The limit is 4,000 mg; a poisons unit acts at 10,000 mg
A US label warns at 4,000 mg a day. Poisons services in Australia and New Zealand treat one 10,000 mg dose as warranting the full antidote course.
What the study found
From the label's warning to the poisons threshold is 2.5 times
The liver warning on a US acetaminophen label names 4,000 mg in 24 hours. Poisons services in Australia and New Zealand treat a single 10,000 mg ingestion as enough to warrant a full antidote course. People who reached liver failure had taken a median of 24,000 mg.
The caveat · Poisons line is set below harm
None of these three figures is the dose at which injury begins, and the 10,000 mg line is set deliberately below where harm is expected so that clinicians act early. That threshold is also 200 mg per kilogram of body weight wherever that comes to less, so it is lower for a smaller person. It is Australian and New Zealand guidance, and the United Kingdom and United States set their own numbers. The 24,000 mg median describes people who had already reached liver failure, not a dose at which anyone should expect to.