CGA M-12 provides guidance on how a food or medical gas manufacturer shall evaluate OOS test results. Although this publication is based on FDA's October 2006 Guidance for Industry Investigating Out-of-Specification (OOS) Test Results for Pharmaceutical Production, CGA M-12 also applies to device and food gas OOS test results obtained during testing of these products.

OOS test results include all test results that fall outside the specifications or acceptance criteria of the official compendia or that do not satisfy the manufacturer's definition of acceptance. An OOS condition within a food or medical gas production facility is generally considered any failure of a batch, a lot, or finished product. Provided the plant's automated or manual systems are qualified, operated as designed, and do not allow out-of-specification product to be produced into product storage, OOS investigations are not required for process plant upsets.

This publication applies to traditional batch test release and not to Process Analytical Technology models, since they use process controls and in-process data as the release mechanism. It also applies to chemistry-based laboratory testing of food and medical gases as well as contract firms that perform testing of food or medical gases.