In the US, anything that touches food must be shown to be safe (under intended conditions of use) before it is legal to market. Therefore any commercial food package that you buy in the store has a reasonable certainty - based on available scientific knowledge - of causing no harm, provided you are using the packaging as intended.
Of course, if you are using a package not as intended (heating something in an oven that should be heated in a microwave, say) or are using a container not in which the food was originally purchased (using that container that you bought one of your kid's toys in), then you are on your own. Although my personal opinion is that most good quality food storage containers are probably OK to use under mild heating conditions (e.g., microwaving your lunch).