Substance abuse impairs the senses and really implies a hazard. In the case of an employee use of psychoactive drugs, many companies have developed alcohol and drug use policies. With policies, it should be well communicated to all employees. A clear, well communicated drug and alcohol policy can be a valuable management tool when it is reasonably and consistently applied. Drug and alcohol policies should be documented to allow each employee to know the consequences.
All staff needs to be informed that signing a contract means subjectivity to company's needs.
This is the idea of what a supervisor can do to prevent problems with substance abuse in the workplace. With a clear set policy there is no excuse that an employee can use to avoid the rules. Privacy Protection and privacy deals with the idea of human rights. Privacy, in the sense of suspicious individuals, is declared as Civil Rights to an employee in the United States. Random drug testing is protected in our civil rights and is almost impossible to touch for a company's interest.