An effective drug testing program needs a drug testing policy. This may be part of the organization's drug-free workplace policy, or it may be a separate document. It should be distributed to all employees. The best protection against future legal challenges is to write a policy that is as detailed and specific as possible.
Some employers also test for alcohol.
While the overall drug-free workplace policy should apply to everyone in an organization, the drug testing policy may apply only to some employees. Therefore, the testing policy should clearly identify the employee positions included in the testing program. The policy should also indicate under what circumstances employees in each position will be tested. Employers whose employees are members of a union or collective bargaining unit should know that unless drug testing is required by law or regulation, it will likely be a mandatory subject of bargaining. The Consequences of Testing Positive or Refusing To Take a Test.