Lot Number Tracking: How the FDA Identifies Problem Food Batches

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.

Once assigned, the TLC must stay with that batch until the next transformation. If a processor turns whole onions into diced onions, they must create a new TLC for the diced product - but they must also link it back to the original lot code. This creates a clear chain of custody. No more guessing which truck carried the contaminated batch or which supplier provided the bad batch of spices.

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

It’s also mandatory. The Produce Traceability Initiative (PTI) - a voluntary industry effort - never achieved full coverage. The TLC system is enforced. Companies that don’t comply risk fines, recalls, or even shutdowns.

Industry Challenges and Real-World Hurdles

Despite its benefits, the system isn’t easy to implement. A 2023 survey found that 71% of companies struggle to ensure all supply chain partners use TLCs correctly. Small farms and processors face the biggest hurdles. Many still rely on paper logs or outdated software that can’t handle the new requirements.

One major complaint? Tandem coding. Companies had to maintain both their old internal lot codes and the new TLC - doubling the work. The FDA responded by clarifying that any existing code can serve as the TLC, as long as it meets the requirements. That helped - but many businesses still spent thousands upgrading systems.

Large companies like Walmart and Kroger already use blockchain systems that go beyond the FDA’s rules. But for smaller players, options are limited. About 72% of large firms modified their ERP systems. Smaller ones either bought traceability software (21%) or stuck with manual tracking (7%). The FDA offers free training modules and a Traceability Assistance Program for small businesses, but awareness is still low. A 2023 Government Accountability Office report found only 42% of small and medium businesses knew about the rule.

The Future of Food Traceability

The FDA isn’t stopping here. In May 2023, Commissioner Robert Califf said melons and ready-to-eat foods are under review for inclusion on the FTL. That would expand the system to cover even more high-risk items. The agency is also working on standardized electronic data formats, expected in mid-2024, to make record-sharing smoother across platforms.

New technologies like IoT sensors and blockchain are being tested in pilot programs. Imagine a temperature sensor on a pallet of cheese that automatically logs conditions during transport - and links that data to the TLC. That’s the next step.

Internationally, the EU is rolling out its own Digital Product Passport system. The FDA is now talking with global regulators to align standards - because food doesn’t stop at borders. A contaminated batch of onions in the U.S. can end up in Canada, Mexico, or Japan.

What You Need to Know

If you’re a consumer, this system means faster recalls and fewer contaminated products on shelves. If you’re in the food industry, compliance isn’t optional. Even if you’re a small farm or local distributor handling leafy greens or eggs, you need a TLC. Don’t wait until January 2026 - the FDA has proposed pushing the deadline to July 2028, but delays won’t make the problem go away.

Start by checking if your products are on the Food Traceability List. Then map out where in your process you assign lot codes. Make sure your code is unique, consistent, and tied to the required data. And if you’re unsure - reach out. The FDA’s training resources are free, and industry groups like United Fresh and FMI offer workshops.

This isn’t about bureaucracy. It’s about safety. Every lot number is a thread in a web that protects your family’s health. When the system works, no one has to wonder if the salad they bought is safe. And that’s the real win.