# AET for upstream manufacturing systems

**URL:** <https://knowledgeexchange.usp.org/t/aet-for-upstream-manufacturing-systems/97>\
**Category:** Extractables and Leachables\
**Tags:** analytical\
**Created:** [October 27, 2026, 11:12am UTC](https://knowledgeexchange.usp.org/t/aet-for-upstream-manufacturing-systems/97 "2026-10-27T11:12:26Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![gpreddy](https://avatars.discourse-cdn.com/v4/letter/g/c0e974/32.png) [@gpreddy](https://knowledgeexchange.usp.org/u/gpreddy)\
**Post date:** [October 27, 2026, 11:12am UTC](https://knowledgeexchange.usp.org/t/aet-for-upstream-manufacturing-systems/97/1 "2026-10-27T11:12:26Z")

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How should companies proceed when an AET cannot be reliably calculated for upstream manufacturing systems?