30mg per 100ml of blood is the max here in Blighty. If you're over that, the Polce take you away.
Drug & Alcohol tests are done after any Safety of the Line Incident, as well as randomly.
By comparison, road users get done for 80mg.
A/S - They fine you for missing stops ? Wow, that's terrible. Don't suppose they give you a bonus if you stop when you're not booked to ?
Cheers, BW.