Should I keep samples of in-service lubricating grease?

Samples of in-service lubricating greases should be tested promptly to obtain current status of lubricants and machinery.  If there is a delay in shipping samples, they should not be exposed to direct sunlight, elevated temperature, or moisture.  Laboratories typically dispose of grease samples after they test them.  If in-service grease has been collected during relubrication, but is not to be tested, then it should be disposed of promptly according to all applicable regulations.