comment: >
  
  Why is this a bigger problem for pot than it is for alcohol? Surely someone could drink before a shift as easily as they could smoke, why aren't employers testing for alcohol use before you clock in?
context: Just a side note: I had a job as a medic mostly on construction sites and it involved both pre-employment and post-injury drug tests. It’s not just a weed test. Meth, and especially coke, are also very common to find, and I’d say I found non-negative results for coke maybe 60% as often as I would find them for weed (in a recreational legal state). The reason is obvious in that construction workers know they’re likely to get tested at unpredictable intervals due to injuries, so more choose things like coke that are out of their systems fast. >
  
  No one seems to be pointing out that we are testing for THC-COOH a metabolite of weed that happens to be fat Soluble and why it stays in the human body for so low. No other drug on the 5 or 10 panel is tested this way. You can do a blood test for Delta 9 THC but it's not detectable within 48 hours. >
  
  If there was a test that existed that could identify whether you were still under the influence of weed as opposed to just having some in your system, would you be opposed to that test being run? >
  
  In this very hypothetical hypothetical, are all drugs being treated the same (or at least are the users of least intoxicating not being disproportionately punished? Is each drug detectable for the same length of time? >
  
  That's not really relevant to my point. I am asking if such a perfect test existed, would OP be averse to being tested for marijuana before being allowed to work, regardless of any other drugs test. i.e. is the issue that they are testing for marijuana in the first place, or is the issue that the testing being used is an imperfect indicator for inebriation? >
  
  I didn't mean to sound dismissive of your question. I just didn't think giving an answer one way or another would change the conversation.
  So let me answer your question: no, each drug acts as it does in reality. And no, punishment is not the same: If you have traces of legal drugs but are "under the imit" there is no punishment. If you are found to be "over the limit" on a legal substance, you get fired or sent home until you are sober. If you are found to have an illegal substance you get fired and reported to the cops. >
  
  I'd accept this in a heartbeat. Pretty good as a wish list. I would imagine it would allow for a lot more welcome room for reasonable discretion perhaps. >
  
  I enjoy cannabis, and I’m thrilled that legal states are slowly getting closer to my area. However, as someone who works in a technical capacity (not patient-facing) and takes long breaks from cannabis from time to time, I can tell you that having THC in your system absolutely impairs you beyond the acute phase of intoxication.
  Now. It isn’t a night-and-day thing. You can definitely function at a high level with THC in your system. But when it comes to certain professions (pilot, surgeon, etc), I don’t want to take even a 5-10% reduction in cognitive ability, because when the shit hits the fan, you’ll need all your faculties. 
  Where I do agree with you is the general drug screening for regular-ass jobs. Cashiers, accountants, etc etc. No reason to discriminate against cannabis users there. But for professions involving safety hazards… yeah I’m ok with it. And say this as someone who has smoked acres of the stuff in my time. >
  
  Salutations. 
  I am a GSP with a degree in safety management.
  I am all for Marijuana being removed from job hiring screenings. 
  However. Should an accident occur I believe in a full drug screen. Reason being since we don't have enough data to determine if its a safety factor or not due to it not being federally legal. 
  However. We can observe a 12% increase of fatal crashes on the stoner holiday 4/20
  This indicates to me that while there are functional stoners even the most experienced stoner can over indulge and get hurt. >
  
  So to start, I am in Canada so I acknowledge right off the bat that things are a little different here, however...
  
  Weed is legal in the whole country for 19+ 
  Drug testing for jobs is illegal EXCEPT when working in vulnerable persons sectors and high-risk installations (e.g. nuclear power plants, etc.)
  
  You aren't prevented from having a job if you smoke weed, you are prevented from working on specific projects. Those projects by and large involve working in and around people/children who would be less likely to be capable of saving themselves from danger if you made a mistake due to residual drug effects. It takes marijuana much longer to metabolize out of your system, which means by its very nature you are unable to claim you are 100% "sober" (even if you aren't feeling any effects anymore), so insurance companies won't cover any accidents in which the person who caused the accident doesn't present a clear drug panel. 
  Case in point: an accident occurred on one such job site in Ontario where someone driving a mini-crane carrying a slab of granite accidently dropped it on another worker, killing him instantly. Despite the fact that safe practice dictates for this very reason that no one walk beneath a hanging slab (so by that logic the worker who died was "at fault"), the driver of the mini-crane was tested and it came out that he had been drinking and smoking weed the night before. The legal argument is made that having even small residual amounts of drugs in your system could have SOME effect on your reaction time/decision-making abilities, and that split-second difference COULD be the difference between life and death. In this case, the burden would be on you to prove that there's ZERO chance that the residual drugs effected the driver's abilities, and there just isn't a way to prove that. Hence, zero tolerance policies. 
  I suspect the marijuana-vs-other drugs issue will change over time when more studies are done that can indiscriminately prove the effects are gone within however many hours/days. But until such a time, those tests are there for a reason. >
  
  
  You can drink alcohol 6 hours before work and no one bats an eye
  
  Well, this isn't true. If the alcohol is still in your system, and it comes out in a drug screening, it can cause you to fail the test. And especially for jobs involving heavy equipment and / or operating a vehicle, testing positive for alcohol in a drug test will cause you to fail the test.
  Rightfully so, since alcohol in your system means you're still being affected on some level.
  The problem with weed is that it can be difficult for most test to distinguish between recent use and the sort of residual presence that could still be there a week later. This is also one of the big reasons why there's such an issue with pot legality in general. The means to test for its active presence in DUI situations still leaves a lot to be desired.
  The big problem is that weed is not universally legal in the US, but varies in its legality from state to state and is still illegal federally. That means that companies are within their rights-- even in a state where it's legal-- to deny employment based on weed use.
  What needs to happen is two things:
  1) a test needs to be developed that's capable of identifying when someone is actually under the influence of weed, and after that
  2) the federal prohibition against weed needs to end
  But until #1 happens, I'm okay with it being illegal. Just as with alcohol, we need to be able to reliably prohibit people from casual use in situations that could endanger other people or themselves. As it stands, I live in an area where weed is easy to acquire, and I smell it coming out of cars all the time. Sorry, but I'm not okay with that. Regardless of what some potheads say, weed does cause changes in perception that can negatively affect reaction time, decision making, and judgment, and those are things that shouldn't be influenced when someone is driving a vehicle. >
  
  Law enforcement doesn't do urine tests to determine intoxication. They use blood tests for drugs.
  Urine tests do nothing to test for intoxication because they're not actually testing for intoxication in the first place. They're testing for the metabolites, ie what your body turns the psychoactive compound into after it has been denatured and is no longer psychoactive.
  I have no issue being tested by blood to see if I'm intoxicated while driving. I have a big issue being tested for past use when I am sober, and losing my job for something legal I did on my own time.
  Source: have been convicted of DUI-Drugs, got a blood test at the county jail/police station. >
  
  
  I have a big issue being tested for past use when I am sober, and losing my job for something legal I did on my own time.
  
  Welcome to a country of at-will employment.  You can be fired for liking the Red Sox more than the Yankees.  It's terrible and needs to change, but workplace drug tests are one of the smaller symptoms of it. >
  
  I think more people are terminated for failing drug tests than for sport team preferences. >
  
  At Will employment means people are terminated for whatever the hell the manager wants to terminate for.
  With some exceptions, companies don't have to terminate you for a failed drug test.  
  Honestly, that's what happens when a country won't protect its workers. >
  
  I am going to go beyond your position OP and argue that ~~routing~~ routine drug screening should be dropped in all cases, for all types of employment. The issue is not that marijuana sticks around for longer than other drug metabolites, the issue is that our drug tests are flawed in the context of employment.
  Put simply, recreational drug taking in and of itself is a matter between an individual and law enforcement. If an employee is convicted of a drug related crime then an employer should be free to fire them, but we don't allow vigilante justice and firing people for the suspicion of crimes (or at least we shouldn't). A drug screen cannot possibly demonstrate that a law has been broken; the person might use prescribed marijuana or have been injected with cocaine as a local anaesthetic.
  Where drug use is the concern of an employer is where it leads to impairment of the employee's ability to do their job. This is of course grounds for disciplinary action or even firing. However at present with the exception of alcohol we have no tests for drug-induced impairment. It is thus impossible to say whether a positive test for drugs has resulted in impairment of the worker during work time.
  It seems to me that the impairment itself is the issue, and that can be grounds for disciplinary action without any need for a drugs test. Someone who comes into work excessively tired and falls asleep or makes lots of errors would be reprimanded or fired, and they would of course pass a drugs test. Does that logic make sense?
  On a different note, I also believe that the benefits of routing drug screening are negligible in terms of improving workplace safety, as demonstrated by the lack of excess problems in places where such screening is illegal. However the damage is high: screening can be used as an excuse for not hiring people, and it is open to significant opportunity to discriminate against those on prescription medication who may well be protected as disabled but will in practice struggle to fight against a failed drugs test.
  Does my argument persuade you at all? >
  
  But but prescription drugs, no eyes batted!! Seattle legalized weed in 2012 and employers still test here. Ntm, people are still in prison for charges relating to marijuana. It’s all political/$$$$$$ nonsense. >
  
  Not quite the same thing. I'm on a prescription drug to stop my heart from beating too fast. If I were to not take it and then drive a car it would put myself and others at risk. Arthmas inhalers are prescription drugs etc. >
  
  Funny, I have a medical marijuana card which means it’s a prescription yet I could still not be hired in certain fields because of THC in my system. The Prescription didn’t help me at all with that. Technically caffeine is a mind altering substance yet we allow high school students to guzzle it by the gallon if they want to. It’s all about the dosage. It’s still impossible to test inebriation with pot which is the kicker. >
  
  It isn't legal on a federal level. They have also mandated certain jobs can still test for safety reasons. You can choose a job that doesn't care. >
  
  This doesn’t really challenge my view. I stated that it’s legal in my state, which I believe should act within its own legislation, and not the federal governments. “Pick a job that doesn’t test” is a silly response. Safety reasons doesn’t hold, as it will detect marijuana I smoked 10 hours ago… doesn’t mean I’m under the influence on the clock >
  
  
  Safety reasons doesn’t hold, as it will detect marijuana I smoked 10 hours ago… doesn’t mean I’m under the influence on the clock
  
  That is precisely the problem: it would give even recent users "plausible deniability". If no employers were allowed to have rules against it, someone who is actually still under the influence on the job could just claim that they smoked/consumed it 10+ hours ago, and get away with it. 
  I agree for jobs where this is inconsequential, but for jobs where the safety of many is paramount, employers just cannot take that risk.