Testing your employees and applicants purely based on your own whim is strictly illegal, even if you have reasonable doubt. Unfortunately, there are no laws that require adults to submit to mandatory drug tests. But some laws and regulations enable you to, within the boundaries of the law, request your employees to undergo a drug screen.
To do so, you must first establish a comprehensive written drug-free workplace policy, with all the necessary elements included. Those legal elements consist of a statement of purpose, implementation, definition of all terms, the definition of illicit substances, and your and your employee’s responsibilities.
Each and every applicant or employee must be issued a copy of the said drug-free policy for him or her to read, sign, and date. By signing that policy, the applicant and employee empower you to legally request mandatory drug testing, which is to be conducted by the state-approved laboratory.