If anyone thinks that 'human grade' or just plain human food is safe, think again.

fda.gov alerts/recalls

USDA recalls

USDA recall list 2006

Just check to see how many human foods are listed for this year alone.

Unless a person raises their own grain, to feed their own cattle, and slaughters their own cattle, processes their own cattle, there is NO SUCH THING as perfectly safe anything in the food chain. And even if someone could feasably do all that, you still don't know what's in the air/soil/water you use to plant the grain in or the cattle grazes on.

It's impossible for every stage of food developement to test every batch for every possible contaminant there is. Assuming it could even be done the food would be so expensive that only the very rich could afford to actually eat.

The best you can do is stick with name brand products, handle/store/cook food properly and do not use any product that doesn't look/smell normal. Otherwise it's just hope for the best.