10.27.21 | 5 min read

Hexavalent vs. Trivalent Chrome Plating: What Manufacturers Need to Know

Hexavalent chrome is probably one of the most widely known finishing compounds in manufacturing. Chromium alloys have been popular in the automotive industry for everything from tubing to coating. Its near-ubiquity in the mid-20th century is due to its superior resistance to corrosion, heat, and weather. As such, it also shows up in paint pigments and inks or dyes to color fabrics and plastics. There are few manufacturing industries that haven’t used it as a key ingredient in parts production at some point. 

Despite its widespread use, its popularity is waning, mainly due to the adverse health impacts to workers and the community. As such, we’ve seen a trend from manufacturers that are changing product specifications to remove hexavalent chrome plating entirely from parts, opting to utilize more sustainable processes.

A Brief History of Hexavalent Chrome

Hexavalent, or “hex,” chrome, has been commonly used in industrial applications, including welding, electroplating, tanning, and a variety of metal processing and pigment production practices. Unfortunately, hex-chrome, in concentrated doses, can be toxic to humans when consumed in water and food. Fans of the film Erin Brockovitch may recall how her work exposed the link between unusual occurrences of certain illnesses in the community of Hinkley, California, and high levels of chromium in the drinking water. 

In 2009, regulators in California proposed that hexavalent chrome be limited to 0.06 parts per billion (ppb) in drinking water. The federal EPA has set limits to 100 parts per billion for total chromium in drinking water.

With increased regulatory oversight on hazardous substances here in the U.S., as well as Europe, more environmentally friendly and less toxic alternatives are being sought. 

Trivalent Chrome vs. Hexavalent Chrome

There’s no question that, despite those drawbacks, hex-chrome is still more commonly used for plating applications. However, more and more manufacturers are converting their plating lines from hex-chrome to trivalent, or “tri,” chrome. 

Tri-chrome is a reduced state of hexavalent chrome, and is far, far less toxic. Unlike hex-chrome, trivalent chrome can be diluted and removed from waste streams, lessening the likelihood of environmental pollution. The main advantage of tri-chrome is that, like its toxic cousin, it’s extremely durable, and can be used to create a variety of finishes. It’s also scratch and corrosion resistant and can be produced in a variety of shades and colors. Many automakers in the U.S. and other OEMs are generally making the switch. 

Tri-chrome requires a chemical process that can be more expensive than that of hex-chrome plating. It’s also not nearly as widespread, and it can be a challenge for OEMs to find the right partner that has the right level of experience, as well as the infrastructure, to spec and machine parts that are as durable and long-lasting. 

The tri-chrome plating process, despite its environmental advantages, is still not as widely adopted as hex-chrome. However, it offers better production rates, decreasing the amount of energy required for production. Generally, this means you can also save money and achieve similar outcomes when using tri-chrome. 

Consider, as well, that compliance costs for hexavalent chrome are increasing right along with regulatory concerns. Making that switch now could eventually save OEMs and parts makers more on the bottom line in the long run. 

Top Advantages of Trivalent Chrome Production

  • Produces fewer rejects, less spent on scrap 
  • Better production with less chemicals and energy
  • Decreased toxic fumes
  • Less waste and wastewater treatment expense
  • Lower costs associated with testing regulations

Trivalent Chrome Improves Worker Safety

In addition to exposing communities and waterways to dangerous contaminants, hex-chrome is also a danger to workers who handle the substance. Workers in numerous occupations could suffer from potential exposure to hex-chrome—such as welders or machinists performing other “hot work” tasks with stainless steel and other metal processes. 

Workers operating chrome baths or using pigments, sprays, and coatings with hex-chrome could ingest dangerous levels of chromium through the skin, airways, ear canals, and eyes. Per OSHA, hex-chrome could further cause adverse health effects, including:

  • Breathing conditions (asthma) and other respiratory irritation
  • Eye irritation 
  • Perforated ear drums 
  • Organ damage (liver, kidney)
  • Pulmonary congestion and edema
  • Severe allergic contact dermatitis and skin ulceration 

There can be serious costs and fines levied against employers that don’t adequately protect workers. For example, the U.S. Department of Labor imposed a $280,874 fine on a Pennsylvania-based company for “exposing workers to hexavalent chromium fumes and other safety hazards at the company’s shop.” 

Not only do steep fines and inspections hurt the bottom line, they damage a company’s reputation (to say nothing of the potential exposure legally from employees who were harmed). 

Making the Switch to Trivalent Chrome from Hexavalent Chrome Today

The European Union is set to phase out hex-chrome plating by the end of 2021. Both OSHA and the EPA are continually defining new codes that will make overcoming those regulatory hurdles all but impossible when it comes to using hex-chrome in industrial applications. 

Tri-chrome is hardly experimental; it’s been used for various external applications for over 30 years. The transition can be complicated, mainly because the trivalent process can vary quite a bit from application to application.

LMC Industries has the facilities and expertise you need to transition to tri-chrome. Contact us to learn more about how you can make the switch today.

Article | Equipment | Metals

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