How Long Do Toxins Remain In Hair?

Hair testing generally uses 1-1/2 inches of hair, representing about 3 months’ growth (head hair normally grows at about 1/2 inch per month). It is generally accepted that in order to test positive, the drug in question must have been used 3 times or more within the window of the test. After a drug is used, it takes about 7-10 days for the hair containing the drug to grow out of the scalp enough to be cut. Therefore, the hair test will not include drugs used in the week prior to the test. The drug remains in the hair, growing out much the same as hair dye and "dark roots". Eventually that hair containing the drug is cut off with normal haircuts.

Drug Test Passing - False Positives

False positive drug test passing results can be attributed to human error and sample contamination. In addition, there are a number of controlled and uncontrolled substances that will cause a false positive result; these are some of the reasons why drug test passing labs will immediately split your specimen into two samples. Below are some of the many substances to avoid prior to drug test passing. Take this very seriously, your employer or probation officer certainly will. False positives run high with the EMIT, and in some cases this is all it takes to send you to the unemployment office or a parole/probation revocation hearing. National laboratories state that the EMIT test is wrong 25% to 30% of the time, and can result in false positives from legal substances up to 38% of the time!

Antibiotics: Certain antibiotics such as Penicillin and Tetracycline can cause false drug test passing results for heroin or cocaine.

Cold remedies, diet pills, hay fever remedies and pain relievers: In blind drug test passing testing, decongestants and many diet aids resulted in false positives for amphetamine use in one third of all drug test passing samples given to 40 leading substance testing laboratories. There are more than 300 over-the-counter drugs that can cause false drug test passing positives on the EMIT, and new drugs being introduced every day. Some others include: Cold and allergy meds that contain ephedrine, pseudoephedrine, propylephedrine, phenylephrine, or desoxyepherine (Brand names include Nyquil, Contact, Sudafed, Allerest 12 hour, A.R.M., Triaminic 12, Ornade, Tavist-D, Dimetapp, Sinex, Neosynephrine, Actifed, Bayer Select Maximum Strength Sinus Pain Relief Caplets, Contact Non-Drowsy Formula, Dristan Cold Caplets, Maximum Strength Sudafed Sinus Caplets, Maximum Strength Tylenol Sinus Gelcaps, Sinus Excedrin Extra Strength Caplets, Drixoral Cold and Flu, Robitussin Cold and Flu, Vicks Inhaler and Afrin)
Diet aids containing phenylpropanolamine (Brand names include Dexatrim and Accutrim). Asthma medications such as Marax, Bronkaid tablets, and Primatine Tablets.

Dental/Medical treatments: Cain-based products, especially Novocain, have been known to cause false drug test passing positives for cocaine. Some legal products actually contain small amounts of illegal chemicals. All urine tests, including GC/MS will indicate a positive drug test passing result because the metabolites derived from the substance are identical to the metabolites of the illegal drug.

Ibuprofen is a common pain reliever that, even in low dosages, can cause a false THC drug test passing positive on the EMIT. This has supposedly been corrected. Here are some other common ones as well: Advil, Nuprin, Mediprin, Motrin, Bayer Select Pain Relief Formula, Excedrin IB Caplets, Genpril, Midol 200, Pamprin, Trendar Cramp Relief Formula, Cramp End Tablets, Medipren, Rufin, Naproxen, Aleve, Keroprofen, and Orudis KT.

Poppy seeds: Though an extremely concentrated amount of poppy seeds are needed to obtain a false drug test passing positive for opiates on the EMIT, it is possible.

Read more about different types of drug test passing.