I was worried about how safe is Termidor when my house was treated for termites. I did my research and all indications directed that it is safe for pets and children. Some articles indicate that fipronil, an ingredient in Termidor is dangerous, but there is no evidence found in any studies. Fipronil is even used on dogs and cats for flea control for many years as well.
When Termidor is applied, it is dilluted so that the fipronil is approximately 0.06%, which is really low. Also, Termidor doesn't leach through rainfall because of its bonding agent to soil. As a homeowner, I wouldn't worry too much about it. If you use your common sense and treat Termidor as just other chemicals around your house. Don't drink it or rub your skin on it, or don't even lick it :)
I want to point out few things about the studies that claim fipronil caused thyroid tumors in lab rats who were fed fipronil over an extended period of time. When you look at the actual studies, you will find that these rats were fed thousands of higher dosage compared to normal. For example, just recently, some study came up with that coloring in coke has caused cancer in rats, but when you actually look at the studies, they gave ridiculous amount of them over an extended period of time.
So as I said above, as a homeowner, I wouldn't worry too much about the safety of Termidor. But if I'm the person who uses Termidor on daily basis as part of my job, I'd take extra measures to protect myself from any possible harms. In fact, there are few reports that people who worked with Termidor are suffering with thyroid and respiratory problems.
Treat it carefully, just like we treat bleach and other harmful chemicals, and let Termidor do its work; killing termites.