Distinguish Material Expiry from a Retest or Extension Decision

An expiry date, a suggested retest date, and a supplier-authorized extension are different records. Keep their meanings distinct for solder paste, adhesives, coatings, and other assembly materials. A passing quick check does not automatically establish every property required by the production process.

Start with the product-specific storage definition

Indium’s Indium6.2 data sheet ties shelf-life information to specified storage conditions and includes container-opening guidance. Its conditions belong to that material. Do not apply them to another paste or use a chemical’s unopened shelf life as its permitted working time after opening.

Identify the product code, formulation, lot, original label, storage record, opening history, and any excursions. Determine whether the material has been transferred or mixed. If its actual history is unknown, a label showing a future date may still be insufficient evidence for release.

State what a retest would establish

• Identify the properties relevant to the intended process and product.
• Agree the method, sample selection, and acceptance criteria.
• Confirm who is authorized to evaluate or extend the material’s use.
• Define the quantity, containers, and time period covered by the decision.
• Retain the original date information alongside the new disposition.

A viscosity result may support one aspect of dispensing or printing behavior, while leaving other properties unexamined. Use the viscosity-method review if that measurement is part of the plan. The test should answer the disposition question, not simply produce a reassuring number.

Prevent an extension from spreading

For example, a supplier may approve a particular unopened container after reviewing storage evidence. That approval does not necessarily cover an opened container from the same lot, a different storage location, or material already recovered from the stencil. Preserve the stated scope and maintain separate statuses for those quantities.

Keep the container-time history intact when applying a revised internal label. Do not replace the original expiry information in a way that hides the reason for the extension or its authorizing record.

If material is reserved for an engineering experiment, label it accordingly and prevent its return to unrestricted production stock. Close the decision as use within the documented scope, continued hold, return, or disposal under the local material-control procedure. The useful outcome is a bounded, evidence-backed disposition rather than a new date typed onto a label.