Tamper evidence and induction seals
Updated
On this page5
Another category where the legal answer and the commercial answer differ.
Not required, and expected
There is no general tamper-evident packaging requirement for household cleaning products.
A child-resistant closure may be required, and that is a different thing with a different purpose: it is about a child getting in, not about showing whether an adult already did.
What drives tamper evidence here is retail and distribution, plus the practical fact that a sealed bottle does not leak in a parcel.
Induction seals
A foil disc heat-sealed to the bottle neck under the cap. The standard answer, and it does three jobs: it shows the bottle is unopened, it stops leaks in transit, and it slows evaporation and fragrance loss.
It needs an induction sealer and a liner compatible with your formula and your resin.
It is also the thing that makes a mail-order liquid business viable, because an uninduction-sealed cap under a courier is a leak waiting to happen.
Bands and shrink sleeves
A shrink band over the closure seam: cheap, visible, and quick with a heat gun.
A full sleeve can be the label as well, which solves the label adhesion problem at the same time and costs more.
Neither seals the bottle, so for shipping an induction seal does work a band does not.
Where it matters
Most in mail order, where it is really leak protection.
Next in retail, where a buyer may require it.
Least at a market, where you hand the bottle over.
And it matters more than usual for anything hazardous, because a customer needs to know a bottle has not been opened, decanted or refilled with something else.