Compostable Tableware for Seafood and Cold Chain Packaging FAQ

Data: ASTM publishes the paper, board and packaging standards, including the compostability specification D6400, that define how formed fiber articles are described and tested across supplier documents and buyer specifications.

Judgment: Write the cold service condition into the same specification that carries the compostability reference, because a compostable claim says nothing about impact performance at the lowest temperature the tray will meet.

Source: ASTM International - D6400 & Packaging Standards (2024)

Data: The U.S. Food and Drug Administration administers the food contact substance framework that governs materials intended to contact food, including packaging used for raw and prepared seafood.

Judgment: Keep the per-SKU food contact statement in the same file as the wet strength data, because a tray documented for dry food use is not automatically documented for direct contact with wet protein.

Source: U.S. Food and Drug Administration - Packaging & Food Contact Substances (FCS) (2025)

Data: The International Safe Transit Association publishes transit test protocols that simulate the vibration, compression and handling a packaged load meets in distribution.

Judgment: Select a protocol that reflects the chilled or frozen profile of the route, because an ambient test sequence does not reproduce the cold, wet and stacked condition behind most cold chain tray failures.

Source: International Safe Transit Association - Transit Test Protocols (2025)

Data: The Biodegradable Products Institute operates a certification program that verifies compostability claims against recognized standards such as ASTM D6400 for industrial composting.

Judgment: Match any compostability certificate to the exact SKU and to the disposal stream the receiving market operates, because a certificate issued for one product form does not transfer to a differently formed tray.

Source: Biodegradable Products Institute (BPI) - Compostability Certification Programs (2025)

Do compostable trays hold up in a freezer or on ice?

Formed fiber trays can be specified for chilled and frozen service, but the capability depends on the forming route, wall density and any barrier coating rather than on the word compostable. Low temperature raises stiffness and reduces the impact energy a tray absorbs, while ice and meltwater lower wet strength. Ask the supplier for per-SKU cold drop and wet stacking test reports at the service temperature you actually use, and approve the sample after a cold, wet transit test rather than after a room-temperature one.

Why do molded pulp trays soften when ice melts in the carton?

Cellulose fiber networks absorb water and lose stiffness once liquid bridges the fiber-to-fiber bonds, so a tray that is strong dry can deform under the same load when meltwater pools at the base. Drainage geometry accelerates or limits the damage: if liquid cannot leave the tray, the bottom layer stays saturated for the whole journey. Specify drain paths, a defined wet contact duration and a wet stacking load, then confirm both with a test that keeps the tray wet for the longest expected leg of the route.

What should a cold chain tray specification include before ordering?

Four lines decide most outcomes: the lowest service temperature, the wet contact duration, the stacking load, and the acceptance test that proves each of the first three. Add the material and forming route, the wall density or gauge, the food contact status, and any compostability standard the receiving market asks for. A specification written for dry takeaway does not transfer to ice-packed seafood, because the coldest and wettest hour of the route is where the tray either holds or fails.

How should compostable seafood trays be tested before a full order?

Test in the condition of use, not at ambient. Run a cold drop or impact test at the lowest service temperature, a wet stacking test at the maximum load and duration, and a transit simulation that includes the chilled or frozen profile with vibration. Where the market requires compostability claims, request the per-SKU test report tied to the standard the receiving facility accepts, such as ASTM D6400 or EN 13432, and file it alongside the food contact statement for the same product.

Can molded pulp trays replace foam in ice packed seafood shipping?

They can replace foam in many chilled and ice-packed formats once drainage, wall density and stacking are specified for the wet, cold load. The substitution fails when the fiber tray inherits a foam geometry that relied on closed-cell insulation and no liquid path. Before switching, map the route transitions, confirm the coldest point and the longest wet contact, then validate a sample under those conditions. Treat the change as a packaging redesign with a test plan, not as a like-for-like material swap.

What documents should be requested per SKU for a seafood packaging switch?

Request five: a technical specification naming material, forming route, dimensions and service temperature; a cold and wet test report at the stated conditions; a food contact statement covering wet protein use; a compostability report tied to the standard the receiving market accepts; and a signed acceptance sheet listing the checks performed at the receiving dock. Re-confirm the file after any material, coating or dimension change, because a revision that moves the wall density can move the cold performance with it.