Last week I posted a draft citizen petition asking FDA to add botulinum neurotoxin-producing clostridia to the short list of organisms that powdered infant formula must be tested for before it ships, and to require that the dairy ingredients formula is made from be tested before they are used. Comments are due by Friday, October 30, 2026. Thank you to everyone who has already written. Two of the comments raise questions I do not think I should answer alone, so I am putting them to all of you.

https://www.marlerblog.com/files/2026/10/C.-botulinum-Petition-10.15.26-WDM-1.pdf

The petition will not change on these points for now. It asks FDA for what the record from the ByHeart and Nara outbreaks supports, and I want to keep it that way. But that record was built after fifty-two babies were hospitalized, and the next outbreak will not wait for a better one. If there is a case for reaching further upstream, I want to hear it before I file, not after.

Question one: should testing reach every ingredient, not only dairy?

The draft requires lot-by-lot testing of dairy-based ingredients that have not been through a validated spore-reduction step: whole milk powder, nonfat dry milk, milk protein concentrate, whey and its concentrates and hydrolysates. That is where the evidence points. FDA’s inspections found the organism in a lot of organic whole milk powder at the dryer, and when the agency went looking in powdered milk this February, it found a spore-former carrying a botulinum toxin B1 gene in two of 48 samples on the first pass.

But spores live in soil, not only in milk. Plant proteins, starches and carbohydrate powders can carry them too, and a rule that says “dairy-based” invites arguments about what counts. On the other side, ByHeart’s own testing of its non-dairy ingredients, reported to the July roundtable, came back negative, and requiring a 200-gram test of every lot of a vitamin premix that makes up a fraction of a percent of the can is a lot of cost for little protection. One middle path would presume that every ingredient needs testing unless the manufacturer documents in writing why a particular one does not and keep those records available to FDA.

So: which non-dairy ingredients, if any, belong in a testing requirement? Is a written-justification approach workable, or does it hand the decision right back to the companies that made it before?

Question two: should the milk be tested before it is ever dried?

One commenter argued that the draft does not go far enough upstream. In that reader’s view, any company drying milk into whole milk powder or other dairy powders for infant formula should test every incoming tanker of raw milk for botulinum neurotoxin-producing clostridia, on the theory that the smaller and more targeted the haystack, the better the odds of finding the needle.

The idea has real force. A tanker comes from a handful of farms on one route. Once it is pumped into a silo and dried with dozens of other loads, a contaminated delivery is diluted across a large powder lot, and the link back to the farm is gone. Reporters found that FDA traced the milk in these outbreaks to 22 dairies that have never been publicly named. Testing at the tanker would tie any positive to a small set of farms, keep that milk out of infant formula, and generate the farm-level data that nobody has today.

It also raises hard questions, and I would rather hear them answered by people who run dryers and labs than guess at them myself:

Timing. The confirmed methods for this organism take days. Raw milk cannot sit in a tanker for days waiting on a result. Does tanker testing work as a gate, or only to hold and trace the powder made from that milk until results come back?

Sensitivity. Drying concentrates whatever is in the milk, so a gram of powder represents several grams of milk. Is a sample from a tanker more likely, or less likely, to find low-level, unevenly spread spores than a sample from the powder?

Who is responsible. FDA’s infant formula rules govern formula manufacturers, not the dryers that supply them. Should the requirement sit with the dryer directly, or with the formula maker, as a condition its suppliers must meet before their powder is used?

Cost and volume. How many tankers a day does a dryer serving infant formula receive, and what would testing each one cost against what one outbreak costs?

How to weigh in

Send comments to me at bmarler@marlerclark.com, by Friday, October 30, 2026. If you work at a dryer, a formula plant or a testing lab, tell me so; that experience is exactly what these questions need. With your permission, I may quote you, with or without your name, in the petition docket or in a follow-up post. FDA has said, in its July 13 letter, that it wants to work with industry on best practices. Here is a place to start.