If i eat processed foods once or twice a week, am i receiving more than a safe dosage of chemical food additives?

Depends on view: Additives have been around since they realized it could extend the useful life of these products. The processed foods you by must be assembled, shipped, shelved and often stored in your home until use. It could be a simple bag of cookies or canned food. Although it is a cottage industry to decry "additives" and paint them as bad, most of it is supported by junk science. Eat what you wish.