Local government food safety guidelines for storing foods (p26) which have already been cooked stipulate food internal temperature must be brought from above 140F (serving temperature) to 70F in less than 2 hours and from 70F to 40F in less than four hours.
Why then do the rules for defrosting (p23) (the reverse) say food should be at room temperature "for very short periods during preparation" and foods can only be defrosted in one of three ways: in refrigerator, under running water, or in the microwave provided there is no interruption in the cooking process (ie. partially in the microwave then cooked or all in microwave). If its just time and temperature, why is the cook trusted to watch the clock for cooling and not defrosting?
Previous posts have asked for guidelines and best practices; however, my question accepts the practical advise and hopes to discover the political (creating effective guidelines) and biological (does warming from 40F generate more/more harmful bacteria than cooling from >140F?) reasons. I have my own theories but what are yours?