Most synthetic urine is good beyond 8 hours. For example, Quick Fix has a shelf life of 18 months and can be heated and cooled repeatedly. It does not require refrigeration or freezing during storage. It will not "ferment." Human urine will start to break down around the 8 hour mark and after several more hours, depending on the urine and conditions, ammonia will form and can be detected. Room temperature storage is one of the advantages of Quick Fix. Ok, now you are just splitting hairs because elevated levels of HCG can be present in pregnancy, prostate, and testicular cancer as well as a couple of other conditions. Bottom line is employers can't test for for HCG during a drug test or any other hormones or even genetic testing because it is illegal. Right off the top of my head I can't think of any point during employment where you can be forced to submit to hormone or genetic testing. I am going to get more into this in a minute. It is not the job of the lab tech to interpret the results, that is what the Medical Review Officer (MRO) is for, who is not a tech but a doctor with a medical degree. It will never get this far because it is illegal to perform hormone testing during a drug test. Period. Besides, most doctors I know would start with an ultrasound! HIPPA was enacted in 1996 and mainly deals with health care privacy. I am almost 100% certain that the laws that prevent employers from performing hormonal testing on employees is covered by another act and has been on the books much much longer. It isn't just a violation to do such testing, it is against the law. It doesn't have to do with the extra cost either. It is safe to use either gender urine as long as it is not dilute or dirty.