Review on Heavy Metal Concentrations in Glass Beads for Use in Roadway Markings

Citing the findings from research sponsored by the New Jersey Department of Transportation and the American Glass Bead Manufacturers’ Association, the Fair Glass Bead Market Access Coalition renewed its support for regulatory efforts to determine appropriate heavy metal concentrations for arsenic, lead and antimony for glass beads used in pavement marking applications.

The American Association of State Highway and Transportation Officials (AASHTO) empaneled a task force in 2007 Chaired by New Jersey DOT Bureau of Materials Chief, Eileen Sheehy, to review the metals in glass issue. The just released New Jersey DOT sponsored research by Rowan University and the New Jersey Institute of Technology is a key step in that process. Dr. Adi Raut Desai, of the Texas Transportation Institute, presented his industry funded metals in glass research, at the 41st Annual meeting and Traffic Expo of the American Traffic Safety Services Association. Using glass beads provided by the American Glass Bead Manufacturer’s Association, Dr. Desai reported that he was able to create an environment in which the glass beads leached metals.

“Let the peer-review process begin,” said FGBMAC Chair, Joe Winters. “These two studies are the first of their kind in evaluating the leaching of glass beads used in industrial applications, like the glass beads used in roadway pavement markings.”

U.S. regulatory standards relative to lead, arsenic and antimony in glass are varied depending on how the product is to be used in the marketplace. The Consumer Products Safety Commission, for example, currently permits products designed or intended for children 12 years of age or younger, to contain up to 300 ppm lead. That standard for children's products will be lowered to 100 ppm on August 14, 2011, unless the Commission determines that it is not technologically feasible to have this lower limit or that the product is not accessible to a child (16 CFR Part 1500.88).

The Federal Highway Administration (FHWA) has initiated its own review and is sponsoring research to determine how the New Jersey study’s findings relate to how beads are used in pavement markings. Carl Andersen, Roadway Team Leader for the Federal Highway Administration’s (FHWA) Turner Fairbanks Research Center is leading the effort. “We are confident that AASHTO’s Subcommittee on Materials and the Federal Highway Administration’s efforts will result in standards that enhance voluntary industry efforts already underway,” said Winters. “This regulation may impact what types of recycled glass is available for use in asphalt, concrete and as backfill, so it is important that regulators get it right.”

According to Weissker Manufacturing’s (Palestine, TX) Tony Wade, “This issue will be closely monitored by global providers of glass beads such as Weissker. We manufacture beads here in Texas but we also import beads to maintain high quality and lower costs for our customers. We want to ensure that standards are uniformly applied throughout the country and in the best interest of the public. This is why we support a national standard developed by AASHTO or the Federal Highway Administration rather than a myriad of individual state standards.”


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