You may be a saint on Earth, no drugs, no cigarettes, no alcohol, no women, and they can still blame you for haunting the rave clubs and being a feared rapist. Because when your urine is kept for longer than 6 months in a refrigerator, it can accumulate GHB, an illegal drug.

FBI researchers at a laboratory in Quantico, Virginia, discovered that urine samples spontaneously synthesize significant amounts of the GHB or other chemicals, leading to false positive result from the most stringent test employed by forensic labs, throwing into jail innocent people for exposure to the illicit chemical.

GHB (gamma-Hydroxybutyric acid), also named liquid ecstasy, is made from gamma butyrolactone, a solvent employed to degrease engine parts or clear plugged drains, and which occurs naturally in the central nervous system.

It has turned into a popular rave drug and it is also consumed by rapists as a means to knock people out before sexually assaulting them. GHB has neither color nor scent, being easy to slip into an unsuspecting victim's drink.

The research team signals that the urine should be kept in a refrigerated or frozen condition and analyzed as quickly as possible to diminish false evidence. GHB analyses are relatively infrequent requests in many laboratories and some specimens are likely to be preserved for long periods of time before being analyzed.

Still, the researchers do not know how the GHB accumulates in the urine.

The team collected urine specimens from 31 people who had never used the drug. The samples were analyzed after seven days, 60 days, and 189 days with a gas chromatography mass spectrometer, which tracked down the nature and quantity of various chemicals (drugs and poisons) in blood, urine, and other liquids. In most of the samples, the GHB level increased significantly after six months of storage in a refrigerator.