Changes from EPA Method 218.6 to 218.7 Yield Improved Detection Limits for Hexavalent Chromium

E-Separation Solutions

E-Separation Solutions-03-01-2012, Volume 0, Issue 0

Chromium is a naturally occurring metal that is widely used in steel making, plating, tanning, paints, dyes, and wood preservation. The most common environmental forms are trivalent Cr(III), hexavalent Cr(VI), and the metallic form Cr.

Chromium is a naturally occurring metal that is widely used in steel making, plating, tanning, paints, dyes, and wood preservation. The most common environmental forms are trivalent Cr(III), hexavalent Cr(VI), and the metallic form Cr. The trivalent form is a nutrient and sold as a nutritional supplement, while Cr(VI) is a highly toxic carcinogen and regulated by the US EPA in drinking water and certain waste waters.1, 2 Cr(VI) is also monitored in soils, sludges, sediments, concrete, and leather to prevent exposure. In the US, the Criteria for Maximum Concentration is 0.016 µg/L for surface waters. Many countries also have discharge regulations, including Argentina, Russia and Italy (0.2 mg/L); Brazil, Mexico and Poland (0.5 mg/L); and Hungary (0.1 mg/L). Some countries have set a range for their discharge limits depending on the type of water, such as Chile (0.05–0.2 mg/L) and Tunisia (0.01–0.5 mg/L).

Click here for the full article in The Column