Sunday, February 14, 2010

Drug Testing Technologies:Sweat Patch

Drug Testing Technologies: Sweat Patch
A recent innovation in the science of drug testing, the PharmChek Drugs of Abuse Patch - or "sweat patch" - is used to test for various illegal drugs. The sweat patch is affixed to the skin in much the same way as a band-aid, and is worn for up to 14 days. The patch is used to detect the presence of drugs as excreted through perspiration. Individuals required to wear the sweat patch are those on probation or involved in child custody cases. The federal government is currently considering use of the sweat patch in federal workplace drug testing.

The Drug Policy Alliance and DPA Network feel that the use of sweat testing in any of these settings is inappropriate, as published, peer-reviewed research has revealed serious problems with current sweat testing technology. We believe that sweat patch testing poses an unacceptably strong potential for false positive test results. False positives carry serious consequences for tested individuals - sometimes including incarceration or loss of child custody.

If you are involved in a court case where sweat patch evidence is being used, please contact us at Drug Policy Alliance tracks the use of the sweat patch, and in some cases can assist individuals in challenging the use or admission of sweat patch test results.

How does the sweat patch work?

The sweat patch consists of a gauze pad covered by a protective membrane similar to that of a band-aid. The membrane has an adhesive perimeter that sticks tightly to the test subject's skin. The sweat patch is usually worn on the subject's upper arm. Before application, the subject's arm is swabbed with an isopropyl alcohol rub.

After the patch has been worn for approximately seven to ten days, it is removed and the gauze pad is sent to the laboratory for testing. The lab usually performs "screening tests" for several different drugs, using an immunoassay testing system. If any screening test indicates the presence of a drug, the lab performs a "confirmatory test" for that drug, using the more precise "gas chromatography / mass spectrometry" (GC/MS) testing system. If the confirmatory test finds levels of the drug above the "cutoff" the lab is using, the lab will report a positive test result.

Where is the sweat patch being used?

Many counties around the country use the sweat patch to drug test individuals who are on probation, in drug courts, or involved in child custody cases. PharmChem contracts with these counties to sell them the sweat patch testing kits, to perform the drug tests, and to help the counties defend the results in court.

The Administrative Office of the Federal Courts also has a contract with PharmChem. This contract gives individual federal court districts the option to use the sweat patch when they drug test individuals who are on probation or "supervised release" for federal crimes. Not all federal court jurisdictions use the sweat patch, but many do.

How has the sweat patch fared in court?

Each trial court has the right to make its own decision as to whether sweat patch evidence will be admitted, and how that evidence will be used. A decision by an appellate court would govern the trial courts in that appellate court's jurisdiction, but so far there are no appellate court decisions on the sweat patch from either state or federal courts.

Many trial courts have considered the sweat patch. Some courts have admitted sweat patch evidence, and relied on it in deciding to imprison probationers or terminate parental custody. Others have found the sweat patch insufficiently reliable for these purposes: at least six different federal courts have rejected government efforts to base punitive action on sweat patch test results.

While Drug Policy Alliance tracks court decisions on the sweat patch, many of these cases are confidential, and hardly any have resulted in written court decisions. There is no exhaustive list of court rulings on the sweat patch. Only two courts have issued written decisions that discuss the science behind the sweat patch and are published in official legal case reports.

§ U.S. v. Snyder. F.Supp. 2d. 2002 WL 257381 N.D.N.Y., 2002. This recent federal court decision finds that in certain circumstances, the sweat patch can be environmentally contaminated, leading to a false positive test result. Because the defendant in this case made a plausible case that his positive test results were a product of environmental contamination, the court rejected the use of the sweat patch to revoke the defendant's supervised release.

§ U.S. v. Stumpf. 54 F. Supp. 2d 972 D. Nev. May 31, 1999. This federal court decision finds sweat patch evidence admissible, and rules that it can be used as the basis for revoking an individual's supervised release. This decision was issued prior to the release of several scientific studies that indicate problems with the sweat patch. The decision contains virtually no scientific analysis: the court simply describes the views presented by each side's expert, and then states that the court agrees with the government's expert.

What are the problems with the sweat patch?

The problems with the sweat patch are many:

False positives through environmental contamination. Scientific studies have demonstrated that environmental contamination can produce false positives in the sweat patch.

Naval Research Lab study. This study by the United States Naval Research Laboratory found that the sweat patch is susceptible to environmental contamination through two scenarios:

"Contamination from within": Environmental contamination may occur when a test subject has a small amount of drug residue on her skin where the patch is to be placed, and the isopropyl alcohol rub fails to remove that residue. The sweat patch will then pick up that drug residue, which becomes indistinguishable from drugs excreted through the subject's sweat, resulting in a false positive test result.

"Contamination from without": Environmental contamination may occur when drugs in the environment leak through the protective membrane covering a patch that is being worn. This situation is more likely when the membrane is wet and when it is exposed to a substance with a high ("basic") pH level. This is the environmental contamination scenario that led to the rejection of sweat patch evidence in U.S. v. Snyder .

PharmChem's internal studies have duplicated the results of the Naval Research Laboratory Study in finding that "contamination from within" can occur. PharmChem has refused to release or publish the results of these studies, but the studies were described in detail in the recent court hearing in U.S. v. Snyder .

Studies designed in consultation with PharmChem and conducted at the Center for Human Toxicology in Salt Lake City also duplicated the results of the Naval Research Laboratory Study in finding that "contamination from within" can occur.

False positives through skin storage. A recent study suggests that long-term storage of drugs in skin could lead to false positive test results. See Levisky, Bowerman, Jenkins, and Karch, "Drug Deposition in Adipose Tissue and Skin: Evidence for an Alternative Source of Positive Sweat Patch Tests," Forensic Science International 110 (2000) 35-46. The study indicates that chronic drug users may store drugs under the skin surface. These drugs may be released a long time after drug use so that "a sweat patch, used as a detection device, might falsely indicate that new drug use had occurred." Such false positives are a particular concern to the many individuals who have been heavy drug users, have conquered their drug habits, and are currently being tested by the sweat patch.

False positives during application and removal. Application and removal of the sweat patch are usually performed by non-medical personnel, in a non-clinical setting. Patches are often applied and removed in a probation office by probation officers who have received only a videotaped training. Any sloppiness or failure to follow proper procedures can easily result in false positives. PharmChem officials have themselves admitted that a there is a risk of false positives during application and removal. Indeed, one study indicates that even when application and removal is performed by scientists, in a laboratory setting, contamination can result in false positives. See Cone, Hillsgrove, Jenkins, Keenan, and Darwin, "Sweat Testing for Heroin, Cocaine, and Metabolites," Journal of Analytical Toxicology 18 (1994) 298, 304.)

No dose-response relationship. For any drug testing system, the "dose-response relationship" indicates the test result that one would normally expect to see based on ingestion of a certain amount of a particular drug. This information is central to analysis of the results of any drug test. If one does not know the dose-response relationship for a particular drug in a drug testing system, one cannot make meaningful statements about test results for that drug. And most importantly, one cannot set a "cutoff level" that will distinguish a positive test result from trace contamination of the subject, the sample or the testing system.

No one knows the dose-response relationship for sweat testing. The few attempts at controlled-dose studies have been methodologically inadequate, and have found enormous variability in test results.

In one study, a subject tested at 15 ng/ml after being given a dose of methamphetamine, while the next subject tested at 631 ng/ml, 42 times higher, after being given a smaller dose. (Compare subject # 6 with subject # 7, in unpublished "SCRI" study in PharmChem's FDA submission.) Such wide variations in response between different test subjects are typical. Subjects given 20 ng of methamphetamine, tested six days after ingestion, show results as low as 5.7 ng/ml (SCRI subject # 7) and as high as 905 ng/ml (SCRI subject # 15). These high-end results are in no way aberrational: twenty different tests in the SCRI study alone produced readings above 500 ng/ml; many readings were over 1000 ng/ml.

Substantial disparities exist even with two patches taken simultaneously from a single individual. The SCRI study tested two patches from the lower chest of Subject # 13, nine days after a dose of methamphetamine. One patch tested "negative" at 7.1 ng/ml, while the other tested at 30 ng/ml - a "positive" four times as high. Similarly, the study tested two patches removed from the lower chest of Subject # 5, seven days after the dose of methamphetamine. One patch tested at 34 ng/ml, while the other tested at 185 - more than five times as high.

To our knowledge, neither PharmChem nor any scientist has claimed to understand the dose-response relationship for sweat testing. Nonetheless, PharmChem employs cutoff levels that it claims can distinguish actual drug use from contamination. Without an understanding of a dose-response relationship, however, PharmChem's cutoff level is unreliable.

No regulation of PharmChem's testing program. The federal government does not regulate the use of the sweat patch. PharmChem's sweat testing program is not overseen by the federal government. The federal government does not require PharmChem's sweat testing program to use any particular collection techniques, chain-of-custody procedures, quality control mechanisms, or testing procedures.
All aspects of PharmChem's sweat testing program are designed and operated by a private corporation, without any public checks and balances or quality assurances. No government entity ensures that PharmChem is spending the money necessary to make its tests as accurate as possible. When a company markets a product as a means to catch more drug users, there may in fact be a financial incentive to return positive test results, regardless of accuracy. Without government regulation of PharmChem's testing program, such a dynamic can take effect.

Patch wear problems. The adhesive membrane covering the sweat patch is supposed to bind tightly to the subject's skin, theoretically protecting the sweat patch and preventing tampering. However, subjects routinely report that the membrane does not adhere properly, peeling or rolling up along one or more edges of the sweat patch. This appears to be particularly common when subjects perspire heavily. As far as we know, there have been no studies to determine how often the sweat patch will fail to adhere in real-life wear conditions.

When a sweat patch does not adhere properly, the subject is usually accused of having attempted to tamper with the sweat patch, and is considered as having submitted a positive drug test.

What about rumors that PharmChem has given false testimony about the sweat patch in court?

This memorandum was submitted as part of an ethics complaint filed with the American Academy of Forensic Sciences and the Society for Forensic Toxicologists. It recounts testimony given under oath by Neil Fortner, a vice president of PharmChem, in various court hearings regarding the reliability of the sweat patch. These hearings occurred in cases involving removal of child custody and the threat of incarceration.

The memorandum describes numerous false statements made under oath by Mr. Fortner regarding scientific research on the sweat patch. The memorandum also describes false or strongly misleading statements made under oath by Mr. Fortner regarding his academic credentials. Drug Policy Alliance possesses and can produce copies of court transcripts and other documents referenced in the memorandum.


  1. I can attest personally to the fact that the sweat patch does indeed produce false positives. I am on federal supervision and was ordered to wear the patch. On two separate occassions, I received a positive test result containing THC. I have not smoked weed since 1998. Also, when I was incacerated at CCA in Leavenworth, Kansas there were more than a few women to come through on the basis' of false positives. While we may lie to our probation officers and such, we offenders have no reason to lie to one another.

  2. I was just ordered my my federal probation officer to wear the sweat patch. I have been on probation for over 2 yrs. and only got till Jan of 2013 till Im done and Im really worried that this patch will give out a dirty and they will violate me and back to prison I go. That is not what I want so if anyone could give me any advise as to web sites or what ever for info that there could be a problem with the patch I would greatly appreciate it Thank You

  3. I was just ordered to wear this sweat patch for the sol purpose to go away for the weekend. I am on Drug Court and although I have not done well in the past I am doing very well now. After reading everything i have and researching these patches i do not trust them and think they should be banned from all courts of law until they are completly full proof. These are peopoles lives you are messing with..and for know good reason. Well not for me anyway how are people every supposed to live normal productive lives ..what are we supposed to come back to the company and order sweat patches when we get off papers ..NO!! We learn to live now ..with out people threatening us one day at a time.

  4. i have a CPS case and i am in DDC Court at the family court and i was ordered to get the drug patch on and i am scared because i heard from alot of people that it gives out false positives and if i get a false positive i will lose my kids what should i do because i am scared even though i have not use for a little over 20 months

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  6. I was recently in a 1/2way house for shoplifting. When they did a routine room search they found contraband in my locker; which is always unlocked and open to anyone who walks into our unlocked room. I am now being charged with a felony paraphernalia for some contraption I have never even seen in my life. I went to jail for 11 days and was realeased on the stipulation of The drug Patch Program Through the Cass County Jail In Fargo, ND. I am so afraid of coming back with a false positive especially because the adhesive of the protective sticker over the patch is almost all the way peeled to the drug patch underneath. Who can I have help me if they try to through me back in jail? I have a daughter who will be turning four on June 15th and I have every intention of having all of this taken care of do I can be reunited with he after all the un acceptable harrassment by the ND court system.

  7. I want to know if casual sex with a potional user could cause my patch to give a false positive.

    1. Yes! Definitely

    2. Are we talking marijuana or other drugs?? Cause I smoke & I would hate for my husband to be penalized because if me

    3. Can anyone else expand with more info on this topic please. I am on the patch and I'm very concerned with having a partner that is potentially using, to be more specific THC.

    4. don't have sex of any kind, you will get a dirty patch! I was in jail wit a girl an she got a dirty just from orel sex. and I got a dirty just having sex wit protection. I think im just gonna lock myself in the basement until this is over... good luck everyone.

    5. So if false positive is current on sweat patch, would a hair follicle differ? I came back positive June/ July but have not used. Only way I think this happened is sex with partner who used, or environment contamination.

    6. Did u do the hair follicle? Or what happen! Cus am on the same situation right now

  8. patch does not work!! I have not been using anything and my patch came out positive. I'm also on medox i urine test at least 3 times a week I also attend perinatal classes and test two times a week. how else can I prove I'm not using?? can I argue against the patch??

  9. I have tested positive for the drug patch and i have not used. The only person i would be cheating myself as well as my daughter. I have had relapses in the past but I honestly am clean and fear going back to jail. Im a single parent living in california without any assistance from anyone. Yes, I have made mistakes before and thats why i am on probation and i take responsibility for that but now i am being accused of using . Since i been released from jail i test everyday at my outpatient program and i have been clean. My probation also tests me once a week and all the urine samples i given her have been negative. Its really crazy to think that the courts even use something like the patch when its not even federal government regulated.. Who ever will stand by my side to take action for these matters that have interrupted peoples lives in recovery i will be more than happy to contribute.

  10. hi there i am on probation for 8 years i can sware on my kids that i been clean for 1 month and today recovery health care told me i was postve for meth dirth patch i can sware i have not used we all need to take this to the news and report the people who made up this stupid patch

    1. I understand your pain I hate it aswell

  11. I will be clean 90 days this December 18th, 2013 and i also received a positive patch October 7th, 2013. I just finished Phase I in Perinatal and all of my urine tests have neen clean through them 2 times a week. My husband is still using and ive had sexual intercourse with him and im scared that my patch wil test positive. This to me is all a joke for the system to make money and take peoples children. Its a brutal n cruel place to be n so unfair!

  12. I live in Texas and my drug patch costs $50 every 10 days. I have had 3 patches and I have not had a patch stay all the way on. I don't touch it, I don't let it get wet (hardly at all). The patch comes loose on it's own and when I go in, it looks crinkled up. The two times I have gone in, I am told that I tampered with it. I plead with them that "on my kids lives', I DIDN'T! Pardon my language but FUCK this. I am supposed to go in tomorrow and turn in my third patch, well it's the same as the other two. So I guess they will give me a third "dirty". So it's 2014 and my life is at the mercy of this inferior and unreliable product. Sorry but I can't just sit here and let this happen. I hope the owner of this company reads this because I am going to hire the best Jewish Lawyer I can find and I am going to sue this company.. Your product may be good in theory, but it doesn't stay on. I don't know about all of this false positives and etc, but I know I have not tampered with any of these patches and now I am going to be put in jail. I hope that my efforts help everyone that has suffered from this product. I am not the smartest guy in the world, but the words "class action lawsuit" sure comes to mind. Each time they insist that I tampered with it, I ask them to do a urine test, but they won't. I feel like I am living in a no win world. I always thought that the truth shall set you free. I am telling the truth and the opposite is happening. Please spread the word and maybe there is a way we can stop this unfair punishment. If you have any ideas please email me at It is clearly obvious that something that costs 5 times as much as a UA and promises accurate results.......has a great deal to do with it. This company is accountable for a whole lot of pain and suffering that their product is causing. Our government is just as guilty as far as I am concerned. This fight may be way too big for me to win, but Davey beat Goliath. I promise that I will do everything in my power to fight this

  13. I'm wearing the patch now that im on probation I've been clean for 4 years I had a patch that came back positive for THC the next few where clean [ I change patch every week] Now I thought marijuana stays in you system foe at least 30 days. Then I was wearing a patch and it started coming off so I put a band aid on it to stop it so when I went to change the patch the said it was compromised because I tampered with it so I had to take a UA I told my PO about it and he said as long as my urine was clean I had nothing to worry about then I get call staying that patch was positive for THC now im on house arrest this is some BS. Now he tells me if I have a another positive I would have more problems.


  14. I have been reading and reading about this problem. I too have just been put on the patch and the first two lost the logo which was worn off from normal use. This is regarded as tampering. This is free fifty dollars in the companies pocket because they don't test it. You have the right to challenge the use of the drug patch if you feel you have been falsely accused. There is ample evidence to support the false positives. I would find a lawyer and fight the hell out of the use of this patch. profiting from the misfortunate is unethical and immoral. I am hiring a lawyer and will fight fight fight this till the end. Good luck everyone.

  15. I was wonder wondering if the drug patch test for xanax I been searching and no results just opiates which I'm guessing it will fall on opiates category?

    1. Patch will detect benzos...

    2. i just today got a call from my probation officer informing me that i have a dirty patch for meth. the only thing i can think to say n my defense is that it had to b somewhere n my environment i at all times take precautions to not b n a place that this can happen sometimes it is unavoidable when it comes to ur family and thats sad. i rather pee n a cup everyday then wear this patch and have this happen again this is my life this gosh forsaken piece of crap is ruining i wish they would do away with this thing.

    3. i just today got a call from my probation officer informing me that i have a dirty patch for meth. the only thing i can think to say n my defense is that it had to b somewhere n my environment i at all times take precautions to not b n a place that this can happen sometimes it is unavoidable when it comes to ur family and thats sad. i rather pee n a cup everyday then wear this patch and have this happen again this is my life this gosh forsaken piece of crap is ruining i wish they would do away with this thing.

    4. Damn lover. I'm about to go an the patch when I start my probation n a wk. I'm scared! I don't want it to come back positive becuz I finally got my life together and don't even wanna c that shit again. I have a 3 1/2 yr old son to worry about, so there's no time to think about that shit. Who is ur po? Love u lover, so much. Does the patch test for alcohol?


  16. Drug patch being used in my boyfriends probation violation hearing. He was put on the drug patch April 8th, and so far the first three patches have been positive. I know for a fact he has not used meth since March 2014. He tested positive with the drug patch on 4/23/2014 38.0 ng, 05/07/14 101.0 ng., 05/21/14 71.0 ng. He tested negative for Amphetamines. (How is that possible. I thought Meth was derived from Amphetamine?) The point is he has quit using and hasnt used since the patch was put on him.

    He tore up a floor in one of my Mothers rental houses and ingested dust and ????. He went to the Dr.on 4/10/14 and they prescribed the following: GNP Allergy,

    Proair HFA AER, Benzonatate 200mg, and Azithromycin 250 mg. He was taking about every over the counter cold and flu med available and was not getting any better. He had an infection in his lungs. After fighting fever and absolutely feeling terrible and unable to breath, he went to the emergency room at 3:30 am on 05/09/2014. They thought he had pneumonia and xrayed his lungs, gave him a breathing treatment.(Albuterol-ipatropium) Then they did a CT Scan with contrast and another breathing treatment. He was told he was very sick with bacterial infection in his lungs and that he had Emphsema and COPD. He was prescribed the following Doxycycline HYC 100mg and Albuterol-ipratropiumCCFC free 100 mcg-20 mcg/hh.

    After the patches can back positive he went to lab and submitted to a hair folicle test and the test came back positive for Amphetamines. If the test went back 90 days that is possible, even though his drug patch showed negative for Amphetamines We called and were told they do just a positive or negative test. They dont break it down for usage in 30 day increments, he had already been written up for a dirty UA in March.

    His attorney whom we have paid large amounts of money will no longer handle his case. She told him if he tested dirty that he was on his own. The problem is he is not dirty but the patch has said otherwise. He is a good guy and they are talking about giving him 4 yrs. He has never been in trouble and should of never pleaded guilty to possession in the first place. The law firm believes in the patch, (it is a family business) and there is no convincing his attorney that he has not done any drugs. Her sister owns the lab company who monitors and applies the Pharmchem Drug Patch. It is a very strong conflict of interest.

    The patch is a joke it is not accurate and reliable. It is putting innocent people in jail and I will do whatever it takes to make myself heard of how wrong this device is.

  17. Sex wont cause positive ws long as patch diesnt come in contact with partner's fluids. Just one drop of sweat will cause positive. Cover your patch yourself. The lining of the patch is made off a semi permeable membrane f
    That allows certain drug metabolites to transfer, but not all. Do your own testing as backup. You have to pay our of pocket, but who cares how much it costs....your denial will never amount to what your own negative result will. I have gotten numerous hair follicle tests done right at the same time the patch was removed that way i will get my negative results the sane time the oatch results come back. So if there ever was a positive i have scientific proof that their shit patch is rather be bald and broke paying for negatice proof than sitting in jail crying.