Drug Test Standards and Accuracy
It is important not to pay too much attention to statistics as they pertain to drug testing standards. Those who oppose drug testing provide numbers indicating a high level of false positives, while those who favor drug testing provide numbers indicating high levels of accuracy. The fact is accuracy varies widely from lab to lab. Generally speaking, NIDA labs are accurate. Clinton writes:
“NIDA (The National Institute of Drug Abuse) is the government organization responsible for regulating the drug-testing industry. The vast majority of urine drug screens done these days conform to NIDA specs, and ALL testing associated with the government (department of transportation, etc.) complies with the NIDA standard. It is NIDA that decides what the "safe" cutoffs are to avoid false positives.”
Despite what you might hear on the net, urinalysis - if done correctly - is a very accurate scientific procedure. There are no labs that simply report the results of the initial EMIT screening without confirming the sample on GC/MS. Labs actually want you to test negative, because then they only have to run an EMIT test on your urine (a few cents). If you test positive, they must then confirm the positive result on GC/MS, which is considerably more expensive.
CAP (College of American Pathologists) also certifies laboratories the way NIDA does. NIDA keeps its labs in check by sending positive and negative double-blind samples. Lab personnel do not know what samples came from NIDA. If the lab results are wrong, NIDA may take away the lab’s certification. Only labs that perform the GC/MS onsite can be NIDA-certified. Labs that send samples to another laboratory for GC/MS confirmation are ineligible for NIDA certification.
The only lab you should be concerned with is the one that is testing you. Only federal government jobs require NIDA standards. Your typical private employer may use any lab s/he chooses, which would very likely be the least expensive. Businesses don't always choose NIDA labs that follow-up a positive screening test with a confirmation GC/MS.
In the workplace, an EMIT screening is typically used with a CG/MS confirmation if the EMIT is positive. However, this is not a rule. Some employers use the RIA, and some use the hair test. The government uses RIA. They may or may not supervise the subject. Olympic athletes must be monitored by courier after a competition. The courier stays with the athlete until the athlete urinates, with a time frame of up to sixty minutes.
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. It would be too lengthy to list all of the false positives. Jeff Nightbyrd's "Conquering the Urine Test" pamphlet lists a majority of the false positives in detail.
Ibuprofen is a common pain reliever that used to cause a false THC positive on the EMIT test. The EMIT has been changed to use a different enzyme to eliminate false positives due to Ibuprofen. Ibuprofen in very high doses will still interfere with both the EMIT and the GC/MS.
Decongestants and diet pills result in false positives for amphetamine use in one third of the test samples given to 40 of the country’s leading laboratories. There are roughly 300 over-the-counter drugs that cause false positives on the EMIT.
There is speculation that some antibiotics (such as Amoxicillin) cause a positive test result for heroin.
Melanin is the brown pigment that protects your skin from UV rays. It was raised as a discrimination issue in the 1980s as people argued that melanin's molecular structure is similar to that of a THC metabolite. Subsequent research revealed flaws in the data. Melanin was found to have no effect on THC metabolite testing.
DHEA, taken by patients with HIV, will cause a false positive for anabolic steroid use.
“Caine” products (like Novocain) used in dentistry have been known to cause false positives for cocaine.
Some legal products actually contain small amounts of illegal chemicals. All tests, including the GC/MS, will test you positive because the metabolites derived from the true positive are identical to the metabolites of the illegal drugs. One exception: poppy seeds will not cause a positive GC/MS (explained below).
Poppy seeds contain traces of morphine and can lead to positives for opiates. According to Dr. Grow, eating a pastry filled with poppy seeds will cause results showing that you are a high-level opiate user. Harold Crossley, a nationally known chemical dependency expert, said you would have to eat about 100 poppy seed bagels to score a positive on a drug test. When taken into account that very few poppy seeds are sprinkled on bagels, you can see that poppy seeds from a hundred poppy seed bagels will easily fill a single large pastry.
Purim cookies, a Jewish food known as Hamantashen, may have five to six tablespoons of poppy seeds. A couple of Purim cookies may cause a positive test. Poppy seeds can be distinguished from illicit drugs on the GC/MS test. Although poppy seeds have the same metabolites as opium, these metabolites are shown to have different patterns when viewed with the GC/MS.