The NRDC has put together a site called Green Paws, which aims to teach you how to protect your pet without chemicals. When chemical control is necessary, choose a safer treatment and avoid the most toxic chemicals by selecting a product marked with a yellow paw. Flea and tick treatments may contain toxic chemicals that can poison pets and harm people. Even when applied as instructed on the box, these chemicals are not safe, either for pets or humans. To help you make safer choices, NRDC checked the listed ingredients of more than a hundred flea and tick products to report which chemicals they contain and the chemicals’ toxicity: whether they are linked to cancer, allergies and asthma or are suspected endocrine disruptors. Each product is categorized by its potential risk. Products that don’t contain the most harmful chemicals are marked with a yellow paw. Pregnant women and young children are particularly at risk and should try to avoid any products from the red or orange categories.