problem. you could test for pot and it could be in the system for as long as 30 days because it s fat soluable. if my client smokes pot a week ago and shows up for work and is tested it will be positive even though they re not under the influence of that drug. you could sues those drug testings for improper means. why is it any different for booze? it s legal to drink but not good to be drunk at work. so there s no federal law that says drinking booze is illegal. how does that intersect now? you can test for alcohol but there must be reasonable suspicion for use. you re on to something that s very important about mayrijuana that s different from alcohol. you stop drinking and you re sober in four or five hours. you may have a bad hangover, but the alcohol pretty much is out of your system. with marijuana, it goes on for a lengthy period of time. different world in that respect.