When a foodborne illness outbreak hits, every hour counts. The FDA doesn’t have time to sift through stacks of paper invoices or call up dozens of suppliers. That’s where lot number tracking comes in - a system designed to find contaminated food in hours, not weeks. The key? The Traceability Lot Code (TLC), a unique identifier attached to high-risk foods from farm to shelf. This isn’t just a label. It’s the backbone of how the FDA pins down exactly which batch of spinach, eggs, or nut butter made people sick - and who handled it along the way.
What Is the Traceability Lot Code (TLC)?
The TLC is more than just a code. It’s a mandatory, standardized way to track food across the supply chain. Under the FDA’s Food Traceability Rule (FSMA 204), companies that handle foods on the Food Traceability List (FTL) must assign a TLC at three critical points: when raw agricultural products like leafy greens are first packed, when seafood is received on land, and when food is transformed - like when tomatoes are chopped into salsa or milk is turned into cheese. Unlike old-style lot codes that companies used internally for quality control, the TLC must be passed along unchanged through every step, from grower to distributor to retailer.
It can be alphanumeric - think "20260227-LG001" or "XK9-784-2026" - but it must be unique to that specific lot. A single lot might include 10,000 bags of romaine from one farm, all packed on the same day. If one bag turns out to be contaminated, the TLC lets the FDA trace every other bag from that same lot, no matter where it ended up. The code doesn’t change unless the food is physically altered. That’s the rule. No shortcuts. No re-coding for convenience.
How the FDA Uses TLCs During Outbreaks
When the CDC reports a spike in E. coli cases linked to romaine lettuce, the FDA doesn’t start guessing. They call the first retailer in the chain and ask: "What’s the TLC on your affected product?" That one code unlocks a digital trail. The retailer responds with the TLC, the date received, and where they got it from. That supplier then provides the TLC they received, and so on - back to the farm. Each step is recorded in electronic records that must be available within 24 hours of an FDA request. No delays. No excuses.
This system cuts tracing time from an average of 10 days to under 48 hours. In a 2021 pilot program, the FDA traced a contaminated onion shipment from a warehouse in California to a single processing plant in Texas in just 17 hours. Before the TLC system, that same investigation took 11 days. Faster tracing means fewer people get sick. The FDA estimates the rule could reduce foodborne illnesses by 20-30% over time.
The Foods Covered - And the Gaps
The FDA didn’t apply this rule to every food. They targeted the highest-risk items based on outbreak data. The Food Traceability List includes: leafy greens, tomatoes, melons, onions, fresh-cut fruits and vegetables, cheeses, eggs, nut butters, and certain seafood like shrimp and tuna. These foods make up about 15% of the U.S. food supply but cause nearly half of all foodborne illness outbreaks.
But critics say it’s not enough. Melons were added late, after a 2022 outbreak linked to whole cantaloupes sickened over 100 people. Consumers Union and other groups argue that other high-risk foods - like sprouts, raw milk products, and ready-to-eat deli meats - should be included. The FDA is reviewing these now. Commissioner Robert Califf confirmed in May 2023 that melons and certain ready-to-eat foods are under active consideration for the next round of updates.
How Companies Implement TLCs
Most companies didn’t start from scratch. They adapted what they already had. The FDA made it clear: your existing lot code can be your TLC - if it meets the rules. A large dairy processor might have used "L123456" for internal tracking. That code can serve as the TLC if it’s passed along with the required data. But here’s the catch: the TLC must be linked to seven Key Data Elements (KDEs): the code itself, the source location, product description, quantity, unit of measure, date of each transaction, and who received the food.
Large companies mostly updated their ERP systems - 72% of them, according to a 2023 survey. Smaller firms, especially farms and local packers, often use spreadsheets or specialized traceability software. The FDA offers free training modules and a Traceability Assistance Program to help small businesses. Still, challenges remain. A 2023 survey found 65% of companies struggled with integrating old systems, 58% had trouble training staff, and 71% said keeping partners on the same page was the hardest part.
Why This System Is Different
Before the TLC, traceability was a patchwork. The Produce Traceability Initiative (PTI) encouraged case-level labeling using GS1 barcodes, but it was voluntary. Many companies followed it - but not all. The Drug Supply Chain Security Act (DSCSA) tracks individual drug packages with serial numbers. The TLC is different. It’s mandatory, it’s lot-based (not item-based), and it’s focused only on foods with the highest risk of causing outbreaks. It doesn’t try to track every single item - just the batches that matter most.
It’s also not blockchain. While big retailers like Walmart and Kroger use blockchain to track leafy greens, the FDA doesn’t require it. The TLC works with simple electronic records - CSV files, databases, even scanned PDFs - as long as they’re sortable and exportable. The goal isn’t flashy tech. It’s speed and reliability.
What’s Next?
The original compliance date was January 20, 2026. But in September 2023, the FDA proposed a 30-month extension to July 20, 2028, after hearing from industry that many companies needed more time. The agency is also working on standardized data formats for KDEs, with a draft expected in mid-2024. This will help different systems talk to each other - a big hurdle right now.
Long-term, the FDA is exploring how IoT sensors and real-time data from farms and warehouses can feed into the TLC system. Pilot projects are already testing temperature and location tracking linked to TLCs. The 2023 Farm Bill allocated $25 million to help small farms comply. International alignment is also in the works. The EU’s Digital Product Passport uses different standards, but the FDA held its first joint workshop with European regulators in March 2023 to start syncing up.
The system isn’t perfect. Critics say it’s still too fragmented. But it’s the most significant upgrade to U.S. food safety since the 2002 Bioterrorism Act. And for the first time, there’s a real, enforceable way to find the bad batch - fast.
What foods are covered by the FDA’s Traceability Lot Code system?
The FDA’s Food Traceability List (FTL) includes high-risk foods such as leafy greens, tomatoes, onions, fresh-cut fruits and vegetables, cheeses, eggs, nut butters, and certain seafood like shrimp and tuna. These were selected based on their history of causing foodborne illness outbreaks. The list covers about 15% of the U.S. food supply by volume. The FDA is currently reviewing whether to add melons and certain ready-to-eat foods in the next update.
Do all companies need to use the same format for their lot codes?
No. Companies can use any alphanumeric format for their Traceability Lot Code (TLC) as long as it uniquely identifies the lot within their records and meets FDA requirements. Many use formats like Julian date plus product code (e.g., "20260227-LG001") or randomized codes. The key is consistency - the code must be passed unchanged through the supply chain and linked to the required data elements.
How quickly must companies provide records to the FDA during an investigation?
Companies must provide all required records - including the Traceability Lot Code and its linked Key Data Elements - within 24 hours of an FDA request. This applies to all entities handling foods on the Food Traceability List, from farms to retailers. Electronic records must be sortable and exportable in common formats like CSV to meet this requirement.
Can a company use its existing internal lot code as the TLC?
Yes. The FDA explicitly states that any existing lot code a company already uses can serve as the Traceability Lot Code, as long as it’s passed along the supply chain and linked to the seven required Key Data Elements. There’s no need to create a separate code. This was a major clarification after industry concerns about "tandem coding." The goal is to reduce burden, not add complexity.
Why was the compliance date extended to July 20, 2028?
The FDA proposed the extension in September 2023 after receiving widespread feedback from industry that many companies - especially small businesses - needed more time to implement the system. Integrating new tracking processes into legacy software, training staff, and coordinating with suppliers took longer than expected. The extension gives businesses more time to adapt without risking enforcement actions before they’re ready.