Good ones! Hadn't even begun to think about chemicals/drugs and the labor & delivery stuff...

Main thing I think of when I hear "Chemical Reactions" (other than your listed stuff) would be VIOLENT Chemical Reactions...

Things are gonna get volatile. That could mean relationships breaking apart, armed conflict (human on human and/or human on zombo), leaders/leadership styles butting heads. All kinds of opportunities for things to become combustible...

I do wonder how much Michael/Pegs relationship stuff will be in the next chapter because of the title.