Our facility uses a production powder coating system that consists of a 3-stage wash process prior to applying and curing the powder on the substrate. Recently, during a routine check of the storage tanks for each stage of the wash, traces of cyanide beyond acceptable levels were detected. I am trying to back-track our processes to determine the origin of the cyanide contamination.
I have reviewed the MSDS sheets of all the chemicals and products we use for cleaning/treating the metal surfaces prior to paint and have not found anything that contains cyanide. So... I am now looking for other possible sources of cyanide finding its way into the wash tanks.
Here's a brief overview of the substrates we paint:
ASTM A1008 Cold rolled sheet.
ASTM A1011 CS Hot rolled pickled & oiled sheet
ASTM A36 angle and bar
Do any of these substrates pose the risk of cyanide contamination?
I wonder if any of these materials may have been processed with cyanide compounds prior to coming to your organization. For example there is a steel case hardening process "cyaniding" and perhaps the steel (A36) was not properly cleaned prior to your organization cleaning it.
Other processes that could be a challenge is "Brine Quenching" as well as cyanide based zincates used in the manufacturing of aluminum.
I think that phosphate conversion coatings (also called parkerizing) may use cyanide in the process.
Last edited by Kelly Bramble; 09-06-2014 at 09:08 AM.