Breathe by Sarah Crossan

Set in a future where the Earth's oxygen is nearly gone and controlled by a powerful corporation called Breathe. Society is segregated into the wealthy "Premiums" who can afford unlimited oxygen, and the struggling "Auxiliaries," who must ration it.

This book contains; alternate gender/sexual ideology (implied), coerced alcohol consumption, death, deception, physical assault, profanity (minor), stealing, sexual content/nudity (minor), toxic relationships and violence.