Contaminant Guide

Arsenic
Maximum Contaminant Level (MCL) 0.010 mg/L
Potential Health Effects
(from ingestion of water)
Skin, nervous system toxicity
Potential Source of Contaminant Natural deposits, smelters, glass, electronics wastes, orchards
Applicable NSF/ANSI Standard(s) Standard 53
Standard 58
Standard 62
Water Treatment Technologies Certified by NSF for Reduction of this Contaminant Distillation
Filtration
Reverse Osmosis (50 ppb)
Reverse Osmosis (300 ppb)
Special Notes Arsenic can be found in water in two different forms:
  1. Pentavalent Arsenic (also known as Arsenic 5, Arsenic V, or Arsenate)
  2. Trivalent Arsenic (also known as Arsenic 3, Arsenic III, or Arsenite)
It is important for consumers to determine which type of arsenic is present in their water prior to selecting a water treatment device. Those individuals with pentavalent arsenic can select either reverse osmosis or distillation. Individuals with trivalent arsenic can select distillation, or consider adding chlorine to their water to convert the trivalent arsenic to pentavalent arsenic.

For additional information on arsenic, view the arsenic fact sheet.