I learned from an employee at a department store that it wasn’t uncommon for clothes to be permeated with formaldehyde. I guess it was for preservation purposes in far-away warehouses in third-world countries. She said always wash new clothes. This was 25 years ago, so I don’t know if this holds true.
Washing doesn’t help.
I was on a flight a few years back with a woman who imported leather jackets from (Pakistan?). She told me they either tanned or preserved the leather with gasoline. She said there was nothing she could do to get the smell out (not to mention the danger of shipping something like that).