"In any case, the byproduct argument loses its punch when you consider the environmental impact of conventional leather production, which involves a mind-boggling mix of acids, salts, fungicides and bactericides - as well as chromium, sulphides and sulphates. The result is a huge amount of water use, chromium sludge, and solid and airborne chemical waste. The bulk of leather processing has been outsourced to developing countries, where, according to critics, it's difficult to monitor standards."