Two numbers, pulling against each other

Eighty-five percent, for children

Child-resistant effectiveness of not less than 85 percent without a demonstration. That is the headline number and it is the one people know. It is measured, not asserted, and the measurement is the next page.

Ninety percent, for senior adults

Senior adult use effectiveness of not less than 90 percent. This is the number almost nobody outside the industry knows, and it is arguably the harder one: the package must be openable, and properly resecurable, by nine in ten older adults.

Why the second number exists

A package so difficult that its owner cannot open it gets left open, decanted into something else, or never closed properly, and then it protects nobody. The senior requirement exists because the obvious way to pass the child test is to make the package impossible, and that makes things worse rather than better.

Resecuring is part of it

The senior test requires the package to be opened and, where appropriate, properly resecured. A closure that comes off easily and goes back on wrongly has failed, because a package that is not reclosed correctly is not child resistant the second time.

And it has to keep working

The standard says special packaging must continue to function for the number of openings and closings customary for its size and contents. A mechanism that works on the first use and wears out over a month of daily doses does not satisfy it.

Which is the whole design problem

Every mechanism in this category is an attempt to find an action an adult finds easy and a small child does not, that survives repetition. Push and turn, squeeze and turn, and line up and lift are all answers to the same question.

References