Raw Material/Product Traceability

Features - Cover Story

Lot traceability of raw materials is not only required by the FDA and USDA, but desired by you and your supplier to restrict the amount of product potentially affected in case of a recall.

April 19, 2007

Global initiatives and U.S. regulations related to food and feed raw material and finished product tracing have been strengthened during the past few years. The FDA defines a lot as “…the food produced during a period of time indicated by a specific code.” [21 CFR 110.3(h)]. A common standard used in the industry is to restrict the size of a lot to a maximum of 24 continuous hours of production or packaging. To further narrow the amount of potentially affected product, companies may wish to further narrow the size of a lot to the best of their ability. This can be accomplished by adding a shift, hour, and/or time stamp to the finished product packages. 

SUPPLIER IDENTIFICATION. Lot traceability starts with your supplier. Due to different types of tracking requirements, there could be numerous codes on a shipping container. You should ask your suppliers to identify the system they use for documenting their lot numbers. Information from your supplier concerning their lot number system should include:

  • The code/numbering system on the shipping container used for lot traceability.
  • Location on the shipping container (if applicable) where the code is located.
  • Do words such as “lot number,” “trace number,” “date of manufacturer,” etc., precede the number?
  • Interpretation of the code used. For example:
    Is the code the date of manufacture or randomly assigned by a computer?
    Julian code followed by year or the month, day, year, time, plant identification

LOT NUMBER IDENTIFICATION. Your employees could be easily confused as to the correct number to record due to the amount and different types of codes used on a raw material. Food processing plants have identified two approaches that will help make certain the correct number is being recorded or documented.

  • Some manufacturing locations have developed a plant-specific lot number for internal tracking. This new lot is added to the same sticker affixed to each pallet used to document the date of receipt. This provides excellent opportunity to minimize the number of different types and locations where supplier lot numbers might be located. The Receiving function will be the only department necessary to train and educate where the supplier-specific lot number can be found. This system requires excellent documentation by the Receiving function to ensure cross reference between the supplier’s lot number and the plant-assigned number.
  • A second approach used by many companies is to take a picture of the supplier’s lot number and location. This information can then be posted in both the Receiving and Production areas for easy reference. This will help minimize the opportunity for confusion as to the correct number to record.

BULK/SILO STORAGE. Materials placed in a silo or bulk storage system (liquid and dry) do not stay in layers as the next lot is added. The new lot is typically blended with the existing contents during the unloading process or as the material is drawn from the silo. While this blending increases the amount of material that will be involved in the event of an issue, the identification of bulk receipts is a critical part of any lot identification/traceability program.

If there are multiple silos for the raw material, the individual receiving the shipment should document the specific silo used to store the incoming material. In addition, if multiple shipments of the same material are received on the same day, documenting the time of receipt could narrow the amount of finished product affected.

Typically, the operator who draws material from a bulk storage system will not know which lot(s) are in use. They will have to identify the lot on the batch sheets as “silo”. The receiving records then become the sole documentation of the lot. If there is more than one silo, a common practice is for the operator to circle the silo number in use.

If the supplier identifies an issue, the affected products would be from the date/time the problematic ingredient was received until the silo and affiliated equipment (use/surge bin, etc.) was totally emptied and cleaned. For example:

  • Suspect ingredient was received on January 1.
  • The silo was cleaned on January 15.
  • The supplier notified the plant of an issue on January 30.

With the above example, product from January 1 through 15 would be suspect regardless of how quickly the plant believed the suspect shipment was used.

The plant team should determine the likelihood of a possible failure and determine how often the bulk bins/silos must be emptied and cleaned. You should review your bulk ingredients and determine the level of risk you are willing to accept. Things to consider include:

  • Have there been past issues with the ingredient?
  • Have there been past issues with the supplier?
  • What are your controls after receipt, i.e., sifter, screens, a kill step, etc.?

DOCUMENTATION OF USE. The plant must develop a method of identifying what and when a raw material, including packaging material, was used. You should not rely on receiving data since raw materials may be used out of rotation.

The most common way to document raw material use is on the production records. These can be a batch sheet, production formula sheet, etc. Regardless of how it is documented, a system for tracking when you use a specific lot and the quantity used is essential. This will be used to help identify the specific finished product made with the raw material in question.

REWORK. In addition to the initial raw materials, any rework generated needs to be documented. The rework information needs to identify the product as well as the production date/shift. This will allow the plant to identify the date the rework was initially manufactured. When the rework is used, its addition (quantity added, date, and time of addition) should be documented. During a traceability exercise, don’t forget to track the subsequent use of rework.

A system for breaking the rework chain is recommended. If an ingredient in one batch is suspect, all sequential batches using rework is also suspect until a clean break has been accomplished. As with the bulk ingredients, the plant will have to determine how often this will occur.

MANUFACTURING LOSS. A common problem found in traceability is accounting for loss of raw materials or finished product. Some common losses include production loss, damaged or destroyed material, and samples. Let’s take a look at these to see what must be documented to assure appropriate traceability documentation.

First, the amount of raw material lost due to production tasks, such as start-up, flushing product that cannot be recovered, etc. You should determine the average loss that occurs during a production run. If tracking the amount of raw material received and the amount of finished product made, some of the discrepancy can be attributed to production loss.

Tracking the amount of raw material, in-process, and finished product that is destroyed not only allows you to account for raw material use, but can also be tracked to identify where improvements can be made to the process to increase productivity and decrease loss.

Samples encompass the amount of product collected for in-house analytical, microbiological analysis, customer request, etc. Ensure that the amount of product collected is accounted for. Samples are also used by the sales force or distributed to employees. Tracking the lot number, quantity, and location where samples were distributed is an additional refinement for tracking all components of the product.

The plant team may identify other locations where loss will occur. These must all be considered in the completion of a traceability activity.

SUMMARY. Lot traceability of raw materials is not only required by the FDA and USDA, but desired by you and your supplier to restrict the amount of product potentially affected in case of a recall.

Your company should periodically verify that the tracking systems being used are effective by conducting traceability exercises, both forward (finished product from production to shipping to the first point of shipment) and backward (finished product back to all raw materials used in the production). Failure to identify and trace 100% of the raw materials used and finished product produced is an indication that additional strengthening of your Traceability Program is needed. AIB

The author is HACCP Coordinator at AIB International.