When using sample storage tubes, care must be taken with the types of plastics that they are composed of since they can contaminate the sample.
Extractables are chemical compounds that are able to be extracted from a primary container or type of component material and be absorbed by drugs or biological products and contaminate them (these are typically elastometric or plastic constituents).
Leachables are compounds that can leach into a drug or biological product through the closure system for the container. Leaching mainly occurs as a result of direct contact under normal usage conditions.
Both extractables and leachables can be present as a result of inferior manufacturing techniques or through a lack of process control when using additives or agents applied to raw materials. Leachables are typically present in a sample tube of inferior quality while extractables can only be present after gamma irradiation has failed to sterilize tubes produced in a non-sterile environment.