Weed Vs Healthcare Facilities

Hello! I work for a memory care facility who's weed policy is very unclear and wonky. I work as a nurse and as a CNA before than. There have been multiple times where workers (CNAs, PCTs) have come in high after smoking weed. They smell like it, have delayed reaction time, impaired decision making, and can possibly cause respiratory distress in our residents, especially those with asthma, COPD, etc. When employees have been sent home for weed use by nurses, they end up having to get paid the full 8hrs and are not fired. My biggest gripe with this is that, in Illinois, businesses are allowed to have a drugfree work place. Considering this is a healthcare facility, I figured the rules wouldn't have so much grey area. I brought this up in a meeting and, essentially, my boss (administrator), told me that people have sued for being terminated due to weed use. This communicated to me that the only thing the company cares about is not getting sued rather than our residents, which are put at risk. Just for the record, I am not against weed use, I just think it is extremely wrong to smoke weed on the job especially in a medical facility where you are taking care of people who cannot take care of their selves.

I am essentially asking for legal advise on how to address this. Whether with our corporate body and/or board of directors. TIA!!!!