Many employers have adopted a “zero tolerance” policy on alcohol and drug use in the workplace to prevent accidents and to punish any non-compliance. But recent case law highlights situations in which the “zero tolerance” principle may prove insufficient, with courts recognizing alcohol or drug dependency as a disability under human rights and freedoms legislation. This means employers are faced with a duty of reasonable accommodation. Employers should implement a policy on alcohol and drug use in the workplace that addresses employer accommodation and requires employees to disclose any alcohol or drug dependency before an incident occurs in order to be accommodated.