It is often stated that boric acid has the same toxicity as ordinary table salt in humans, which can be a little misleading. To understand what this means, it is important to understand a little bit about toxicology. In the medical field an objects toxicity is usually described as an LD50 value.
Mozzarella is the main type of cheese that is used on most pizzas. There are many different kinds of Mozzarella. Try to find a store that carries whole milk mozzarella. This is a nice creamy flavored mozzarella. It makes an excellent pizza.
Pizza hut uses skim milk mozzarella on it's pizza, at least in the USA. Not sure what they use in other countries, but I would imagine it is still the same. Skim milk mozzarella is extremely stretchy, but loses a little on the flavor end. More expensive pizzerias normally spring for the full fat mozzarella cheese. Dominos uses a mix of cheese, made up of mozzarella, Pecarino, Parmesan, and asiago cheeses. I think in their most recent reboot they switched to part skim mozzarella but I am not one hundred percent on that.