slide 2 of 12. Skin The skin is the largest organ in the human body. Its main job is to maintain the body's temperature, which means that sweat is created to cool the body, and goosebumps or raised hair occur to trap heat in the body. Along with sweat glands, the skin contains oil glands.
...However, if I am wrong about that, the answer is that acetaminophen (and its metabolites) are identifiable for up to 48 hours after you took the pill. Less if you took tiny doses, but up to standard clinical doses (<8g), it's 48ish hours.
If you do not have liver problems, the adult maximum dose of acetaminophen is 4 grams per day (4000 milligrams). If you take more than the maximum daily amount, it may cause serious (possibly fatal) liver disease.