What You Should Know About Testing for Alcohol in Urine
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Please Note: The following is presented as general educational information. It is not legal advice, either expressed or implied. Consultation with your legal counsel is recommended for all matters of employment law.
Of all the drugs tested in workplace drug testing programs, the most abused drug and the one that poses the greatest hazard is the only one that is legal without a prescription - alcohol.
Alcohol is the most commonly abused drug in this country, and it is also the only one where a legislated impairment level exists. This legislated impairment level creates a unique situation because it makes alcohol the only tested drug for which there is a direct relation between test result and impairment. For an employer, it is relatively easy to decide what to do when it is known that a tested employee is legally impaired, but it may not be so easy to decide what is to be done when testing indicates presence of alcohol below that 'legal impairment threshold'.
There are many questions to be addressed, but two requirements must be present at the start and throughout the process:
1. A scientifically and forensically valid testing technique that produces a clear result, and
2. The ability to reliably compare that result to blood alcohol, which is the benchmark for legal impairment.
Before testing begins, employers should decide whether the intention of the testing is to detect only the presence of alcohol or to detect impaired employees. Each goal has its own set of difficulties and advantages, and this decision should be primarily based upon the employer's needs and philosophy. Clearly the choice of specimen type to be used in the testing is to some degree dependent upon the goal of the testing. Urine alcohol levels do have some relationship to impairment, but impairment is much more easily and forensically discovered using breath or blood specimens.
Disadvantages of Testing for Alcohol in Urine
Urine alcohol testing has the advantage of being inexpensive and easy to do in cases where urine drug testing is already in place, but it also has a sizable number of disadvantages.
The limitations of urine alcohol testing become clear when taking a broad look at what happens to alcohol in the human body after it has been consumed. The alcohol metabolic pathway is divided into stages:
1. Absorption (30-60 minutes after ingestion)
Distribution, metabolism and elimination may be grouped together and called the post absorption stage. As noted, absorption may take as long as 60 minutes depending on many factors, but the post absorption stage may be much longer since alcohol is removed from the body at a rate that is constant over time but which may vary from 0.003-0.030 ml/hour. The population average is 0.015 ml/hr. Alcohol that has been removed from the blood to the urine may pool in the urinary bladder for hours after its metabolism has been completed.
Given the above, the main disadvantage to testing for alcohol in urine is the difficulty in relating the urine concentration of alcohol to the legal benchmark, which is blood alcohol. There are computations that can be used to do this when the urine sample has been collected according to an established protocol that requires a two void collection over a 20-30 minute period of time. These computations can give an estimation of blood alcohol level during the post absorption phase of alcohol metabolism, but they are very collector dependent. The collector must exactly follow a very specific collection protocol; and must collect a very accurate history from the donor about the time of the last alcoholic drink and the time of the last urine excretion. Either of these things may be complicated to obtain, and by their absence or inaccuracy may cast doubt upon the computations relating the urine result to the blood alcohol level and therefore upon the level of impairment of the donor.
Another complicating factor which diminishes the value of urine alcohol results to the employer is called "Tolerance". "Tolerance" allows heavier drinkers to metabolize and excrete alcohol more quickly than light or non drinkers. If tolerant and non-tolerant drinkers have urine specimens collected for urine alcohol testing at the same time after the same number of drinks and using the same collection process, the heavy drinker is likely to have a very different result than the light or non-drinker.
The timeline of alcohol metabolism independent of tolerance is a further complicating factor. It is possible that a urine drug test specimen collected in an early morning void will still contain alcohol consumed the evening before. How will this be addressed in the workplace when there is no indication of impairment and when the alcohol has been consumed legally during non-work hours?
With the ease, availability and forensic history of blood and breath alcohol testing, urine alcohol testing should be used today only for those employers who are already collecting a urine specimen for other drug testing and for whom cost, time, or other constraints determine that urine alcohol testing is the only viable alternative. Given the aforementioned problems with urine alcohol testing, how these employers handle the results of the urine alcohol test may vary widely and should be clearly explained in company policy.
There are more reasons that urine testing is not generally accepted as the best way to conduct alcohol testing. The concentration of alcohol in urine is generally accepted as 1.3 times the blood concentration when measured after peak absorption, but there are two factors which impact the authenticity of this value:
1. The ability of a tolerant individual to metabolize alcohol more quickly than a non-tolerant individual, and
2. The possible presence of Candida Albicans in the urine specimen.
Candida Albicans is a ubiquitous yeast that is known to ferment sugar into alcohol. Sugar is frequently present in the urine of diabetics and sometimes transiently present in non-diabetic urine. Most laboratories that conduct urine alcohol testing automatically test for and report the presence of sugar in the urine specimen. When that presence is reported to a Medical Review Officer (MRO), in the vast majority of cases the MRO overturns the result and reports a negative result because there is no way to definitely know the real source of alcohol in a urine specimen. While the impact of tolerance and the presence of Candida in results cannot be determined, it cannot be ignored. MROs and employers using urine alcohol results as the basis for disciplinary action need to be prepared to scientifically and legally defend those actions. Such defense may not be easy.
Best Uses for Urine Alcohol Testing
A clear and specific policy statement needs to be in place before any drug test results are acted upon. This is especially true for urine alcohol. What is the goal of the testing? What testing is to be done? What will be the employer action if a positive test result is received?
The best use of urine alcohol testing may be in situations where abstinence is a requirement. This is obviously the case in substance abuse treatment programs. It may also be the case where employers and employees have entered into a return-to-work contract or a last-chance agreement that demands abstinence on the part of the employee.
If urine alcohol testing must be used, the employer must have confidence that the result is indicative of alcohol use and not indicative of a fermentation process, such as that done by Candida Albicans in urine. A specific alcohol metabolite called ethylglucuronide (EtG) has been suggested as useful in this process, but use of this metabolite is very controversial.
EtG is an ethanol metabolite, and it is not found in urine as the result of yeast fermentation. EtG is present in urine up to 80 hours after the alcohol has either been consumed or contacted. Although this long urine detection period renders EtG testing useless in identifying impairment, the long timeline may be a benefit when the testing is used in abstinence requiring programs. There is no relationship yet discovered between EtG and blood alcohol, so it can only be an indicator of alcohol exposure, not impairment.
For EtG to be used as an indicator of alcohol use, it is necessary to have confidence that the detection cutoffs effectively eliminate the possibility of positive results coming from any form of innocent use. Currently there is no scientific agreement about what cutoff level should be, if indeed such a cutoff even exists. Indeed there is some data showing EtG positives from ingestion of orange juice that has been kept past the expiration date and undergone a small amount of fermentation, and from alcohol absorption through the skin after the use of alcohol-based lotions and skin creams.
SAMHSA has just issued an advisory warning against the use of EtG as the "sole evidence that an individual prohibited from drinking in a criminal justice or regulatory compliance context, has truly been drinking."1
EtG testing is conducted in the same general manner as all other workplace testing for drugs of abuse. An initial or screening test is performed using an immunoassay technology, and then a screening positive is confirmed by a separate technique. The best confirmation technique is LC-MS/MS (liquid chromatography, tandem mass spectrometry). This has been shown to be superior to the standard GCMS confirmation used in most forensic workplace testing because of the chemical properties of EtG, however, not all testing laboratories employ this technique. Before any EtG program is implemented, it should be verified that the chosen testing laboratory employs LC-MS/MS.
Additionally, not all laboratories test for EtG in any manner. Costs also vary widely, with one laboratory charging $115 per test, another charging $21. Urine alcohol may be added to an existing forensic panel for as little as a $.50 laboratory fee. Of course, this does not take into account the increased collection costs both in time and collector effort due to the two void collection protocol. In addition, MRO time and effort to compute a valid blood to urine alcohol result must be considered. In most cases of urine alcohol testing today, the two void collection is not used, and the MRO may or may not be asked to equate the urine result to blood. One must question, therefore, the value of such a result.
From a scientific perspective, there is no compelling reason to do urine alcohol testing in a workplace setting. While arguments can be made relating urine alcohol concentration to blood alcohol concentration in conducted and processed in a highly controlled setting, it is a labor intensive means of determining blood alcohol. A more definitive and defensible result can be obtained by collecting blood or breath alcohol.
In programs requiring abstinence where the only interest is detecting any alcohol consumption whatsoever, EtG may be preferable to urine alcohol testing. EtG does not have the attached risk of yeast fermentation causing a false positive, but currently it cannot be said definitively that EtG presence is caused only by the prohibited consumption of alcohol.
Questions related to this information may be directed to Verifications, Inc. Compliance Department at 763-420-0600. For information about Verifications, Inc. employment screening products and services, please contact Verifications at 1-800- 247-0717, visit our website at www.verificationsinc.com, or email us at