I used to work in a company that supplied a few mental health hospitals, and it was an eye opener just how many things had to be taken into consideration to keep their patients safe. It's not easy, and I can see why that can's can be dangerous as they can be very sharp if you tear them into strips. It made me feel lucky that it wasn't my burden. I did one hospital some long necked, cemented smoke bins because one patient ate the butt's and was really ill, then the replacement were long necked but not weighted which wasn't an issue until someone got hit on the head with one. So we got the Weighted ones sent out. They did the trick, but there was always something, and no matter what contingencies you put in place, a patient in a manic state can be dangerous to themselves with anything that comes to hand. It's nobodies fault, and all you can do is to make everything as safe as possible before incidents happen.