Microfibers that slough off so-called “machine washable” wool biodegrade three times faster in marine environments than those from untreated wool, a new study commissioned by Australia’s largest wool-grower trade group has found. To prevent felting and shrinkage, machine-washable wool is typically treated with chlorine and coated with Hercosett, a polyamide-epichlorohydrin resin that prevents the barbed…