It depends."Boxes are padded with cedar chips"
I thought cedar was bad for chickens. Is it just chicks that are vulnerable?
I have well aged Western cedar chips mixed in with other chips in my coop and run, no issue as they've lost all their aroma. My brooder is also 100% cedar and my coop has cedar trim. Having lots of ventilation plays a role too.
I would avoid using all cedar, fresh cedar, or Eastern Red cedar (which is highly aromatic) as a general rule.