Walmart Is Putting Lettuce on the Blockchain

Walmart and Sam’s Club have asked their suppliers of leafy greens to start using blockchain technology to ensure “real-time, end-to-end traceability from farm to table” and to “speed up identifying, researching and reacting to food safety situations.” In a statement, Walmart said these systems are expected to be in place by September 2019. Blockchain is a record-keeping system that allows for secure data sharing. In a blog post, Matt Smith of Walmart Communications likened the blocks of information in the blockchain to railroad ties and the chain to the rail. “To place a tie on the ground, agreement is needed by … the civil engineer, the foreman and so on," Smith said. "Once the tie is placed on the ground, the rail the train travels on is placed on top. Now, imagine trying to remove and alter one of those railroad ties. It’s not that simple. The tie can’t be altered without stopping trains, removing the rails, getting agreement from the civil engineer and so on. Plus, everyone can see that you’re altering the railway, so you better make sure you get it right. There is a lot of accountability.” (For a deeper dive into all things blockchain, see Adweek's explainer.) Walmart pointed to the E. coli and salmonella outbreaks earlier this year and subsequent waste when consumers and grocers had to throw out food because they didn’t know where it came from and whether it was part of a recall. For example, in the June 2018 E. coli outbreak, the Centers for Disease Control said to avoid lettuce grown in Yuma, Ariz. “But it was difficult for consumers to know how to determine where their lettuce was grown. None of the bags of salad had ‘Yuma, Arizona’ on them,” said Frank Yiannas, vice president of food safety at Walmart, in a statement. “In the future, using the technology we’re requiring, a customer could potentially scan a bag of salad and know with certainty where it came from.” Yiannas said it can take his team seven days to track down where a product came from with traditional paper-based record keeping because they have to contact the supplier as well as the company that imported or shipped the product to Walmart’s distribution center. Blockchain tracking, on the other hand, takes just seconds and, in turn, enables consumers and retailers to respond quickly. “Enhanced ability to trace a contaminated food back to its source will help government agencies and companies to identify the source of a foodborne disease outbreak, coordinate more effective recalls of foods thought to be contaminated and learn where past problems began,” said Robert Tauxe, director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases, in the statement. “We think these steps will strengthen future prevention efforts and better protect the public’s health from the threat of foodborne illness.” A Walmart rep said the retailer has been working with IBM and food companies including Dole, McCormick and Company, Nestle, Tyson Foods and Unilever, for more than a year to develop a blockchain-enabled food traceability network. IBM and Walmart have previously worked together to trace pork in China and mangoes in the U.S.