Certain medications and foods may cause a false positive result on a drug test. Not only do you need to take appropriate steps to ensure there are no traces of drugs in your system, but you also have to prevent a false positive from showing up on an EMIT test. The following foods and over-the-counter medications have been known to cause false positives on EMIT tests:
Dental products, such as Novocain or any product ending with -cain
Ibuprofen (and potentially any other pain reliever)
Hay fever remedies
It is extremely important to avoid consuming any of these products in the 48 hours prior to an EMIT screening, because even if you have taken the right steps to detox yourself from illicit drugs, these substances can trigger a false positive. This means your sample will be referred for further testing using gas chromatography-mass spectrometry (GC-MS).