Check out this article. Apparently this could be an issue in CO.

You have to sign up to view the whole article. I read the hard copy today. Interesting article to say the least.

Friday, January 22, 2010
Medical marijuana a dilemma for employers
Denver Business Journal - by Renee McGaw

When it comes to medical marijuana, Colorado employers are caught between conflicting laws.

The stateā??s medical marijuana amendment, passed by voters in 2000, says that employers donā??t have to accommodate medical marijuana use in the workplace.

But another Colorado law, enacted a few years ago to protect cigarette smokers, prohibits firing employees for engaging in legal activities during nonworking hours.

That suggests that people who smoke medical marijuana before arriving at work could be protected under state law, whether their employers like it or not. And with roughly 30,000 Coloradans now estimated to be qualified to use medical marijuana, employers are growing increasingly uneasy.
Medical marijuana a dilemma for employers - Denver Business Journal:
davo420 Reviewed by davo420 on . Question for people with office jobs I'm currently working as an engineer in Texas and considering moving to Colorado. I am just wondering, for all of you office workers, what type of job do you have and do they randomly drug test? I know I could pass the initial screening, but if I got my MMJ card, I couldn't pass random tests of course. Since their is no protection for employees who use MMJ, I'm just wondering what you office workers do considering how common it is to use random drug testing, especially for big companies. Rating: 5