The pen leaked
Updated
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What the exemption requires
That the methacrylic acid is contained by the absorbent material so that no free liquid is within the device, and that under any reasonably foreseeable conditions of use it will emerge only through the tip.
So device quality is compliance
A pen that weeps at the tip, floods when warm, or has liquid sloshing behind the absorbent core is not the device the exemption describes. That makes the component specification a regulatory matter rather than a quality one.
Reasonably foreseeable use includes misuse
The phrase is in the rule. A pen squeezed, shaken, carried in a warm bag or left tip-down is being used foreseeably, and the condition has to hold in all of that.
Which argues for testing in those conditions
Filled, capped, left tip-down, left warm, carried in a bag for a week. The exemption is only as good as the device, and the device only reveals itself in use.
The absorbent is the component to specify
It has to hold the acid rather than merely be wetted by it, and it has to keep doing so over the product’s life. A core that degrades in the acid releases free liquid, which is precisely the failure.
And the alternative is the tested-packaging route
If the device cannot hold the condition reliably, the honest answer is a bottle with child-resistant packaging meeting 1700.15, not a pen that mostly works. Those are the two routes and there is no third.
Keep retained units and open them later
Filled, dated, stored as stock is stored, and examined at intervals for free liquid. It costs a few units and it is the only evidence that speaks to the exemption as written.