Clic-Loc is a two-component product: it has an outer cap with swing tabs, which - when pushed down and twisted - drives the inner, threaded cap, allowing the bottle to be opened. It emits an audible click if the top is twisted without first being pushed in - warning parents that their child is raiding the paracetamol.
The need to push and twist simultaneously is crucial to the device's effectiveness.
Other variants include squeeze and twist (often seen on mouthwash) and lining up arrows (used on pill bottles).
Because Clic-Loc has two components, it is more expensive to produce than alternative methods. But it has a vital advantage; while being difficult for children to open, it is relatively easy for elderly people to manage. An arthritic person, for example, can use the heel of the hand to press down while twisting the top.
Clic-Loc caps are made from PP (for the inner closure) and PE for the outer closure.
Recent developments in child-resistant closures include Sanner's packaging with a new 'press-in, pull-up' mechanism so, as well as being childproof, it is easy to open by the elderly. And Paragon Packaging has introduced a child-resistant cap on its medo PAC range of glass bottles, which is traceable. The closures and bottles are invisibly UV inkjet coded at the point of capping so that each component can be fully traced should any quality issues arise or more serious incidents occur, such as a child poisoning.