A single passing lab report at launch tells you nothing about the batch on shelves eight months later.
A certification based on one initial test, run once at launch, makes an implicit and unjustified claim: that every subsequent production batch performs identically to the sample that was tested. Manufacturing variability, ingredient sourcing changes, and equipment wear all mean that assumption doesn't hold indefinitely.
That's why the MPFREE Standard requires ongoing batch testing — every production lot tested against the primary screening method before its QR code or seal is activated in the public registry — plus unannounced surveillance audits at least annually for as long as a certification stays active. A batch that fails its threshold suspends immediately, and that suspension is visible in the product's public certification history, not silently absorbed.
Chain of custody is the record that makes this enforceable: witnessed sampling, a documented custody trail from collection through lab report, and a hash-chained event log (see the certification-and-standards articles) that shows exactly when a certification was issued, tested again, suspended, or revoked — and why.