In practice, 'peelability' is a relative term; actual peelability is determined by the force that must be exerted in order to remove a self-adhesive label and the corresponding requirements (e.g. it must be possible to remove the label without leaving residues behind).
In order to determine whether a particular label is peelable or designed for permanent attachment, first stick 2/3 of the label to a smooth surface (such as that of a table top) and then pull suddenly on it to remove it again. If a removable adhesive has been used, there will be almost no sound when the label comes off. A loud, sharp and abrasive noise will be produced if a permanent adhesive has been used. Although it is relatively easy to remove a label with a permanent adhesive soon after attachment, this does not mean that this is necessarily a peelable label. Several minutes or even hours are required until a permanent adhesive will have achieved most of its bonding strength.