For the past 10 years, environmental engineers at the U.S. Army Aviation and Missile Command have been working to reduce and eliminate the use of hexavalent chromium in aviation maintenance.
Mark Feathers is the lead environmental engineer for the AMCOM’s G-4 Environmental Division and serves as the toxic metal reduction program manager. He is part of the team that works to identify environmental and occupational health requirements that impact Army personnel and aviation and missile maintenance and depot processes. Earlier this year, Feathers worked closely with AMCOM leadership, the AMCOM Safety Office and the U.S. Army Combat Capabilities Development Command Aviation & Missile Center to develop an aviation maintenance action message that requires all Army aviation units to cease the use of aviation primers containing hexavalent chromium while providing them with a safe, effective alternative at similar cost.
The Occupational Safety and Health Administration defines hexavalent chromium as one of the valence states of the element chromium. It is used as an anticorrosive agent in paints, primers and other surface coatings and is known to cause cancer.
Feathers’ efforts will result in enhanced sustainability of Army aviation maintenance processes while improving the safety of Army employees by reducing their exposure to hexavalent chromium.
“First of all, let me say it's not just me, it's a team. We have a team of individuals, not only at AMCOM but across the Army and at the [DEVCOM] Army Research Lab. We have teammates at DEVCOM AvMC and other locations that work together because it doesn't make sense for us to work this in a vacuum,” said Feathers. “As a team, we highlight what the issues are and we’re able to help solve them. This creates a better work environment for our employees and sustains our processes.”
In addition to reducing or eliminating the health hazards associated with the inhalation of hexavalent chromium, AMCOM also must consider obsolescence.
“We operate in a global environment. Europe and other locations have been addressing replacement processes for many years,” said Feathers. “In Europe, companies and their militaries are required to comply with a regulation called Registration, Evaluation, Authorisation and Restriction of Chemicals, which essentially, bans the use of hexavalent chromium with rare exceptions. Reduction in market demand for hexavalent chromium products reduces profitability and elimination of the product from the market. This could result in an obsolescence issue for the Army.”
AMCOM has two compliance strategies to mitigate the harmful effects of exposure to hexavalent chromium. First, industrial hygienists implement controls to reduce the levels of hexavalent chromium in the work place such as a vent hood that pulls fumes away from the work bench.
Additionally, the Environmental Protection Agency requires certain controls in areas like paint booths that remove and treat the air within the work area. There are also tools that vacuum dust containing hexavalent chromium.
The other compliance mitigation strategy is mandatory use of personal protective equipment such as respirators that prevent the inhalation of harmful toxins.
The preferred strategy for reducing exposure is to eliminate hexavalent chromium in the coating and process being used, according to Feathers.
“This is where our team comes in. We develop alternative technologies that do not use hexavalent chromium, thereby reducing risk,” said Feathers. “AMCOM G-4 and their team members like AMCOM Safety, AvMC, ARL and CCAD, have been able to replace many hexavalent chromium processes. Our goal is to totally eliminate hexavalent chromium by the early 2030s.”
AMCOM G-4 works closely with the Navy, Air Force and original equipment manufacturers to share data and allow these organizations to leverage results and apply them to their application at their own facilities.
Hexavalent chromium has been widely used for decades by the military and industries in the private sector. As the health risks associated with toxic metals became known, the U.S. Army began working to reduce and eventually eliminate their use and is currently establishing a policy to define compliance dates for eliminating hexavalent chromium in processes.
“Our ability to develop technology exceeds our ability to understand the implications that it has on the environment,” said Feathers. “PFOS/PFOA is a great example. It has a great use [extinguishing aircraft fires], and then a few years later we find out it has negative environmental impacts.
“We’re getting better because many agencies have a very strong tie with the Army Public Health Center, and any new alternative process is evaluated to ensure it’s better than what we were using and there are no negative impacts to the environment or human health.”
Feathers acknowledged the contributions of the team in G-4’s Technology Integration Branch for their support of this initiative. The branch operates under the supervision of Glenn Williams and is composed of Scott Howison, Nancy Lykins, Leslie Hasenbein, Sheree York, Zubin Dutia and Michael Johnson. He also recognized other members of the Army team, including participants from AvMC, ARL and Corpus Christi Army Depot, Texas.