BSE, or mad cow disease, is a progressive neurological disorder in cattle. And strong evidence indicates that BSE can be passed to humans. To date, 190 cases of its human variant, Creutzfeldt–Jakob disease, have been reported.
Most of the cows found to have BSE in the United States have not been destined for the human food chain. That’s good news for the carnivores among us. But vegetarians are not off the hook. Beef by-products are used in many other ways.
For example, plastic products, including many used in medical devices, employ derivatives of beef tallow as lubricants in the manufacturing process. These products, called stearates, comprise 100–200 ppm in raw polyethylene. They are inexpensive and work well.
But it’s difficult to know whether the prions that are thought to cause BSE are present in stearates. Prions are virtually indestructible, so normal sterilization methods won’t kill them.
Because of the risk of contamination, worldwide healthcare agencies recommend that plastics suppliers document that their products containing stearates do not come from countries known to have BSE-positive cows. This involves a lot of extra work on the part of the manufacturer. Further, it appears the number of BSE-safe countries is dwindling.
So why not just get rid of the risk altogether? Why not just find other materials to do the job? Some suppliers are doing just that.
Value Plastics (Fort Collins, CO) offers animal-free polypropylene and polycarbonate fittings and connectors. “Polypropylene is by far the most widely used resin for flexible tube fittings in the biopharmaceutical industry,” says Bruce Williams, the company’s CEO. “Our new animal-free polypropylene significantly reduces our customers’ BSE-related paperwork by completely eliminating the documentation requirement for fittings made with this material.”
Another company, TC Tech (Maple Plain, MN), certifies its products are animal-free.
It makes films used in the construction of bioprocess bag chambers as well as tubing, fittings, and connectors used with bags and for other fluid-transfer applications.
According to Thomas J. Murphy, PhD, and John K. Schmitz of STI Components Inc. (Raleigh, NC), substitutes for animal-based polymer additives are not hard to find. The challenges are in sourcing these materials and converting processing lines.
Those challenges are well worth pursuing. Value Plastics and TC Tech have the right idea in moving away from animal by-products. Today’s recommendation could become tomorrow’s regulation.