Public Health Agency of Canada Issues Non-Medical Mask Policy for All Essential Workers Crossing the Border Wednesday April 15, 2020 | Border & Customs, COVID-19, News Releases, Operations & Safety CTA was informed today by CBSA that the Public Health Agency of Canada (PHAC) is directing the agency, effective immediately, to implement a policy requiring all essential workers crossing the border to wear a non-medical mask or face covering and to provide drivers with a mask should they not have one.