Being subjected to random drug test due to my employment, I purchased a Ultra Clean urine kit. I always kept it close at hand. But a couple years passed with no test. I knew I need to purchase fresher stock, I was not aware of the expiration date but it was getting old. I kept postponing and forgetting to order more. Then it came, the drug testing man was there bright and early (4:30am) one morning. Having no other choice I warmed the bottle and strapped it along with the heat pad to my leg and hope to hell it worked. Unless there is a documented need our test are not observed, but the location selected to use for collecting samples was not very private. I some how managed to fill the cup to the minimum mark, then proceeded to spill half of it. Guess its a good thing I had the 4oz kit. I replaced what I had spelt, check the temp and delivered my sample to the collector. And to my relief the collected done his checks then split the sample into 2 containers for me to initial. Our policy states that all samples should undergo validation testing, then an immunoassay test. Then GC/MS testing for confirmation if needed. This means it would be a few days before the results were in. The wait was on. After about a week with no news, i happen to find the remnants of the box my Ultra Clean was in, as the box had become worn and tattered over the years. I could still read some of the printing on the box. Or at least I could read the part that stated 3 year shelf life. I would not recommend pushing the 3 year shelf life like I did. I'll have to say that the product worked as advertised. I would recommend Ultra Clear to anyone who finds their self in the need for a good synthetic urine.