Reuse, or recycle?

Courtesy of Sorenson BioScience

In labs across the world, heaping piles of pipette tip boxes spill out of trashcans and onto the floor. A single lab can burn through hundreds of pipette tips in an hour, creating enormous waste. In an attempt to minimize the waste, Jonathan Trent's protein chemistry lab at NASA AMES reuses all of its micropipette tip boxes.

"I don't know why everyone doesn't just reuse their tip boxes," says Trent. "It's so easy, and usually much cheaper." It only takes about 90 minutes to run a set of thirty boxes through an autoclave. While each box must be refilled with new tips, these are inexpensive when purchased in bulk. According to Trent's lab manager Suzanne Chan, the main cost is labor, and even this can be curbed by delegating it to interns or unlucky graduate students. This leaves Trent's garbage cans rather empty, as his bright blue and purple tip boxes are constantly in use.

Yet Trent may be more of an exception than a rule. A box of tips cost just one quarter of what it did eight years ago, and many researchers now opt for more convenient disposables. "Customer interviews indicate that people are throwing more and more boxes away," says John Brophy, Vice President of Marketing at the Salt Lake City-based Sorenson Biosciences. The tip manufacturer uses 80,000 pounds of plastic a month, and estimates the industry as a whole produces 4 million pounds of plastic tip boxes each ear. "We believe 70% of this ends up in landfills," says Brophy. It can take 200-400 years for typical plastics to degrade under standard conditions.

In response to this problem, a handful of companies have begun manufacturing more eco-friendly products. Sorenson began shipping the first paper boxes this summer. Made from sustainably grown trees, the boxes can be recycled along with cardboard and office paper. Since researchers exert 20 pounds per square inch (psi) of pressure when they connect their micropitter to a tip, Sorenson added a rubber stopper to the top rim of each tip, reducing the contact force to 2 psi, and preventing the boxes from collapsing.

While biodegradable tips have yet to be developed, in January, UK-based Anachem released a biodegradable box called EarthSaver; and Sonoma, California-based Labcon now sells the Eclipse - a tip tower with biodegradable components. "The corn resin facilitates naturally occurring bacterial and enzymatic processes," says Labcon president Jim Happ. "It's very durable, even though it will ultimately break under compost conditions." Both Labcon and Anachem's plastics can withstand the high pressure and temperatures of the autoclave, and can be reused.

These products may also contain fewer toxins than standard plastics. Long before Canada banned polycarbonate baby bottles for leaching bisphenol-A, researchers at Stanford University found the endocrine disruptor was impacting samples autoclaved in polycarbonate flasks (Environ Health Perspect, Suppl 7:129-33, 1995). The plastic additive nonylphenol can also leach from tissue culture bags and disrupt experiments (Environ Health Perspect, 92:167-73, 1991).

"You aren't likely to have this problem with bioplastics," says Happ. This is because the material is based on corn and other plant materials, and the manufacturing process doesn't involve as many harsh chemicals.

Yet reusing plastics may still be a better option. While biodegradable products are more likely to break down than are standard plastics, not all landfills offer ideal compost conditions. "In reality, even paper doesn't always degrade in the landfill," says Laura Sutherland, director of environmental purchasing at Practice Greenhealth, an Arlington, VA-based nonprofit. "If the choice is between biodegradable plastic items that can be composted, and non-biodegradable items that are reused, it may be better to go with reuse," says Sutherland. After several cycles of use, tip boxes can sometimes be sent to recycling facilities along with other plastics, she adds.

If demand continues, Sorenson plans to develop a paper-packaged product for robotic applications. Labcon and Amachem both say they are working on test tube racks, centrifuge holders, and other products based on biodegradable materials. "It's good that people are starting to think about waste reduction solutions," says Trent.