Most food manufacturers do not have a supply chain preventive control and will not have supplier verification in their written food safety plan. A separate blog post of mine, Supply Chain Preventive Controls, discusses identification of a supply chain preventive control.

    1. Supply chain preventive controls are required for ingredients where YOUR suppliers control the hazards.
    2. A supply chain preventive control is required for imported packaging when a hazard is identified.

The safety of imported ingredients and imported packaging is enforced under the Foreign Supplier Verification Program (FSVP) rule. See the Preventive Controls for Human Food rule for supplier verification.

I get a Certificate of Analysis (COA) with my ingredient. I’m good, right?

Good, but you are not done. The way I approach supplier verification is as an attorney collecting evidence to build a case that a jury will decide. You are the attorney, and FDA is the jury. The burden of proof is on you to demonstrate the ingredient is safe. Yes, it is all about verification. Your FDA inspector will review your supplier verification.

Before we go on to the requirements and just checking in, have you identified a hazard requiring a supply chain preventive control? If the answer is yes, read on!

Requirements for Supplier Verification

    1. Supplier approval
    2. COA or similar document with receipt of every shipment
    3. Sampling and testing for hazard
    4. On-site supplier audit

      a. Use of a qualified auditor
      b. Proof of corrective action implementation

This is an extensive list and a lot of work to prove the hazard was controlled by the supplier. Let’s look at an example with peanut butter as an ingredient in a candy bar. The peanut butter is not further processed to control hazards, and supplier verification for the peanut butter is required for the control of hazards like pathogens Salmonella and Listeria monocytogenes, aflatoxin, and physical hazards. The United States had two major outbreaks from Salmonella in peanut butter, and other nut butters are under heavy scrutiny by the FDA.

Supplier approval. The approval process is not mandated, so you have flexibility on how you determine the supplier is approved. Include the written Standard Operating Procedure (SOP) for supplier approval in your food safety plan. You are required to document the supplier is approved. You are encouraged to complete this process before using the ingredient from this supplier. If not approved before you’re your Preventive Controls Qualified Individual (PCQI) must document in the food safety plan the timeline and justification for later approval.

In both peanut butter outbreaks, part of the blame lies with the customers not doing enough for supplier approval and verification. If you are purchasing an ingredient in which the pathogens are killed, the supplier is required to use a validated process preventive control. Ask for the results of the validation study and documents proving the process is validated, monitored and verified. Some suppliers are not willing to share this information. If a supplier is not willing to share food safety data, you may want to start searching for another supplier. Will you share with your customers?

Written procedures are required for Receiving for ingredients with a supply chain preventive control.

Specifications and COAs. Once the supplier is approved, you will set specifications for the absence of the hazard; that would be the absence of Salmonella and Listeria in the ingredient of peanut butter in our example. When the peanut butter is received, the Receiving personnel should inspect the vehicle for sanitary conditions and the containers to ensure they are intact. The bill of lading is checked against the goods received upon arrival. Every shipment of peanut butter must include a document stating the hazard is absent. With every shipment received, you get a COA, a Certificate of Conformance (COC), or letter of guarantee regardless of repeating a lot code. The ingredient container or pallets should be clearly labeled at Receiving, then moved and stored in a manner to prevent cross-contamination and cross-contact.

You cannot continue to just file away COAs for ingredients where a hazard is controlled by a supplier.

Sampling and testing. FDA requires verification of COAs at some frequency determined by you. Are you still with me that this is for ingredients where the hazard is controlled by the supplier? Develop a sampling plan for each ingredient to include:

    • who is responsible for sampling and how they are qualified,
    • the location where samples are taken,
    • the methods for sampling and shipping,
    • the number and size of samples,
    • the coding of samples,
    • the exact location of the laboratory, and
    • the method of the test.

Often the customer drives the sampling plan and orders too many samples and too many tests. Please do not order tests where you do not use the data. Don’t get me started on this! As the customer, you must be confident in samples being taken and shipped properly. You must trust the results of the laboratory. Work with experts to develop your sampling plan.

On-site audit. At first glance, the requirement for an on-site audit of the supplier seems daunting. However, you do not personally have to do the audit. You may use the audit of another body for your documentation. That means you can use the audit report from a state inspector, federal inspector, broker, consultant, or auditing firm. There is a requirement for a qualified auditor, not a certified auditor. You are required to prove to an inspector how an auditor was qualified to inspect your supplier. After the initial inspection, an annual audit is required, unless there is justification for a less frequent audit that is based on evidence. Work with a qualified auditor to put together your auditing plan. After you have agreed upon the scope of the audit and how the audit will address the hazard, you must obtain all corrective action and implementation documents to address problems.

Your job is to collect evidence to prove your case for safety. Confidence will climb for your case before an FDA inspector, when you have an approved supplier, documentation of receipt of the ingredient, verification of COAs for the hazard, and results of on-site audits.

If you want to read the requirements for supplier verification, find Subpart G in the Preventive Controls for Human Food rule. However, I recommend starting with the FDA At-a-glance document which provides a neat summary of the rule. Still not sure if you are meeting the requirements for supplier verification? The ConnectFood website has free resources, and the folks at ConnectFood are here to help! Contact us.

About the Author
Kathy Knutson, Ph.D.
Kathy Knutson Food Safety Consulting
Dr. Kathy Knutson works nationwide with food manufacturers on recall investigations, problem-solving, training, and Food and Drug Administration (FDA) compliance. After being trained in 2016 as a Lead Instructor with the FDA-recognized curriculum for Preventive Controls Qualified Individuals, she delivered over 20 workshops to industry. With over 35 years in microbiology and 15 years of full-time teaching, Dr. Knutson is passionate about training and is an effective communicator at all levels in an organization. She has taught and consulted with companies on laboratory methods, interpretation of lab results, quality assurance, sanitation, environmental monitoring, Standard Operating Procedures (SOPs), Good Manufacturing Practices (GMPs), Hazard Analysis and Critical Control Points (HACCP) and the FDA’s Food Safety Modernization Act (FSMA). As a life-long learner, Dr. Knutson is trained in prevention of intentional adulteration, a topic on the horizon for the food industry. Dr. Knutson is a contributing author at Dr. Knutson writes a food safety blog and contributes expert services to manufacturers through, an online site for writing HACCP and food safety plans. When Dr. Knutson is not traveling, she works from home in Green Bay, Wisconsin, where she lives with her husband, two sons, and an adorable Bernedoodle. Learn more about her at