Imagine yourself a sea captain, sailing from port to port with cargos of food. Which ones are a risk?
So a cargo of pistachios seems harmless, doesn’t it? It’s totally not – they can suffocate you, set themselves on fire in two different ways and might, for bonus hazard points, explode.
Cashews? They’re covered in toxic irritant irushiol, which has to be burned off before they’re safe for consumption. That’s why you’ll never see cashews in-shell.
I learned both of these and more at the latest issue of The Whippet, which I recommend to you. S/he finds interesting stuff.