Getting started with proper testing strategies
Before single-use equipment became common in biopharmaceutical production, L&Es were mainly considered for packaging. Today, most biomanufacturers use simple biological reactivity tests to evaluate the risk of L&E impurities. This is insufficient. Modern systems require comprehensive and meaningful analytics. 
“Searching for leachables without a prior extractable study is like looking for a needle in a haystack”, is how Desmond Hunt, the principal scientific liaison at the US Pharmacopeial Convention, was recently cited in an issues paper.  This quote sums up the challenges and requirements of L&E testing.
A proper testing strategy should be based on extractable data, as this provides the needed primary information on potentially leachable chemical entities. Compared to determining leachables it is quite fast and easy to search for extractables for plastic components used in a biopharmaceutical production process.