What is the difference between fast food and home cooking in terms of food safety and why?

Fast food is a fast word, let's say washing vegetables, their own home at least two times to wash, rinse twice, fast food restaurants can only do wash once rinse once; and some dishes such as four seasonal beans are not washed at all, pinched into a broken rinse once in the pot (I personally witnessed). And wash the pot is not clean, after frying a dish at home to brush the pot once, fast food restaurants may not brush clean, or can not do. The other dishes are not always clean, not as hygienic as your own. Fast food is not expensive, and the cost of washing them more than once will increase, making less money, which the owner of the restaurant will not be happy about. This is probably the difference with home-made.