Nitrites and nitrates possess a unique position in human toxicology. They are both ubiquitous in the environment and can be formed from nitrogenous compounds. Water, vegetables and meat are important sources of nitrite exposure. Nitrites have several detrimental effects on health. The primary health concern regarding nitrate and nitrite exposure is the formation of methemoglobinemia. Baby food and infant formulas can be important sources of nitrite and infants younger than six months are the most susceptible population. Furthermore, nitrites react with primary, secondary, or tertiary amines in an acid medium and form nitrosamines many of which are known to cause cancer. Health care providers, governments and health authorities should be aware of the routes of nitrite exposure and must have knowledge to assess the hazards. This review will focus on the detrimental effects of nitrite exposure, the possible outcomes and standards put by regulatory authorities to prevent high nitrite exposure especially for susceptible populations.