Wool

Generic wool is shorn from sheep, scoured to remove grease and dirt, and frequently given a superwash finish (a chlorine descaling bath plus a Hercosett polymer resin coat) and sometimes a moth-proofing insecticide treatment, both of which add chemicals to the fiber that touches your skin.

The belief that a wool allergy is universal is wrong. A 2017 Acta Dermato-Venereologica review found wool is not a true cutaneous allergen; the itch is non-immune irritant contact dermatitis from coarse fibers (roughly 30-to-32 microns and up) mechanically jabbing your skin's nerve endings. So broad-grade wool itches more than fine merino purely because of fiber diameter. The chemistry matters more than the protein: superwash leaves chlorinated residues and a nylon-based Hercosett resin film, and the superwash step generates toxic adsorbable organic halides (AOX). Many wools are also moth-proofed with the insecticide permethrin, which is locked inside the fiber and can be OEKO-TEX certified, though it remains a pesticide on a garment. Residual lanolin in modern scoured wool is very low (under 0.5 percent) and rarely the real culprit. Wool itself breathes and thermoregulates well.

Prefer untreated, non-superwash, moth-proof-free wool, choose finer micron grades for comfort, and look for OEKO-TEX STANDARD 100 plus Responsible Wool Standard (RWS) certification.

Sheep are ruminants that emit methane and need grazing land; RWS certification also addresses welfare practices like mulesing.