Four Papers to Ask a Gel Pack Supplier For, and What Each Proves

Nine days. That is how long a container of gel packs sat at a port in Mombasa while a buyer tried to obtain a food-contact declaration that the factory had never issued. The packs were fine. The paperwork did not exist, and no amount of product quality replaces a document that a compliance officer is waiting for.

Most buyers ask for a stack of certificates and never read them. A shorter list, read properly, does more work. Here are the four that matter, in the order they resolve questions.

One: the batch certificate with the right test on it

A certificate of analysis should carry the batch number, the production date, and the measured values for the properties that predict field performance. For a gel pack, that means absorbency under load at the service temperature, gel strength or viscosity at fill, and drainage after a defined number of freeze-thaw cycles.

What it usually carries instead is free-swell absorbency in deionised water at 25 °C, which is the number that predicts almost nothing about a pack sitting at -18 °C under a stack of cartons. Ask for absorbency under load and for a cycle drainage figure. If the supplier cannot produce either, ask how they qualify a batch at all — the answer tells you more than the certificate.

Two: the food-contact declaration

If the pack may contact food — and on a seafood or meat lane it will — the buyer needs a declaration that the finished article complies with the food-contact rules of the destination market, covering the film, the gel and the ink. This is a statement about the finished pack, not about the polymer pellet, and a resin supplier’s letter does not substitute for it.

Ask for it per market, because the requirements differ and a generic “food grade” letter is refused by most serious importers. Keep it with the shipment file and check the expiry date, since these declarations are usually issued for a limited period.

Three: the seal and drop test report

This is the document that predicts leakage, and it is the one buyers ask for least. What you want is a report that shows seal strength in newtons per 15 mm across the seal, a burst or creep test at the service temperature, and a drop test from a defined height with the box loaded to its real mass.

The detail that matters is the temperature. A seal that holds 28 N at 20 °C may hold 12 N at -18 °C, and a report run only at room temperature is not evidence for a frozen lane. Ask for the test temperature to be stated on the report. If it is not there, the report is decoration.

Four: the transport classification statement

Gel packs are generally not dangerous goods, but the buyer still needs a written statement from the supplier confirming the classification of the article as supplied, plus the composition in enough detail for the forwarder to make their own call. This is what lets your freight agent answer an airline query in an hour instead of a week.

The counter-intuitive point about this list: the safety data sheet, which almost every buyer requests first, is the least useful document for a sealed gel pack. It describes the material for handling and emergency response, not the article’s performance or its compliance as packaging. Ask for it, keep it, and do not mistake it for any of the four above.

How to ask

Put the four documents in the purchase order as deliverables with the first production batch, not as a request after the shipment. Name the test methods and the temperatures. Then keep a copy in the lane file so the next shipment does not restart the conversation.

If a supplier pushes back on the cycle drainage figure, that is useful information on its own. The SAP powder range lists which grades carry a drainage figure at 20 cycles, which is a reasonable place to start the comparison.