Is pork barbecue safe to eat after 16 hours at room temperature?

No, pork barbecue is not safe to eat after being left at room temperature for 16 hours. The USDA advises that perishable foods should not be left out for more than 2 hours, as bacteria can multiply rapidly in the "danger zone" between 40°F and 140°F. Consuming food that has been left out for too long can lead to foodborne illnesses. It's best to discard any pork barbecue left unrefrigerated for that duration.