Tracking Food, for Safety’s Sake

How track-and-trace technologies can improve food safety

5 min read
Tracking Food, for Safety’s Sake
Illustration: Carl DeTorres


Death by spinach: They’re not words you’d expect to read in an obituary. Yet in 2006, five Americans died and more than 200 others fell ill from eating the salad greens, which were contaminated with a virulent strain of E. coli bacteria.

The U.S. health authorities were so alarmed that they instructed grocery stores and consumers all across the nation to throw away any fresh spinach they possessed. Several million kilograms of leafy greens were destroyed in an attempt to keep consumers safe—but the subsequent investigation revealed that the contaminated spinach had all come from one processing plant in California and had been bagged up during a single shift.

The public health advisory was broad because authorities couldn’t swiftly discover the source of the contaminated produce they found in sick people’s homes. Instead, U.S. Food and Drug Administration officials had to comb through thousands of pages of documents, some of them handwritten, to trace the path of the malevolent greens. It was a perfect demonstration of how broken the food safety system is, and the desperate need for technological solutions.

In fact, solutions exist. The difficulty is getting the food industry to use them.

The most obvious fix is radio-frequency identification (RFID) tags, which use radio waves (typically ultrahigh-frequency waves of about 900 megahertz) to send information to a reader. With this technology, you can tag a pallet of bagged spinach with a unique ID number when it leaves the processing plant, and electronically trace its progress through the distribution chain all the way to the grocery store. Later, if food safety inspectors find a single contaminated bag of greens, they can have the grocer determine which pallet it came from, and then trace that pallet’s path back to the source of the contamination. Then the authorities can pull just the items that shared that path. The same technologies can be used for livestock, down to the level of all the beef products that come from an individual cow.

four illustrations of tracking from pig to sausage At a hypothetical farm of the future, each pig sports a tag with a unique identification number. Those pigs are turned into pork sausages. At the processing plant, packers slap an RFID tag on each carton of sausages, which encodes those pigs’ ID numbers. Temperature sensors on the cartons continuously measure the ambient air temperature, and that information is also stored on the RFID tag. Along each step of the supply chain, the RFID tags on the cartons are scanned. The time and location data are added to the tags to create a record of when the sausages were loaded onto a truck, when they arrived at the distribution center, and so on. Finally, the grocer who receives the links can scan an RFID tag to pull up an exact record of how long the meat took to move through the supply chain and whether it was kept at safe temperatures throughout. If an outbreak of food-borne illness requires a sausage recall, regulators can use such records to track the tainted meat from the point of sale back through the supply chain to its point of origin. Illustration: Carl DeTorres

There was a lot of excitement about RFID in the 2000s. Walmart announced the most ambitious project, requiring its top 100 suppliers to equip all their pallets with RFID tags by 2005. But cost overruns and implementation glitches led the megaretailer to cancel the initiative. “RFID was talked about as this magic thing, and everybody would use it, and they’d have the best supply chains in the world,” says Ismail Uysal, director of the RFID Center for Applied Research at the University of South Florida. “It didn’t work out that way.”

The cost of tags is a big barrier for the food industry, which operates on very narrow margins. Putting a bar code on a pallet might cost the distributor a fraction of a penny, Uysal says, versus the 7 or 8 cents of an RFID tag. That price isn’t likely to change, either. “You can make the tag faster, but there’s still a lot of metal on it, so the price won’t drop much,” he says. “What will change is what you can do with the tag, and the capabilities of the tag.” That’s where the business case can be made for the technology.

One of Uysal’s current demonstration projects involves the U.S. Department of Defense’s packaged field rations. Whether they feature vegetarian burritos or meatloaf and gravy, these bagged meals typically have shelf lives of two or three years. But their expiration dates come much sooner if they’re stored at high temperatures—in the desert, for example. The military wants a tag that reveals the exact conditions a burrito has been exposed to and for how much longer it can safely be eaten.

To get that rich data set, Uysal paired battery-enabled RFID tags with temperature sensors, and used algorithms to translate the recorded temperature information into estimates of food quality and shelf life. Not only would this let the military ensure the safety of stored food, it could also help cut waste. If one shipment of rations were stored at higher temperatures than another, the quartermasters would know to ship it first, so the troops could consume the chow before it went bad.

And it’s not just the military that can reap these supply-chain advantages, says Kevin Payne, senior director of marketing for Intelleflex Corp., based in Santa Clara, Calif., which sells RFID tracking systems. He says that distributors and retailers of expensive food items like fresh berries already see this technology’s benefits. “At the moment, there’s no accountability,” he says. “If you open up the truck and pull out the berries and they’re rotting, you have no idea what went wrong or when.” Temperature data from the RFID tag can reveal exactly where the problem occurred and can also allow distributors and retailers to make smarter decisions about moving items through the supply chain.

Intelleflex is focusing its marketing on retail grocers: “Grocery stores are the captains,” says Payne, “and they can mandate that all their suppliers do this.” And, he adds, the buck stops with the stores. If a consumer eats bad flounder and falls ill, he’ll head back to the grocery store to complain—he probably won’t remember the brand of fish or know who caught it or shipped it, but he’ll know whether Whole Foods or Safeway sold it to him.

New government regulations are also pushing suppliers to improve their food-tracking capacities. In the United States, President Obama brought food-safety regulations in line with those now in force in Europe and Japan by signing the Food Safety Modernization Act, in 2011. Now federal agencies are busily drafting the final rules. Experts expect an emphasis on “one step forward, one step back” traceability, meaning that every food processor and distributor will be required to have electronic records showing where they got the product from and whom they passed it along to. Such a rule wouldn’t mandate the use of specific technologies like RFID tags or temperature sensors.

That means RFID companies must make the case for their technology—and they must band together to make interoperable systems that won’t be more of a hassle than they’re worth. Experts agree that the RFID industry has a long way to go to ensure that all RFID tags and readers can communicate and that the data can be exported easily to any of the commonly used company management systems. After all, it doesn’t matter how much data you have about that spinach of doom if no one can read it.

This article originally appeared in print as “Tracking Every Tomato.”

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