All the time, starting on day 1. Dont bother till youre sober.
To get your CDL requires drug testing within the first few days. After that, it's every year or two years, depending, on every medical certification renewal. However, you can be randomly drug tested at any time.
All the time, starting on d as y 1.
The 1st time yu start, and randomly.
As often as they want are feel they need to...
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