Ask the Expert Question-and-Answer Archive (Wastewater Treatment)
by Mike McGinness, EcoShield Environmental Systems, Inc.
February, 2003Heavy Metals in Powder Coatings
Q. Does actual powder coating contain heavy metals, or does it depend on the application. Were aware that metal prep befor the actual powder coat may produce some metals from alkaline and phosphate baths. Thank you.
A. It depends on the powder coating being used. There was a recent article or warning in Products Finishing Magazine (less than 6 months ago I think, but I have not been able to find my copy of it yet) about a job shop coating company that was coating various parts with a powder coating that was manufactured in Spain. The MSDS used by the importer did not reveal any heavy metals in the powder coating, however, according to the article about an investigation by the local state environmental agency the powder has as much 20% lead, chromium, and or mercury in the formulas. To make matters worse some of the powder had been used on food grade products according to the article! From my own experience I know that barium sulfate is a common additive in many coatings including powder coatings. Since many MSDSs are not worth the paper they are written on (i.e. many ingredients are not always listed and / or they are called trade secrets), and since they are rarely questioned or policed, I would suggest that it be considered a "possible source" of heavy metals until proven otherwise with verifiable lab tests. The next question is whether to test the raw powder, cured powder or both?
