Choosing a leather sofa for your living room may seem like an eco-friendly choice -- leather is technically a natural material. But since a cow's natural skin isn't the shiny, deep brown or black you normally see in leather sofas, that means the leather has been treated, most likely with chromium. The chemical tans the leather a deeper color and treats it for wear and durability. The problem with chromium is that you can develop an allergy to it when you have leather-treated furnishings in your home. The eco-friendly alternative is to look for vegetable-dyed leather, which uses nonchemical ingredients to achieve the same look. The only caveat? You have to treat it with oils regularly to keep the leather supple and durable. If that sounds too cumbersome, skip leather and look for canvas or cotton instead.