Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services now if the exposed person has:
Difficulty breathing, noisy breathing, or rapidly worsening throat swelling
Collapse, severe confusion, a seizure, or difficulty waking
Severe chest or abdominal pain
Vomiting blood or signs of shock
A significant eye injury with sudden loss of vision
In other countries, contact the local poison information service or emergency medical service.
And for anyone, someone who:
you believe has taken an overdose or swallowed something poisonous
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
2
Is any of this happening?
Be seen today
After swallowing oven cleaner, contact a poison centre immediately, even if there are no symptoms.
In the United States, Poison Control is available at 1-800-222-1222 .
Do not wait for a routine appointment.
Urgent medical assessment is also appropriate for persistent coughing or wheezing, severe or increasing pain, repeated vomiting, drooling, trouble swallowing, blistering skin, or eye pain or blurred vision after rinsing.
3
Does any of this apply?
Book an appointment
For routine follow-up after a treated exposure, arrange medical review if swallowing becomes harder over days or weeks, food begins to stick, weight is being lost, or earlier symptoms return.
Every sign above is quoted from the sofidex article on Oven cleaner poisoning. If you are not sure, err upward — it is always reasonable to be checked.