When a foodborne illness outbreak hits, every hour counts. The FDA doesn’t have weeks to track down where contaminated lettuce or eggs came from. That’s where lot number tracking comes in - a system designed to cut response times from weeks to hours. Under the FDA’s Food Traceability Rule, companies handling high-risk foods must use a Traceability Lot Code (TLC) to link every batch from farm to fork. This isn’t just paperwork. It’s a lifeline for public health.
What Is a Traceability Lot Code (TLC)?
A Traceability Lot Code isn’t your typical internal batch number. It’s a unique, standardized identifier assigned at specific points in the supply chain to track food that’s been flagged as high-risk. The FDA defines it as an alphanumeric descriptor that uniquely identifies a traceability lot within a company’s records - and crucially, it must remain consistent as the product moves from one handler to the next. Unlike old-school lot codes that companies used only for their own quality control, TLCs are mandatory for foods on the FDA’s Food Traceability List (FTL). These include leafy greens, tomatoes, onions, fresh-cut fruits and vegetables, soft cheeses, eggs, nut butters, and certain seafood. Together, these foods make up about 15% of the U.S. food supply by volume. The TLC ties directly to seven Key Data Elements (KDEs), like where the food was packed, how much was shipped, and who received it. If the FDA needs to investigate an outbreak, they can ask for these records - and companies have just 24 hours to deliver them electronically.When and Where Lot Codes Are Assigned
The FDA doesn’t let companies assign TLCs whenever they want. There are only three approved moments when a TLC must be created:- When raw agricultural commodities (like lettuce or tomatoes) are first packed at the farm or packing house - except for seafood from fishing vessels.
- When seafood from fishing vessels reaches its first land-based receiver.
- When food is transformed - meaning it’s cooked, chopped, mixed, or repackaged into a new product.
How the FDA Uses TLCs During Outbreaks
Before this system, investigators had to chase down paper records, phone calls, and scattered spreadsheets. One outbreak could take weeks to trace. In 2018, a multistate E. coli outbreak linked to romaine lettuce took over two months to resolve. By then, thousands were sick, and millions of pounds of lettuce were destroyed unnecessarily. Now, when someone gets sick, the FDA pulls the TLC from the patient’s food sample or a retail receipt. They use that code to trace backward through the supply chain. A single code can reveal every facility that touched the product - from the farm that grew it, to the distributor that shipped it, to the grocery store that sold it. The goal? To isolate the source within hours, recall only the affected batches, and prevent more people from getting sick. The FDA estimates this system could reduce foodborne illness outbreaks by 20-30%. That’s tens of thousands of preventable illnesses each year. In pilot programs between 2019 and 2021, traceability speeds improved by over 80%. One test showed a contaminated bag of spinach traced back to its farm in under 48 hours - something that used to take 17 days.Why This System Is Different From Old Lot Codes
Many companies already used lot codes for internal tracking. But those were often inconsistent. One company might use a Julian date + product code. Another might use a random string. Some didn’t track beyond their own warehouse. The TLC system fixes that by requiring:- Uniform assignment points
- Linkage to seven specific data elements
- Electronic records that can be exported in CSV or similar formats
- Immediate availability to the FDA during investigations