Since I'm not around too much I'm not sure if anyone has posted this link before but I found it interesting.
From their website:
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.
Please note that while this table attempts to provide a reasonably comprehensive and accurate look at the insecticides most commonly found in pet flea control products, it does not claim to be an exhaustive list of products nor should it be used as such. New products are introduced regularly and many companies make multiple products with different chemicals. Pet owners should take care to examine the active ingredients in all flea control products they buy.

