(Shutterstock)Soap has been positively identified as the date-rape drug, GHB, candy has been confused for meth, and mints have been allegedly mistaken for crack cocaine.

To an innocent person suspected of drug possession, simple mistakes in drug-identification tests taken by law enforcement in the field have caused more complex problems.

The analyses have drawn scrutiny, after false positives were recorded in a series of cases reported by media outlets across the country. But, field drug testing continues to be used by law enforcement nationwide.

The latest gamut of tests analyzing the controversial tests was a series of lab experiments conducted by Florida TV station Fox 13 Tampa.

The videotaped tests showed that mundane items found in supermarkets, including coffee, aspirin, chocolate and oregano, can come up positive for narcotics using the most common tests available to law enforcement. Even Mucinex DM, an over-the-counter cough medication, came up positive for heroin and morphine, they said.

The tests are single pouches that retail for between $10 and $20, and are specific to testing for particular substances, according to the sites of the manufacturers.

The American Civil Liberties Union in Florida has announced they are seeking to investigate how widespread the “presumptive” drug tests have been used in the Sunshine State.

But it’s not the first time that field tests have drawn scrutiny.

A 2008 report entitled “False Positive Equal False Justice” was commissioned by the defense-attorney organization California Attorneys for Criminal Justice. The authors, who included former FBI chief scientist and narcotics officer Dr. Frederic Whitehurst, found a series of instances where false positives resulted in arrests or criminal charges that were only negated after further lab testing. They included a Pennsylvania college student who was carrying condoms filled with flour, which were misidentified as carrying cocaine in 2003; and also Don Bolles, a drummer for the punk band The Germs, who was detained for possessing the date-rape drug GHB – but which turned out to be soap. A couple was also briefly arrested when their chocolate turned up a false positive for hashish.

All three cases were eventually dropped.

The Marshall Project reported that cheap tests can produce errors, and cited a series of criminal cases which were dropped after initial tests were invalidated by full laboratory analysis.

Few studies of the field kits used by law enforcement have been conducted, according to a search of the government database PubMed. But in 2007 a group of researchers tested the Drink Safe test, which is intended for consumers to test beverages for date-rape drugs. The study, published in the Journal of Analytical Toxicology, concluded the results had a tendency to be inaccurate outside a laboratory setting.

The two manufacturers responsible for the pouches tested in the Florida TV report, Sirchie, and the Safariland Group, could not be reached.