Have you ever wondered why your 96 hours qualified 15-25 solution goes out of spec after two days? Historically, water-based 15-25 solutions have been qualified differently than 2-8 solutions. This is because they are not designed to control the temperature between 15-25 degrees; there is very little temperature control inside a water-based 15-25 solution. The qualification process has been adapted to reflect this. If you take the time to compare the qualification reports of a 2-8 and 15-25 solution for the same payload and duration, say 96 hours, you will probably find that a different temperature profile was used in the qualification process. Yet if you have two shipments, one 2-8 and one 15-25 going to the same destination on the same day, you can be sure they will experience the same ambient temperatures, so why have they been qualified to different temperatures profiles?