When I was a kid no one worried about chemical or environmental issues. Here is a list of what I played with. Somehow, I managed to survive.
  1. Pure mercury!
    My dad would bring it home. I would make globules and move it around. It would magically break apart and then come back together. No hazmat suit needed
  2. Radium.
    I had a glow in the dark radium watch. Batteries not included.
  3. Doesn't Hungry Hungry Hippos make the cut?
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    Suggested by @evan
  4. Gilbert chemistry set
    This set contained radioactive material and other hazardous chemicals. No big deal. Those were the days when you hid under your desk to protect you from a nuclear blast.
  5. Spark guns, cork guns,Cap guns
    They could cause burns or take your eye out. And they often did.
  6. Bows and arrows
    My friend and I played with them in the street. He accidentally shot me in the jaw. When I got older, I grew a beard.
  7. Dry ice
    You could get nasty freezer burns.