient ozone gas than you will ever be exposed to in one of our installations. And you’ll never hear about an ozone tanker tipping over into a river and killing wildlife 100 miles downstream.

FTS: That is a most comforting thought.

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