Carcinogen Permanent press, stain-resistant, easy-care — they all mean the same chemical. What chemical is in them? Formaldehyde-based resins are applied to fabrics: bedsheets, clothing, curtains, upholstery to create "wrinkle-free," "permanent press," "stain-resistant," or "easy-care" finishes. The resin bonds to fibers and slowly off-gasses formaldehyde over the life of the product. Especially when new and when exposed to heat or moisture (like a hot dryer or a sweaty body against sheets). Why it matters Formaldehyde is classified as a human carcinogen by the International Agency for Research on Cancer. At lower exposure levels, the kind from treated fabric, not industrial exposure known to cause skin irritation, allergic contact dermatitis, and respiratory irritation. Especially in people with sensitive skin or asthma. Because these fabrics touch skin for hours (sheets) or all day (clothing), it's a chronic low-level exposure most people...