Is 27% Hydrogen Peroxide really harmful to the teeth and pulp? Can it cause craze lines or worsen them?

Would I feel 27% Hydrogen Peroxide if it spilled directly onto my gums or lip area?

(When my dentist was carrying out in chair I accidently dribbled some of my saliva on to my lips, would this harm my lips as it might have touched the peroxide then feel onto my lips?)

Also I heard that Hydrogen peroxide has the toxic hydroxyl radical and I am wondering if this can get into your blood stream via your pulp in your teeth and produce free radical damage in your mouth area and promote cancer cells.

I know I am looking in to this but I am really worried, I may look a bit of a hypochondriac but I read that Hydrogen Peroxide is a weak cancer promoter and a lot of people in my family have died due to cancer illness, I feel now I have had in surgery teeth whitening I have promoted a carcinogen cascade of free radical damage that will keep multiplying and I will get oral cancer from this.

Thank you for your time

Sorry if this sounds over the top, but please can you answer my questions, thank you