Because employees are hired and terminated “at-will” in North Carolina, an employer may terminate an employee for any reason that is not discriminatory under state or federal employment law.
If an employee appears to be unable to perform the job due to impairment (other than due to a disability requiring reasonable accommodations under the ADA), then you would be expected to take them off duty; for example, if the employee was engaged in illegal activity, such as selling drugs on premises, and this action was verified. That said, as with every negative employment action, the employer should document the incident and file the report with the manager’s signature and the signatures of witnesses, if appropriate (such as an act of violence).
If an employee smells of alcohol or marijuana on duty, the safest course of action is to privately confront the employee to voice your concern. Acting on suspicion or unverified information, even if the suspicion seems clearly supported, is risky. Implying the employee is intoxicated in front of other staff members and customers could expose your business to a defamation action. It also can breed mistrust of management, and few people like seeing their peers embarrassed or humiliated.