There is a common misread of the food transportation rules that goes like this: "we use dry ice, so we're covered." Dry ice keeps the product cold, cold is the goal, therefore compliant. The FDA's Sanitary Transportation rule does not work that way. It is not primarily about how cold the product is. It is about who is responsible for defining the temperature control, whether that definition was agreed in writing, and whether anyone can prove it happened.

If you ship perishable food, especially direct-to-consumer meal kits, seafood, or specialty frozen product, the FSMA Sanitary Transportation of Human and Animal Food rule sets the frame. Dry ice is a perfectly valid tool inside that frame. The compliance work is in the paperwork and the process around it, not the ice.

What the rule is, in one paragraph

The Sanitary Transportation of Human and Animal Food (STF) rule, issued under the FDA Food Safety Modernization Act (FSMA), applies to shippers, loaders, carriers, and receivers who transport food by motor or rail vehicle in or into the United States. Its purpose is to prevent practices during transportation that create food safety risks, and temperature control for foods that need it is one of those practices. The rule deliberately uses a flexible, outcome-based approach rather than dictating specific equipment, which is what makes dry ice, mechanical refrigeration, gel packs, and other methods all acceptable, provided the outcome is controlled and documented.

The shift that matters: the shipper owns the spec

Here is the part that trips up food businesses. Under the rule, the shipper holds primary responsibility for determining the transportation conditions necessary to keep food safe, including temperature. You cannot hand a box to a courier and assume they will figure out the cold chain. You specify it.

That responsibility can be assigned to another party by written agreement, but it does not evaporate. If you are the shipper, the rule expects you to have decided what temperature control the product requires and to have communicated it. "We threw in some dry ice" is not a specified condition. "This product ships frozen, held at or below a defined temperature, using a validated dry ice pack-out for the transit duration" is.

The four things a dry ice program needs under the rule

Translating the rule into what a dry ice shipper actually maintains:

1. A defined temperature requirement for the product. You decide and document the temperature the food must be kept at in transit, based on food safety, not guesswork. Frozen product has a target; refrigerated product has a range.

2. A written agreement covering temperature control. The rule contemplates written agreements between shippers and carriers specifying the temperature control responsibilities. When you ship with dry ice via a carrier, the arrangement, who is responsible for what, needs to be established in writing, not by assumption.

3. Adequate pre-shipment preparation. Before loading temperature-sensitive food, the party loading it must confirm the transport is adequately prepared. For dry ice, that means the pack-out, the container, and the dry ice charge are sized to hold the product at its required temperature for the whole transit, including foreseeable delays.

4. Records that show it happened. The rule replaced a rigid device-mandate with a more flexible monitoring approach that shipper and carrier can agree on, but the expectation of demonstrable control remains. You need records: your pack-out specification, the agreement, and whatever monitoring or verification method you chose. If you cannot show it, you cannot prove compliance.

Why "we use dry ice" is not the same as "we're compliant"

Dry ice at −78.5 °C will absolutely keep frozen food frozen. That is not in question. The gap is that compliance under the rule is about the system, not the substance. Three specific failure modes:

No defined target. If nobody wrote down what temperature the product must stay at, there is no standard to have met. Dry ice was present, but present is not a spec.

A pack-out sized by habit, not for the lane. Dry ice sublimates continuously. A charge that works for a two-day lane fails on a four-day one. A pack-out that is not sized to the actual transit time, with a margin for delay, can arrive with the product thawed and the shipper still saying "but we used dry ice." Sublimation math is part of compliance, not separate from it.

No records. If the process is real but undocumented, an FDA investigator or a customer's food safety auditor has nothing to review. Under an outcome-based rule, the records are the evidence of the outcome.

The dry ice sizing question is a food safety question

Because the rule is outcome-based, the technical work of sizing the dry ice charge is not a logistics detail off to the side. It is how you meet the standard. The variables are the same ones that govern any dry ice pack-out: container insulation (EPS versus VIP), the transit time including realistic delay, the ambient temperature the box will see (summer changes the answer), the payload mass, and the form of dry ice. Getting this right, and documenting the pack-out you validated, is simultaneously good logistics and the substance of compliance.

A supplier matters here in a specific way. Consistent, documented dry ice product, known form and nominal density delivered reliably, lets a shipper validate a pack-out once and trust that the next shipment behaves the same. Variable product undermines the validation the rule effectively asks you to stand behind.

A short compliance checklist for dry ice food shippers

• Define the required transport temperature for each product, based on food safety.

• Establish written agreements with carriers covering temperature responsibility.

• Validate a pack-out sized to the actual lane, transit time plus delay margin, ambient, payload, container.

• Confirm preparation before each load: right container, right dry ice charge.

• Keep records: the spec, the agreement, the pack-out, the monitoring method.

• Re-check in summer, when higher ambient temperatures raise sublimation and shrink your margin.

Questions we get asked

Does FSMA require a temperature logger in every food box? No. The rule moved away from a rigid device mandate to a flexible approach the shipper and carrier agree on. You still need to demonstrate control, so many shippers use monitoring, but the specific mechanism is a choice, not a fixed requirement.

Who is responsible if the product thaws in transit, the shipper or the carrier? The shipper holds primary responsibility for specifying the conditions, and responsibilities can be assigned by written agreement. That written agreement is exactly what determines accountability, which is why the rule emphasizes it.

Is dry ice an approved refrigerant under the rule? The rule is outcome-based and does not prescribe a refrigerant. Dry ice is a valid method as long as it achieves and documents the required temperature control.

Does the rule apply to a small direct-to-consumer food business? There are exemptions, including for very small businesses by revenue, so check your status against the rule. But the food safety logic, and your customers' expectations, apply regardless of whether the rule technically binds you.

The summary, on one line

FSMA does not ask whether you used dry ice; it asks whether you defined the required temperature, agreed responsibility in writing, sized the pack-out to the lane, and kept records to prove it, and dry ice is a fully valid tool once that system is in place.

This post is general information, not legal or regulatory advice; confirm your obligations under the FSMA Sanitary Transportation rule against the current FDA text and your own counsel. Cryo Life Solutions supplies consistent, documented pelletized and slab dry ice to food and specialty cold chain shippers across the Northeast US, supporting repeatable, validated pack-outs. Delivery across MA, NH, RI, CT, NY, NJ, and PA. Call 603-802-6650 or email info@cryolifesolutions.com.

Related reading: More cold chain field notes from Cryo Life Solutions