Brown researchers create mercury-absorbent container linings for broken CFLs

Brown University engineering students Love Sarin (left) and Brian Lee display a nanoselenium-enriched cloth that can capture mercury vapor from broken compact fluorescent lamps. Brown has applied for federal patents... Click here for more information.

PROVIDENCE, R.I. [Brown University] — With rising energy prices and greater concern over global warming, compact fluorescent lamps (CFLs) are having a successful run. Sales of the curlicue, energy-sipping bulbs, which previously had languished since they were introduced in the United States in 1979, reached nearly 300 million last year. Experts expect that figure to rise steeply by 2012, when a federal law requiring energy-efficient lighting goes into effect.

There's just one catch to this energy conservation story: Each CFL contains a small amount (3 to 5 milligrams) of mercury, a neurotoxin that can be released as vapor when a bulb is broken. The gas can pose a minor risk to certain groups, such as infants, small children and pregnant women. Mercury can escape from plastic bags containing discarded bulbs, which makes long-term storage, disposal or recycling tricky.

The obstacles have led to a debate over CFLs, illustrated by recent studies by the state of Maine and the nonprofit Mercury Policy Project over CFL use and safe levels of mercury in the bulbs. Now, a team of researchers at Brown University led by Robert Hurt, professor of engineering, and engineering student Natalie Johnson may have found a solution to the environmental conundrum.

The scientists, along with other Brown engineering students and Steven Hamburg, associate professor of environmental studies, have invented mercury-absorbent materials for commercial use. The team has created a prototype – a mercury-capturing lining attached to the inside of store-bought CFL packaging. The packaging can be placed over the area where a bulb has been broken to absorb the mercury vapor emanating from the spill, or it can capture the mercury of a bulb broken in the box.

The researchers also have created a specially designed lining for plastic bags that soaks up the mercury left over from the CFL shards that are thrown away.

The mercury-absorbent packaging and the lined plastic bags can be safely discarded and recycled, the researchers say, alleviating concerns about contamination or other unwanted environmental consequences.

"It's a complete management system to deal with a bulb broken in the home," says Hurt, director of Brown's Institute for Molecular and Nanoscale Innovation, which concentrates on the study and commercial application of nanotechnology.