I just wanted to let people know that QF 6.2 does have an expiration date. I got popped for a 5 panel DOT random, I had 30 munits plus drive time to get to the test facility. I thought for sure I was in the clear with my QF. I called to verify the batch and the lady told me that it had expired this month (the test was at the beginning of the month) I was a little shocked considering I thought it had a one year shelf life and I had just bought it from the qf website around June. She told me that the creatine levels drop after a certain amount of time. I had no choice but to use it and I ended up getting a call from the MRO saying my test was invalid and I had to have a wittnessed re test. Luckily I was not that dirty and was able to mask with QCarbo for the re test. If you have a batch from around June, I suggest you call and verify before you run into the same situation that I did. Also I do not have the batch number, I must have tossed the paper because I cant find it anywhere.