By Nancy DeMarco
Metalworking fluid manufacturers and marketers need to check with their steel drum suppliers, to be sure they are not using sodium nitrite as a final rinse to prevent rust. Nitrites in the rust inhibitor can react with secondary amines in metalworking fluids, forming carcinogenic nitrosamines.
At its Management Forum in San Diego earlier this month, the Independent Lubricant Manufacturers Association’s Safety, Health, Environmental and Regulatory Affairs Committee reminded all companies handling metalworking fluids that both new and reconditioned steel drums can contain nitrite residues if sodium nitrite is used as a final rust preventive flush.
ILMA has advised its members to contact their drum suppliers, to assure that drums destined to contain metalworking fluids have not been treated with sodium nitrite.
Paul Rankin, president of the Reusable Industrial Packaging Association in Rockville, Md., which represents drum reconditioners, told Lube Report, “Sodium nitrite is a standard rust inhibitor for both new and reconditioned drums. It has been used for decades and it works.” He emphasized that RIPA believes any residue would contain very low levels of nitrites.
John McQuaid, executive director of the Steel Shipping Container Institute in Arlington, Va., whose members are new drum manufacturers, said that some SSCI members use sodium nitrite as a rust inhibitor while others do not.
“In the steel container industry,” said McQuaid, “it is well known about nitrites forming nitrosamines when combined with amines, and what countermeasures to take to prevent that from happening.”
However, McQuaid continued, “One SSCI member commented that sodium nitrite is the rust inhibitor of choice.”
The U.S. metalworking fluid industry discontinued using sodium nitrite as a rust inhibitor in fluids themselves after the Environmental Protection Agency’s 1984 advisory on the formation of carcinogenic nitrosamines when nitrite reacts with secondary amines.
The resurgence of the issue has alarmed metalworking fluid manufacturers. “The industry is concerned about any doubts that can be raised about carcinogens and metalworking fluids,” one source told Lube Report. Fluid manufacturers continue to face numerous lawsuits, and “it’s undeniable that a secondary amine and nitrite are a problem.
“End users would be furious” to learn their fluids might contain detectable levels of nitrosamines, this source continued. “Check your drums.”