When trying to reveal to the rest of the Bat-team that she suspects she's become Poison Ivy, she references "hold each other accountable" as rule number 1 of the Bat-team. As established in the episode Rule Number 1, "hold each other accountable" was rule number 2 of their agreement, not number 1.
Sticking a mask over the face with some glue is not science. perspiration, oil, so many things come out of skin of the entire body, and if the glue seals all that micro-pores on the face, it will harm the face and entire body. Pimples and acne form just because oil is not come out of face's skin's pores.