[jmanela]

I guess more of an engineering concern would be when you turn the machine on, the blade will stay safely where it is supposed to be and not hurt the customer.

However, you can try to make something as safe as you possibly can, unfortunately no matter what someone will find someway to hurt themselves. For example, you can make a car as safe as possible. It may get the highest safety ratings in it's class, but if you drive it off of a cliff there really isn't much you can do about that.