Apr 17 2009
Researchers at the University of Minnesota School of Public Health found most containers employed for storage and transportation of used fluorescent lamps to recycling centers do not provide necessary levels of protection against mercury vapors emitted from broken lamps.
The release of mercury vapors, which can be inhaled or absorbed through the skin, presents an environmental and occupational hazard for workers involved with handling and transport. Mercury is a toxic chemical that can lead to neurological damage. The results of the study were published in a recent issue of the Journal of the Air & Waste Management Association .
The study aimed to compare and understand which packaging configuration would reduce the amount of mercury vapor released. In 10 replicate experiments, researchers examined 5 different packages containing 40 broken, used, low mercury lamps and measured the airborne mercury concentration in a test chamber over a 6-hour interval. The configuration that contained mercury vapor below occupational exposure levels was a double-box configuration with a press-seal, plastic-foil laminate bag.
The Environmental Protection Agency (EPA) encourages recycling of fluorescent lamps and instructs that packaging protect against breakage. The rule, however, does not include specific restrictions against vapor release. In 2005, the EPA added a requirement mandating that packaging be designed to prevent mercury from escaping into the environment. While fluorescent lamps are not included in this rule, the new study points directly at the need for more stringent legislation regarding the release of mercury vapor.
"We found that mercury vapor from broken fluorescent bulbs easily penetrates cardboard boxes and plastic bags. Successful packaging needs to prevent cuts and tears from broken glass in addition to containing vapor. This explains why the design that included a vapor-proof bag sandwiched between two cardboard boxes was the most effective package," said Lisa Brosseau, Ph.D., associate professor of environmental health and safety and co-author of the study.
Energy efficient fluorescent lamps are becoming a popular choice for consumers as energy costs rise. In the U.S. alone, discarded broken fluorescent lamps release an estimated 1 ton of mercury into the air annually.
Tracy Glenz and Richard Hoffbeck from the University of Minnesota School of Public Health, Division of Environmental Health and Safety, also contributed to this research. The study was funded by VaporLok Products LLC, a manufacturer of mercury-containment packaging.