Testing

Advancing Safety in Infant Formula

From the moment we identified Clostridium botulinum in our formula, we were committed to understanding how it happened and preventing it from ever happening again. What we found has fundamentally changed how we approach infant formula safety.

Quality team members in protective gear reviewing production records

What We Found

For years, the infant formula industry relied on a standard test called sulfite-reducing clostridia (SRC) to screen for a family of bacteria called Clostridia, as an early warning system for contamination.

The investigation following our 2025 recall revealed that the industry standard direct-plating SRC methodology lacks the sensitivity and specificity to detect C. botulinum at the lowest levels. The bacteria can be present at levels too low for this SRC method to catch, but high enough to make babies sick.

C. botulinum can be present at levels SRC is not designed to detect. At 100 CFU/g SRC can detect and count bacteria reliably (global standard SRC threshold). At 10 CFU/g, the lowest concentration SRC can reliably detect (scientific detection limit of standard SRC methodology). At 0.01 CFU/g, trace levels, SRC results are below the level of detection and considered negative; this is the established C. botulinum level in infant formula connected to the November 2025 infant botulism outbreak.
C. botulinum can be present at levels SRC is not designed to detect. At 100 CFU/g SRC can detect and count bacteria reliably (global standard SRC threshold). At 10 CFU/g, the lowest concentration SRC can reliably detect (scientific detection limit of standard SRC methodology). At 0.01 CFU/g, trace levels, SRC results are below the level of detection and considered negative; this is the established C. botulinum level in infant formula connected to the November 2025 infant botulism outbreak.

What We’re Doing About It

The research showed that new testing protocols were needed to be able to better identify and prevent C. botulinum contamination in infant formula. In partnership with IEH Laboratories, one of the world’s leading independent food testing and safety labs, we developed the Advanced C. botulinum Safety Protocol – a multi-layered testing approach built on two distinct methods, applied at three stages of production: ingredient-level, production-level, and post-production.

This protocol layers two unique testing methods at three stages of production. It is built on the foundation of the industry-leading global standard, “ISO Standardized Method,” together with a novel test method that was developed by IEH Laboratories specifically to aid this investigation. These are both PCR tests.

SRC remains an effective screen for many types of Clostridia, and we will continue to run it on our ingredients. By layering our new purpose-built, 2x3 C. botulinum testing protocol on top of SRC, we significantly increase the chances of detecting the specific presence of C. botulinum - down to 0.01 CFU/g.

Our New 2x3 Testing

01

ISO C. bot PCR Test

This internationally recognized PCR test looks for toxin genes or DNA sequences that produce the toxin. It indicates whether the C. botulinum toxin genes are present.

Int’l Organization for Standardization
02

IEH C. bot PCR Test

While the ISO test looks for the toxin, IEH’s PCR test looks for a caretaker gene that is present 100% of the time the toxin is. This gives us a different and accurate angle of detection.

IEH Laboratories & Consulting Group

This dual testing approach can detect C. botulinum down to 0.01 CFU/g – that’s at least 1,000x more sensitive than the SRC detection limit by traditional direct plating methodology.

Dual tests are deployed at three stages of production; all testing is conducted independently by IEH Laboratories at every stage. 1: Before production begins, dairy ingredients are tested for C. botulinum before anything is used. 2: During production, testing continues as the formula is being produced. 3: Before it leaves the facility, testing is performed on the finished good. No final product ships without 3 rounds of testing.

The work isn’t done.

This is one part of our broader Action Plan, which outlines every commitment we've made to prevent an outbreak like this from happening again.

We'll continue to share our progress on testing, our supply chain, on governance, and on every other promise we've made.

“As science evolves, so must we. New evidence shows that the industry standard sulfite-reducing clostridia (SRC) direct plating method is not a reliable enough indicator for Clostridium botulinum; we have a responsibility to acknowledge that openly and act on it.”

Dr. Devon KuehnChief Medical and Scientific Officer, MeridianMade

FAQs

Is the root cause investigation over?

The FDA has concluded its inspection of our facilities and identified no deficiencies that could explain the root cause of the outbreak.

FDA is continuing its work focused on ingredients, including the powdered milk ingredient produced by a third-party supplier where Clostridium botulinum was identified. We do not have an anticipated timeline for the conclusion of that investigation, but we continue to offer our full cooperation.

How will you test for Clostridium botulinum in your product going forward?

As part of our Action Plan, we are prioritizing developing and implementing new testing protocols.

We worked with a reputable third-party lab partner to develop a new Clostridium botulinum-specific testing protocol with heightened sensitivity to previously used protocols that will be applied to every dairy ingredient and to finished batches before they are released from our facilities. We will share more on this soon.

Is the whole milk powder the root cause of the Clostridium botulinum contamination?

FDA has concluded its facility inspections, and shared that it did not identify any deficiencies in our facilities that could explain the root cause of this outbreak.

FDA is continuing its investigation into ingredients, including the powdered milk ingredient produced by a third party supplier where Clostridium botulinum was identified.

FDA has shared their lab analysis and found genetic matches involving two positive samples of C. botulinum Type A: the first is a sample of our infant formula, and the second is a sample of whole milk powder collected by FDA from one of our suppliers.

These findings are consistent with the whole genome sequencing (WGS) analysis we conducted at IEH Laboratories, representing a concrete genetic match between the whole milk powder ingredient, finished formula, and a clinical sample from a child with infant botulism from this outbreak.

We continue to offer our full cooperation as their investigation into ingredients continues.