It would help to know to which materials you refer.
If you refer to Liquid for Fluorescent Penetrant Inspection, contamination is not related to new material but to continued use. If this is the case, the manufacturer certificate would not be expected to certify absence of contamination. See:
It used to be pretty common for a statement such as this to be on the bottom of steel MTRs.
Once upon a time there was a considerable amount of contaminated rebar in the pipeline.Seems someone had done some remelt of old reactor parts. Story is that most of this was buried just across the border from ElPaso.
If you ask the mill they will include the statement you seek.
Steel from 9/11 disaster arrived in India. Rumours were strong that they were contaminated and hence steels from these mills were offered at a discount.
I saw a set of material certificates of an ASTM A-516-70 plates in our Mechanical Catalogue with that kind of certificate and I am not familiar with it.
