I guess the question is whether they can be fired for being high over the weekend, rather than on the job. I've heard THC sticks around in the bloodstream for weeks after it's smoked.
I know that THC can stick around awhile.
Sure, it gets dissolved into the tissues of the body.
But my point is, just try to explain that when a factory worker cuts his hand off, or injures another worker.
The fact that THC is absorbed into fat will not save your business when you get sued.
I agree that workers should be allowed to indulge, OFF the job.
But some people have taken the lax pot laws to excuse usage while on the clock.