So as of July 5 I was 105-107 days clean of marijuana & took a hair drug test for a really great job. I AM BEYOND STRESSED RIGHT NOW! I am not & never hve been a smoker of any type.. I smoked about 3 or 4 times in feb & early march (about 4 puffs each time). I did not use any sort of detox or anything prior to test... wat are my chances of passing/failing?

If you took 4 puffs 4 times over 3 months ago you should be OK?

Hair Drug Tests (HDT) are relatively effective at detecting heavy use of certain drugs-Not very effective at detecting infrequent use of most drugs.

Cannabis use generally isn't detected by HDT except in regular and heavy users.

In your case the time span is less important than the quantity smoked and frequency of use. Very unlikely that THC or COOH were incorporated into hair, and if so, at detectable levels.

Should be OK.

Thank you so much! This eases my mind so much! Also my hair has grown quite a bit since then so I'm praying for good test results. I will post my results nxt week

For any hair follicle test I've ever seen it's yanked out, roots and all. There is no way if there are traces that they've grown out since March/April.

From what I was told only the hair closest to the root is tested.. the new growth would not be infected unless drugs were used...

I only know what the Feds did when I worked for the Feds. It was yanked by the roots and the strand tested.

Oh.. mine was cut close to the root and the part closest to the root was tested

Process of Hair Drug Testing (HDT)

HDT is often referred to as hair follicle tests. That is misleading as it is not. The test has nothing to do with testing the follicle and, in fact, HDT doesn't test your hair at all. The hair shaft is but a container used to deliver the drug (or not) to the testing facility. The follicle is the sac from which a hair grows and into which the sebaceous (oil) glands open. The follicle lies below the scalp or skin surface and is lined by cells derived from the epidermal (outside) layer of the skin. Only the hair shaft that part of the hair that projects above the skin, is used in HDT.

Step 1 Hair sample. The sample is cut from your head-as close to the scalp as possible. About 100 hairs strands are required (a section about the size of a pencil) The hair follicle is not disturbed. Those hairs are sent to the testing facility.

Step 2 Decontamination. Removal of external contaminants. A portion of the hair sample is placed in a receptacle and subjected to a chemical wash of one type or another. This is determined by the choice of the laboratory as well as the characteristics of the drug or drugs being tested for. The cleansing solutions/methods vary in ability to decontaminate the hair. The decontaminant ideally will cleanse the exterior of the hair without destroying or diluting the quantity of the drug(s) within. The effectiveness of this step, when properly performed, may vary from 65-93%. None are 100%. So there is always the possibility for external contamination to register on the test, as you will see following.

Step 3 Extraction. There are currently no direct methods for the detection of organic drugs in hair. Therefore drugs must be extracted by solubilisation or digestion of the hair matrix itself. That means that the hair sample is destroyed in order to get to the contents contained within. A method used for pulverizing the hair sample is a ball mill ball mill - Google Search or it may be chemically dissolved. Once the hair has been reduced to a solution or powder then it is necessary to separate the waste products (actual hair byproducts still remaining) from the drug. An example of the method used is Headspace Solid Phase Microextraction (HSPME). Other methods for solubilisation and separation are also used. NOTE: Any of the specific drug that was not removed in Step 2 would now become part of the sample to be tested. Therefore the danger of external contaimination.

Following the steps noted above, all remnants of the actual hair are now gone and the drug test begins and from this step forward testing is similar to urine testing.

Step 4 Initial screen. Enzyme-immunoassay antibodies (EIA) or other immunoassay techniques similar to those used to test urine are used for the initial screening test for drugs of abuse in hair; therefore the potential for substances such as over-the-counter medications to cause a false positive screening result does exist. However, the vast majority of errors are false negatives because IA are far less sensitive than the instruments used for confirmatory testing. To eliminate the possibility of reporting a false-positive due to cross-reactivity or other means confirmation testing is essential.

This step cannot identify a particular drug. Only a class of drugs, so an opioid is detected by the presence of morphine (all opiates break down into morphine). So any opioid would return the same positive result but could not be individually identified.

This phase of testing (immunoassay) usually uses a higher cutoff and is far less sensitive than the instruments used at the confirmation step if that occurs.

However, the test ends here unless the sample shows positive for one of the drugs tested for.

Step 5 Confirmatory test. This is the highly sensitive part of HDT although the same instrument is used as in most other drug tests such as urine or blood. An instrument called LC/MS/MS or equivalent is used and capable of measuring down to very low level Picogram = one trillionth of a gram (0.000 000 000 001). In addition, this technology can identify millions of specific drugs and metabolites. It compares them to a data-bank of spectograms (kind of a molecular fingerprint).

The biggest factor influencing test reliabiliy at this step is human error, carelessness on the part of people doing the testing or using a machine that has not been properly cleaned or re-calibrated.

The equipment and technology used in Step 4 (immunoassay) can and does return false positive results (more often false negative). Step 5 should detect that error. The results of a confirmatory test (LC/MS/MS) result is never considered to be a false positive. However, false negatives are not detected because the test does not progress to confirmation.

It must be kept in mind that while the instrumental result might be correct it is still possible for the results to be diagnostically incorrect. As example identifying drug contaminates that resulted from a mistake in Step 2. That is analytically correct (a true positive for drug) but diagnostically incorrect as the drug was not ingested.

The commercial testing labs place great emphasis on the use and sensitivity of confirmation instruments. The vast majority of HDTs end with a negative return at screening (see 4 above) never advance to confirmation and are therefore never subjected to the sensitive instrumentation so widely advertised.

Ref:
Mass Spectrometry Procedures
Guidelines for Testing Drugs et seq (pp 4-11)
Society of Hair Testing (SoHT), 2011

Today marks a week since I've taken the test and I was told results would be bak by Tuesday... im praying that this is a good sign! Thanks again for the input

I passed my test!!

Good for you. Hope you prosper in your new job.

Thank you so much.. lesson vry much learned!

Dr Bill, firstly, thanks for all of the information and cited sources. You mention that infrequent drug use of any kind would be undetectable by HDT. Does that mean zero drug or metabolites will show in the test results or perhaps you meant it would be undetectable below a certain threshold? I had hair harvested for testing exactly 90 days from when I last used cocaine and hadn't used in years prior to that. The cocaine was low quality and the quantity ingested was moderately low as well? The harvested cut of hair was about an 1/8 of an inch from the scalp and I am freaking out as most of us reaching out to you are. This is for a child custody case that was just dropped in my lap... damn ex wife and attorneys. I believe the lab that is testing my hair sample has cut-offs at 150 and 300 to be considered negative. I'm not sure which threshold the court requires. Any thoughts from you? Thanks for you for your input...