Lead Paint
You won't find lead in your products today. Back in a boomer's childhood, lead paint was potentially lethal. It was found in every home, but no one had any idea how poisonous it was. The legal amount of lead is currently no more than 0.06% concentration, but that's a recent progression...
Unsupervised Children
Kids used to just roam around neighborhoods and local shops looking for something to take up their time. No parents were around, maybe a few friends if they were lucky. Kids today are always being monitored and watched, but this is something that millennials have been pushing for in the future.