It's all about volume, not the type of audio device. When I was a stupid teen, I'd crank the car stereo to the point where I couldn't hear a car horn or siren. Now I am constantly listening to podcasts while driving, but I turn my device to a reasonable volume and loosen my earbuds a bit to ensure I'm not fully blocking out outside noises. Not a safety issue at all.
Ehh, a lot of pet allergies don't cause a sudden, violent reaction. I'm allergic, and I always pet my son and DIL's cat a little with no problems, but it'd be a bad idea for me to live under the same roof with her.