What happens to the spot-on pesticides applied to pets that inevitably wind up abrading off onto furniture?

Question

For pesticides such as Frontline, Advantage, etc. that are monthly spot-on applied to the animal, inevitably some abrasion onto furniture, clothing, and people is going to occur, but what becomes of the pesticide once it is disbured throughout the household this way? Does it ever simply dissipate into nothingness, or does it linger there for decades?

Ie. If a dog sits on the sofa, does this mean that the next several times I have contact with this piece of furniture, that I'm getting the pesticide on me?

Furthermore, as an extention of this question, do pesticides like Fipronil and Imadacloprid, which are what's used in these products, bioaccumulate in the body? Or instead, do they quickly get filtered out of your circulation by the livers and jettisoned out of you in your pee?

Basically, should I be worried about the pesticide when it gets on the furniture, or is it completely harmless to me?

Answer 1

Hmm, that's an interesting question and I think one still under debate as both fipronil and imidacloprid are fairly new pesticides (registered as of 1997 I think??). The big advantage we have over the pet (and the fleas that the pesticide is killing) is size. We're a h**l of a lot bigger and so it takes more to harm us. On the otherhand, having seen the process of pesticide registration by the US EPA, I don't think we know how harmful this stuff is... It's just a matter of not really looking at sub-lethal and chronic health effects. They tend to be more concerned with acute, short-term effects than the long-term stuff seems like... However, I doubt it is completely harmless as it is a neurotoxin, but it also might be something our bodies can deal with easily?? Who knows!? I use Frontline and just try not to think about it.

So, here are a couple of fact sheets about the pesticides and they have Lethal Dose 50s (LD50s) that tell you how much it takes to kill half a population. Again, this is more like an acute, short-term effect rather than one over a long period of time. Gosh, I wish I could be reassuring and say that we know more than we do, but I can't be :(.

http://npic.orst.edu/factsheets/fipronil...

http://npic.orst.edu/factsheets/imidaclo...