The reason that was put in to Q7A is that you should be using materials that will cause the least
amount of harm if a small amount gets into your batch. If, however, you have catastrophic seal
failure and a large amount of lubricant gets into the batch, you really should investigate this as a
deviation and determine its impact on the quality of the API or intermediate. Yes, that does mean
that small amounts may get into your batch, but it is not intended to imply that you don’t
investigate failures or process deviations.
