Walmart Inc. expects suppliers of leafy greens to implement blockchain technology to ensure traceability and food safety. Suppliers to the retailer are expected to have programs in place by September 2019.

Blockchain technology uses digitized data that is shared in a network that is secure and trusted by all parties in the supply chain. Walmart said use of the technology will allow it to more accurately and rapidly identify food safety issues.

“Our customers deserve a more transparent supply chain,” said Frank Yiannas, vice-president of food safety. “We felt the one-step-up and one-step-back model of food traceability was outdated for the 21st century. This is a smart, technology-supported move that will greatly benefit our customers and transform the food system, benefitting all stakeholders.”

Walmart said it has been testing the technology and has successfully developed a blockchain-enabled traceability network. In the letter to leafy-greens suppliers, the retailer said it expects producers to be able to trace their products back to farms by production lot in seconds rather than days.

In explaining its rationale for implementing the program, Walmart referenced the recent multistate outbreak of E. coli O157:H7 associated with Romaine lettuce that caused over 200 illnesses and 5 deaths.

“We have to go further than offering that great food at an everyday low price,” said Charles Redfield, executive vice-president of food for Walmart. “Our customers need to know they can trust us to help ensure that food is safe. These new requirements will help us do just that.”