What is the MCL for Nitrite?

The maximum contaminant level (MCL) for nitrite is established at 1.0 ppm (part per million). This standard is set to protect public health, particularly considering that nitrite can be harmful, especially to infants and pregnant women, leading to conditions such as methemoglobinemia, or "blue baby syndrome."

The MCL is determined based on toxicological data and risk assessments that consider the potential adverse health effects of nitrite ingestion over long periods. Setting the MCL at 1.0 ppm ensures that water systems maintain a safe level of nitrite, thereby minimizing health risks. This level is part of regulatory measures that ensure drinking water quality and safety for the community.

The other values listed, such as 0.1 ppm, 10 ppb (which equals 0.01 ppm), and 10 ppm, do not align with the established MCL due to not providing adequate protection based on health studies or being excessively high compared to the recognized safe levels.