Is Frontline toxic if ingested by dogs?

I have 2 dogs that love to play together. I'm afraid to apply frontline because they nip or play bite each other a lot especially in the shoulder blade or back area where frontline is supposed to be applied. They might ingest the frontline. Is frontline toxic in ingested by my dogs? And I might as well just ask if it is toxic to people also since my family (especially the kids) kiss the dogs alot and our faces often get buried in the dogs hair when we hug them.