Nitrite
From Conservapedia
Nitrite is an important polyatomic ion with chemical formula NO2-
Health
Nitrites are sometimes found if foods, despite the fact that they are harmful to the human body. A common source of nitrites in food is actually nitrates, which due to bacterial action or the digestive process loose one oxygen atom. Nitrates are found in a number of processed meats, such as ham and bacon.[1][2]