In the November 2012 elections, states such as Washington and Colorado passed laws legalizing recreational use of marijuana. There also is a growing number of states with medical marijuana laws.
The DOT has now issued a response to these laws, available here. In essence, the DOT says that state laws do not affect the federal agency's enforcement position:
We want to make it perfectly clear that the state initiatives will have no bearing on the Department of Transportation’s regulated drug testing program. The Department of Transportation’s Drug and Alcohol Testing Regulation – 49 CFR Part 40 – does not authorize the use of Schedule I drugs, including marijuana, for any reason.
Therefore, Medical Review Officers (MROs) will not verify a drug test as negative based upon learning that the employee used “recreational marijuana” when states have passed “recreational marijuana” initiatives.
We also firmly reiterate that an MRO will not verify a drug test negative based upon information that a physician recommended that the employee use “medical marijuana” when states have passed “medical marijuana” initiatives.
It is important to note that marijuana remains a drug listed in Schedule I of the Controlled Substances Act. It remains unacceptable for any safety‐sensitive employee subject to drug testing under the Department of Transportation’s drug testing regulations to use marijuana.
We want to assure the traveling public that our transportation system is the safest it can possibly be.