Child-resistant packaging is defined by a test rather than by a design. Understanding what the test actually measures explains why such packaging is never described as childproof.
The standard is behavioural, not mechanical
A closure qualifies by being given to panels of young children who are allowed a set period to open it, followed by a second period after a demonstration.
A package passes if only a small minority of the children manage it within the time. There is no engineering specification for torque or geometry that a manufacturer can simply meet.
This is why closures vary so widely in mechanism. Push-and-turn, squeeze-and-turn and aligned-arrow designs all pass the same behavioural threshold by different means.
Adults have to pass a test too
The same standard requires that older adults can open and properly reclose the package within a time limit. A closure that defeats children and also defeats the patient fails.
That second requirement is the binding constraint. Any design tight enough to be genuinely impenetrable to a determined child tends to fail the adult panel.
The standard therefore encodes a trade-off rather than an absolute. It is aiming at the best achievable balance, not at a sealed container.
What it is actually buying is time
The purpose of the delay is to keep a child occupied long enough for an adult to notice, intervene or arrive. Prevention here is a function of supervision reaching the child first.
A child left alone with a child-resistant container for a long period is a different scenario from the one the test models. The protection is not designed to hold indefinitely.
This is the reason storage guidance sits alongside packaging guidance rather than being replaced by it. The closure buys minutes; the cupboard is what actually restricts access.
Reclosure is where the protection is lost
Most closures only resist when properly reclosed. A cap resting on the thread, or pressed down without the turn engaged, provides no resistance at all.
Adults with dexterity difficulties sometimes leave caps loose deliberately, which is a reasonable personal adaptation and a household risk where children visit.
Repackaging into pill organisers removes the closure entirely, along with the labelling. Weekly organisers are common in households where grandchildren visit, and they are not child-resistant in any respect.
The categories covered are narrower than assumed
Requirements apply to defined categories of medicines and hazardous household chemicals, and the exact list varies by jurisdiction and changes over time.
Many substances that cause harm sit outside those categories entirely, including cosmetics, some cleaning refills, laundry capsules in certain formats and nicotine liquids in some markets.
If a child may have swallowed something, the immediate step is contact with a poison centre or emergency service rather than assessment at home. Packaging is a delay mechanism and nothing more.