Tamper Evidence: What the Feature Must Prove and What It Costs

Tamper evidence is a design feature that shows whether a pack has been opened before purchase. It is a legal requirement in some markets and a marketing reassurance in others, and it has to be obvious at a glance, impossible to restore, and cheap enough that it does not change the price.

1. The three options

A shrink band around the closure, a break tab on the cap, and a foil or induction seal under the cap. Each proves a different thing: the band proves the cap was not opened, the tab proves the cap was not twisted, the foil proves the bottle was not filled or refilled.

2. Shrink band

A PVC or PET shrink band is applied after filling and must be cut to open. It is cheap and visually obvious. It is also a second material on the pack and a recycling contaminant, and PVC bands are increasingly restricted.

3. Break tab

A cap with a break tab that must be snapped before the cap turns is the most common solution for a bottle. It is mono-material with the cap and requires no additional component. The tab must break visibly and cannot be reattached, which is the whole point.

4. Foil seal

An induction seal under the cap is used for jars and for products where the fill integrity matters. It proves the jar was sealed at filling. A jar with a foil seal and no shrink band is adequately protected in most markets.

5. The failure mode

Tamper evidence fails when the feature can be restored or when it does not visibly change. A shrink band that can be re-shrunk, or a tab that looks identical after breaking, is not tamper evidence. The design must be tested by opening and attempting to restore.

6. Regulatory requirement

In the EU, cosmetic products must be protected against tampering during distribution, and the pack should show evidence if it has been interfered with. In the US, tamper-evident packaging is required for some product categories and recommended for others. The requirement depends on the market.

7. Cost

A break-tab cap costs almost nothing extra because it is part of the mould. A shrink band adds a component and a machine step, and typically costs a cent or two per unit. A foil seal adds a step and a component. The cheap options are the ones integrated into the closure.

8. Customer experience

A tamper feature that is hard to open generates complaints, and the complaint is usually about dexterity rather than about safety. A tab that requires a tool, or a band that must be cut with scissors, is a design failure. Test with older users.

9. Recycling

A break-tab cap is mono-material and recyclable with the bottle. A shrink band is a second material and must be removed. A foil seal on a PP jar is a mixed-material pack. A brand with a recyclability claim should prefer the integrated feature.

10. E-commerce

Products shipped direct have a higher tamper risk than products sold through retail, because the parcel passes through more hands. For direct-to-consumer, a tamper feature plus a sealed outer carton is the standard combination. The carton is the second layer of evidence.

11. Where it fits

Tamper features run across the cream range; the closure detail continues in the closure entry.