13. Blackout Curtains Treated with Arsenic
In an effort to keep pests at bay, some blackout curtains from earlier eras were treated with arsenic-based compounds. While effective at deterring moths and insects, these chemicals released toxic particles into the air and onto skin, posing a hidden threat to household members. The use of arsenic in textiles is now unthinkable, but it serves as a sobering example of how well-intentioned solutions sometimes introduced new, serious dangers.
