Is mdf a dangerous material to work with?

Some people who mill MDF report respiratory discomfort or distress. MDF is composed of very fine fibers and a binder, either of which can be a lung irritant. Manufacturers and users generally recommend wearing a respirator when working MDF with power tools. If you aren't putting fibers in the air, though, you don't necessarily need a respirator (such as when painting or postioning a panel).