D.C .employers have found themselves on the front line when it comes to the new marijuana legalization law. If an employee shows up to work stoned, can they do anything about it and what unions have something to say on the matter?

Construction sites that operate heavy machinery may be one of the first ones to support a no-drug policy to all employees for the sake of safety. The FBI has also said on their registration site that if you have used pot in the last 3 years, you might as well not apply.

This week, another new law will come into effect preventing employers from performing drug tests on employees before offering someone a job, but wmployers will still have the right to test employees after the job is offered. They can then enforce their own drug policy accordingly. Federal employees, on the whole, are prohibited from smoking pot.

Some current court cases might shed a little light on this issue; one of these involves an employee from fired from a television company for smoking pot.  As long as marijuana remains a controlled substance from a federal perspective, employers can still dispute marijuana use with employees. And even after  marijuana is rescheduled, it will likely still be prohibited in some jobs involving heavy machine operation or safety.