What is the maximum contaminant level (MCL) for Nitrite?

• A. 0.5 Mg/L
• B. 1 Mg/L
• C. 4 Mg/L
• D. 10 Mg/L

Answer: (B)

The maximum contaminant level (MCL) for nitrite is set at 1 milligram per liter (Mg/L). This limit is established to protect public health from the potential harmful effects of nitrite, which can interfere with the oxygen-carrying capacity of blood, particularly in infants, leading to a condition known as methemoglobinemia or "blue baby syndrome." Regulatory agencies have determined that levels exceeding this threshold pose a significant risk, making it essential for water operators to monitor and maintain nitrite concentrations within safe limits. Keeping nitrite levels at or below 1 Mg/L ensures that drinking water is safe and does not present health hazards to consumers.