Cotton vs Hemp

Most field pesticide residue degrades or washes out during processing, so it is the finishing chemistry on the finished garment you wear that matters most. Conventional cotton labeled wrinkle-free, easy care, or no-iron is frequently treated with formaldehyde-based durable-press resins, a recognized human carcinogen that off-gasses and is linked to contact dermatitis and skin irritation. Reactive and azo dyes can also leave residue that touches your skin all day. The upside: untreated cotton is genuinely breathable and lets air move against your skin, which is why it stays comfortable in heat.

The fiber itself sits well against skin. It is breathable and does not trap the chemical residues that irritate sensitive skin. Your real exposure comes later, from what gets added: azo dyes, which can release aromatic amines (cancer-linked breakdown chemicals) and trigger contact dermatitis, and formaldehyde-based resins used for wrinkle resistance, a known carcinogen that causes rashes on direct skin contact. The fiber being natural does not protect you. The finish does the damage, so a cheaply dyed hemp piece can carry the same load as any conventional fabric.