The word “lead” conjures visions of a skull and crossbones.
We avoid it at home. Yet, the hazardous metal is quite common in hospitals and doctors’ offices, where it protects patients and health care workers from another risk: stray radiation.
Radiation Protection Technologies, a division of Thogus Products in Avon Lake, is working to replace those bits of lead one part at a time using environmentally safe tungsten-filled polymers.
Think back to chemistry class. Tungsten is the W symbol on the periodic table of elements. The metal, which is similar to lead, is ground into dust and combined with various base resins. The compound is then formed into components and used in everything from X-ray machines to CT scanning devices.
Several global medical device manufacturers, including Philips Medical Systems and GE Healthcare, are now using the parts. So far, Thogus has converted more than 50 parts from lead to poly-tungsten. The products account for 15 to 20 percent of overall sales.
The company is now ahead of the curve, says Russ Wolff, (pictured at left) vice president of sales. “It’s given us something we do that’s not done by a lot of our competition,” he says.
With the possibility of stricter standards for lead and a growing inclination for environment-friendly manufacturing, more competition may be on the horizon.
The driving force behind the conversion to poly-tungsten is a European directive known as RoHS.
The European Union passed the Restriction of Hazardous Substances directive in 2003 and enacted it three years later.
RoHS restricts the use of six hazardous materials, including lead, in the manufacturing of various types of electronic and electrical equipment, everything from radios and computers to circuit boards and speakers.
Medical equipment is now exempt but under review. The rules could change as early as 2012.
If so, products manufactured in the United States and exported to Europe would need to comply with RoHS standards.
The Highland Heights medical imaging technology division of Philips Healthcare contacted Thogus about seven years ago in search of lead alternatives. Thogus worked with PolyOne of Avon Lake and SABIC, formerly GE Plastics, to develop custom compounds for various applications.
Lead, which costs about 50 cents to $1 a pound, has been used for ages because it gets the job done and it’s cheap, says Peter Kozelj, mechanical engineer for Philips’ CT division in Highland Heights.
Poly-tungsten, on the other hand, could cost $20 to $30 a pound. But that doesn’t mean using poly-tungsten instead of lead is always more expensive, Kozelj says. The material is more robust and resilient than lead, which he compares to the consistency of butter or cheese.
Because it’s stronger, poly-tungsten can be molded into more complex shapes. And the manufacturer can reduce machining and assembly time. “This can easily make the cost difference negligible and even become a cost savings if engineered correctly,” Kozelj says.
The health benefits to workers, who have reduced lead exposure, are also important.
Plus, lead has other drawbacks, Kozelj says. It nicks easily, which can prevent a machine from taking crisp images.
All of the CT machines produced at the Highland Heights facility now include poly-tungsten material. Although the machines currently include about 20 to 30 pounds of lead and 5 to 6 pounds of poly-tungsten, the percentage of poly-tungsten will likely increase as designs are updated. By next year, the company plans to develop a fully green, lead-free CT scanner.
The majority of Radiation Protection Technology’s products are used in and on medical machines, but there’s potential for other uses as well, Wolff says. One customer uses poly-tungsten for counterweights in model cars.
And the company is working with a couple of customers to develop poly-tungsten cases for packing and shipping radioactive isotopes. The medicine, which helps doctors diagnose and treat tumors and cancer, is traditionally packaged and shipped to hospitals in lead vials.
“There’s a lot of opportunity for growth,” Wolff says.