He gets a pass on CFCs. Lead, though... the acute toxicity of lead compounds was known at the time. Workers making tetraethyllead were frequently poisoned, often fatally.
Midgely absolutely knew of the risks of lead, or at least he should have -- he had to take a leave of absence from his work to recover from a case of lead poisoning, and so many workers in the plant that made tetraethyl lead (TEL) developed inexplicable odd behaviors from their own cases that locals referred to the plant as "the loony gas building."
Worse still, Midgely worked actively to cover the risks of lead up. He even held a press conference in 1924 where, to assure reporters that TEL was safe, he washed his hands in a bowl of the stuff (https://www.bbc.com/news/business-40593353)!
