3.2 False positives: No laboratory process is completely free from error. The GC/MS test is virtually error free, but the EMIT is far from accurate. There are some false positives you should avoid if you're getting an EMIT test. Take this seriously; false positives run high. If you know that there will be a GC/MS confirmation test, you can disregard this section. It would be too lengthy to list all of the false positives here. Jeff Nightbyrd's "Conquering the Urine Tests" pamphlet lists a majority of the false positives in detail. (If you are clean, want to get back at the testing industry for conducting these absurd tests, and know that there will be a confirmation test, you could consume several false positives. This would force labs to pay for the high priced GC/MS test, eventually drive up test expenses. You will still pass the test as long as you didn't use any true positives.)