When polychlorinated biphenyl (PCB) was classified as a hazardous material in 1979, manufacturers of fluorescent light ballasts turned to di (2-ethylhexyl) phthalate (DEHP) as a replacement. DEHP, however, has since been classified as a hazardous material, and its users must now find an en-vironmentally-safe yet cost-effective way to disposal of the material.
DEHP, a clear, odorless, synthetic compound, is often used as a plasticizer. By 1985, most manufacturers had stopped using DEHP in ballasts for 4-foot fixtures but continued to use it for most 8-foot and high intensity discharge fixtures until 1991.
Of the hundreds of millions of light ballasts currently operating, a recent report, First PCBs, Now DEHP Ballasts, suggests that units with 15 million pounds DEHP are still in use, compared to a-bout 40 million pounds of PCBs in light ballasts. In a 30-page report, authors from the FulCircle Ballast Recyclers, Bronx, N.Y., examine four disposal options for DEHP ballasts: sanitary landfilling or municipal incineration, hazardous waste landfilling, whole ballast incineration and ballast recycling and DEHP incineration.
Landfilling DEHP ballasts provides the least expensive option, although since the capsule containing liquid DEHP can rupture or rust, the DEHP could eventually leak out and contaminate the soil and groundwater.
Incinerating DEHP ballasts is also relatively inexpensive, but if the solid metal mass en-casing the chemical keeps the DEHP from burning completely, the ash and eventually the soil and groundwater could be-come contaminated.
Disposal at hazardous waste landfills is less expensive than the remaining two options and safer than routine landfilling or incineration. The waste generator may still have potential legal liability, ac-cording to the authors, if the site e-ventually required cleanup.
Whole DEHP ballast incineration requires sending the units to a hazardous waste or PCB incinerator for total destruction. Of the four options, this is the most expensive, according to the report.
With recycling and DEHP incineration, ballasts are disassembled and the small capacitors containing DEHP and asphalt potting ma-terial are segregated. The remaining metals, including copper, steel and aluminum, are reclaimed.
Once separated from the ballast, the DEHP capacitor and potting material can be destroyed with in-cineration or disposed in a secure hazardous waste landfill.
DEHP is regulated by the U.S. EPA, the Occupational Safety and Health Administration, the Food and Drug Administration and 12 state and city agencies. Superfund regulations list DEHP as a hazardous substance, but under the Resource Conservation and Recov-ery Act (RCRA) and the Toxic Sub-stance Control Act, the chemical is treated more leniently.
RCRA lists the material as a hazardous waste when it is discarded in its pure, unused form. For ex-ample, a drum of DEHP would be classified as a hazardous waste, but a spent ballast capacitor filled with the chemical would not.
Nearly half of Superfund sites are contaminated with DEHP; however, the degree of contamination is not known. To prevent further improper disposal of the chemical, EPA has established a reportable quantity of 100 pounds (approximately 1,600 light ballasts) under Super-fund regulations. At least 10 states and two cities have gone beyond federal government requirements for regulating DEHP in air and water.