Is it a medical emergency if you swallow a splinter from treated wood?

So I’ve only posted twice on here now and they are both as opposite to each other as any post could get!

My Dad just rung me, he told me he’d swallowed a splinter in his workshop ( it flung into his coffee and he took a gulp) he said he couldn’t breathe and had a coughing fit that finally threw it up.

He told me that splinter was treated wood, arsenic etc etc and he said he was/is the sickest he’s ever been.

This was 4 days ago and of course he hasn’t and wont see a Dr, he’s told me he’s feeling better but how concerned should I be?

He lives alone, doesn’t look after himself, had 3 heart attacks before he finally took himself to the Dr – that kind of Dad….

Any thoughts?