As we work in teams, and very often at the bigger units the team will be different every time, some reliance is made on those around being able to detect abuse. The nature of the job dictates that with responsibilities being so high, something will be said to the right person if needed (and occasionally a refusal to work with said person). Perhaps the tests should be more regular and not just the urine test, however everything seems to be ok as the safety records still look good, a obvious indication.