Labels loose in the freezer: you take a sample out of the -80°C freezer and the label is lying loose at the bottom of the box. Or worse: it’s nowhere to be found. For a lab, this isn’t just an annoying detail; it can mean that a sample can no longer be identified, that a study loses a data point, or that you waste hours on relabeling and verification.
Labels that come loose in the freezer are one of the most common and most underestimated problems in laboratories that use cryogenic storage, (ultra)low-temperature freezers, or liquid nitrogen. The good news: there’s almost always an explanation for this, and therefore, it can be prevented.
The 3 main causes of labels peeling off in the freezer
- Condensation and ice formation between the label and the surface
This is by far the most common cause. As soon as a tube, vial, or bottle is removed from (or placed into) a cold environment, moisture forms on the surface. If you apply a label at that moment, the adhesive does not bond to the tube but to a thin layer of condensation or ice. As long as that layer remains intact, the label appears to be secure, but as soon as it melts, shifts, or the tube is handled, the label loses its grip and comes loose. Sometimes immediately, sometimes only after a few freeze-thaw cycles. The same problem arises when relabeling material that’s already frozen: you don’t want to break the cold chain by thawing it first, but a label that isn’t designed to adhere to a frozen or damp surface simply won’t stick. - The wrong type of adhesive for low temperatures
Standard adhesives are designed to work at room temperature. At low temperatures, they become stiff and brittle: they lose their adhesive strength just when you need it most. A label that works perfectly on a box in a warehouse may fail completely in a freezer at -20°C, let alone in liquid nitrogen at -196°C. There is no “one-size-fits-all” adhesive for cold applications. An adhesive suitable for a refrigerator is not necessarily suitable for cryogenic storage. The more extreme the conditions, the more specific the choice of adhesive and material must be. - Shrinkage and material stress due to temperature changes
Every material shrinks and expands in response to temperature fluctuations. The label, the adhesive, and the tube itself each do so at their own rate. During repeated freeze-thaw cycles, stress builds up between these layers. Eventually, this stress can cause the edge of the label to curl or the label to peel off entirely. This explains why a label that looks fine at first may still start to peel or curl after a few cycles in storage.
What a label must be able to do to stay in the freezer
A reliable freezer label combines three characteristics:
- Material that remains flexible at low temperatures (such as thin polyester or polypropylene) rather than becoming brittle and cracking.
- An adhesive specifically designed for cold applications, with sufficient bonding strength to adhere even to slightly damp or frozen surfaces.
- Sufficient contact surface, especially for small diameters such as cryovials and Eppendorf tubes. A self-laminating or wrap-around label that wraps around the tube provides significantly more grip than a small rectangular label.
This prevents labels from coming loose in the freezer.
- Make sure the surface is dry before you apply the label: wipe away any condensation or ice with a lint-free cloth. This is the most important and least expensive step, and it’s the one most often skipped in practice.
- Label at the correct temperature: Most labels need to be applied at a higher temperature to adhere properly. So be sure to check not only the label’s storage temperature, but also the recommended application temperature.
- Choose the material based on the most extreme conditions in your process: Will a sample go from room temperature to -80°C, then into a water bath, and possibly an autoclave? If so, the label must withstand all those steps, not just the freezer.
- Use self-laminating labels for small diameters: The smaller the tube, the less contact surface area.
- Press the label down firmly and evenly: Air bubbles or a loose corner are often the starting point for the label to peel off after a few cycles.
- Test before ordering a full batch: Testing adhesion, contrast, and scannability on your own samples takes very little time, but prevents you from purchasing a full stock of labels that ultimately won’t work in your process.
Which label is right for your application?
There isn’t just one type of freeze label. The right choice depends on your tube, temperature, and process:
- Do you work with vials, cryovials, bottles, or tubes in varying conditions? Check out our labels for vials, bottles, or tubes here
- Do you need to (re)label frozen samples without breaking the cold chain? Discover our labels for frozen tubes here
- Does your process involve cryogenic storage, autoclaving, and chemical cleaning? Check out the options here for labels designed for extreme conditions
- Do you need a non-standard size, core, or type of adhesive? We can accommodate that with our custom labels.
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