Misleading Food Marketing Labels: “No Nitrates Or Nitrites Added” Although there are nitrates naturally occurring in foods such as spinach, as I explain in the video, the ADI that I mentioned is specifically for nitrates added to processed meats from “natural” sources, such as celery powder or from “synthetic” sources, including sodium nitrate (E251), sodium nitrite (E250), potassium nitrate (E252) and potassium nitrite (E249). Nitrosamines can form if you cook nitrates or nitrites at high heat