FDA writes to infant formula manufacturers urging them to tighten supplier oversight

The US Food and Drug Administration (FDA) has urged infant formula manufacturers to tighten supplier oversight after botulism outbreaks and a contaminated ingredient triggered recalls across multiple markets.

In a letter issued on 13 July, the regulator called on manufacturers and supply chain partners to examine where ingredients originate, how suppliers produce them and whether existing controls adequately protect infants.

The intervention follows two multistate infant botulism outbreaks associated with powdered formula and a separate contamination incident involving nearly 150 suspected and confirmed cases of cereulide intoxication across 10 countries.

Experience has shown that ignoring or downplaying these safety signals can lead to increased risks to infants and preventable public health events.”

FDA

Outbreaks expose ingredient risks

The FDA investigated infant botulism outbreaks associated with powdered formula from ByHeart and Nara Organics, prompting both companies to issue voluntary recalls.

Investigators detected Clostridium botulinum in organic whole milk powder used by ByHeart. Two samples from one ingredient lot matched a clinical sample and an infant formula sample through whole genome sequencing.

Organic West Milk supplied the ingredient and also supplied Nara Organics, according to the regulator. The FDA continues to investigate the root causes of both outbreaks and any links to shared suppliers.

The agency also pointed to a global contamination event between late 2025 and early 2026 as evidence of how a single ingredient can disrupt formula supply chains across several markets.

Authorities traced nearly 150 suspected and confirmed cases of cereulide intoxication to contaminated arachidonic acid oil, commonly known as ARA oil, used in infant formula. The incident triggered downstream recalls worldwide and led the FDA to place products from an ARA oil supplier on import alerts.

FDA presses manufacturers to act faster

Against this backdrop, the FDA told formula businesses to assess the hazards associated with every ingredient rather than rely solely on supplier assurances or previous audit results.

Manufacturers should also monitor recalls, outbreak investigations and import alerts for early signs that an ingredient or supplier may pose a risk.

In the letter, the FDA said: “Experience has shown that ignoring or downplaying these safety signals can lead to increased risks to infants and preventable public health events.”

The agency expects companies to set clear ingredient specifications, audit suppliers regularly and isolate materials that fail safety or quality checks. It also wants manufacturers to update risk assessments as soon as regulators or industry monitoring identify new concerns.

The agency added: “When a contaminated ingredient or supplier concern is identified, whether by FDA or through industry’s own monitoring, manufacturers are expected to act swiftly to assess and address the risk.”

The letter places greater pressure on manufacturers to verify suppliers, test ingredients and trace any suspect material through production and distribution.

Wider scrutiny of formula safety

The letter comes months after the FDA completed the largest-ever testing programme for chemical contaminants in infant formula sold in the US.

Scientists analysed more than 300 retail samples, generating over 120,000 data points. They screened powdered, ready-to-feed and concentrated liquid formulas for lead, mercury, cadmium, arsenic, PFAS, phthalates and pesticides including glyphosate and glufosinate.

Most products contained undetectable or very low contaminant levels, supporting the regulator’s assessment that the US infant formula supply remains safe. However, the FDA stressed the need to keep exposure as low as possible because newborns represent a particularly vulnerable population.

The testing forms part of Operation Stork Speed and the FDA’s Closer to Zero initiative, which aim to strengthen formula oversight and reduce contaminant levels in foods consumed by infants and young children.

FDA signals continued enforcement

While the FDA acknowledged the difficulty of controlling spore-forming microorganisms in formula ingredients, it said manufacturers may need several complementary safeguards.

The agency plans to work with industry, academics and international scientific bodies to identify best practice while continuing its outbreak investigations. However, it also made clear that collaboration would not replace enforcement or manufacturers’ responsibility for ingredient safety.

The agency concluded: “The FDA will continue to use all available tools to protect infants, and we expect industry to uphold these standards to meet that commitment with the gravity our shared responsibility demands.”