Several resin producers now offer grades of plastics that are "animal free" in response to concerns about potential contamination from bovine spongiform encephalopathy (BSE), commonly known as mad-cow disease.
Fears about the neurological disease peaked in the United Kingdom in 1993 at almost 1,000 new cases per week. Since then, the numbers of BSE cases has dropped sharply; 14,562 cases in 1995, 1,443 in 2000, 225 in 2005 and 11 cases in 2010, according to the US Center for Disease Control.
However, the impact of the disease on the plastics industry seems to have been growing inversely to the actual incidence of the disease. Reasons include increasing focus on extractables in medical plastics, the minuscule role of cow derivatives in plastics, and lack of effective substitutes.
Value Plastics, a design and molding company located in Fort Collins, CO, says that demand for its animal-free plastics has grown significantly since they were first offered in 2006.
Recent connector interest
"Animal-free materials have become popular due to the issues around BSE," says Ravi Narayanan, new product development manager. "Our initial focus was targeted towards markets regulated by the FDA with requirements for reducing the perceived health risks of "mad cow" (BSE) disease including healthcare OEMs and food device manufacturers. However, it has been a trend for the past few years where many of our customers have requested animal derivative-free materials in our connectors."
Target products are typically bags, containers and associated connectors, sanitary fittings and bag ports.
The Value Plastics Web site lists resin manufacturers with information relative to the use and sources of animal derivatives::
- Flint Hills Resources P5M6K-080 polypropylene, (animal derivative free)
- DuPont Zytel 101 nylon (reference cites hydrolysis/hydrogenation process precluding BSE transmission),
- Basell Profax PD626 polypropylene resin (reference cites hydrolysis/hydrogenation process precluding BSE transmission),
- Bayer Makrolon 2558-550015 polycarbonate (reference cites solely US and Canadian sources),
- Arkema Kynar 1000 HD PVDF fluoropolymer (animal derivative free), and
- Dow Silastic Q7-4750 silicone elastomer (animal derivative free.
Historically, stearic acids used as lubricants in plastics were commonly derived from beef tallow. Even though their concentrations in plastic compounds have been small, efforts to develop alternatives intensified a few years ago. Vegetable fats, such as cocoa butter, can also be used as a feedstock. Stearic acid has also been used as a mold release aid.
"The vast majority of our primary materials are animal derivative-free and/or EMEA 410 compliant," says Narayanan.
There are some modest tradeoffs with the animal-free plastics.
Softness an issue
"Primarily, differences in processing and cost are where you see the trade-offs," says Narayanan. "We are also challenged with a few grades from a mechanical properties standpoint where the material is a bit softer and more pliable, but cost is probably the most common trade-off."
Costs for the animal-free certified grades, however, have dropped since they were first introduced as more producers entered the market.
Value Plastics has taken a leading role in designing products with materials that meet the stringent regulatory demands of the healthcare industry. "We are always on the lookout for materials that come with animal derivative-free certification," says Narayanan. "It definitely gets a preference over other resins all being considered equal. If there are trade-offs as mentioned before, then they are weighed against the industry and customer requirements and an appropriate decision is taken."