Which set of instructions is more formal?

 - Wash hands, utensils, and work surfaces after touching raw meat or poultry.
 - If you're going to be touching raw meat or poultry, you'd better wash your hands, forks, knives, and cutting boards afterward.
The second set of instructions is more formal. It uses more impersonal language and a direct command (wash utensils). The other set of instructions uses more conversational language (if you're going to be touching, you'd better).