"Approximately 3.5 million tons of BPA are produced annually worldwide," said Kaleigh Reno, the University of Delaware graduate student who presented the report. BPA is the component that gives polycarbonate its strength. But it is also suspected of exerting, among other things, adverse estrogenic effects in humans.
In the search for a safer, more environmentally friendly alternative, Reno and her advisor, Richard Wool, Ph.D., turned to lignin. Lignin is a naturally occurring complex hydrocarbon, which, unlike the hydrocarbons derived from sugars, starches and cellulose, contains aromatic rings instead of long molecular chains.
Reno developed a process that converts lignin fragments into a compound called bisguaiacol-F (BGF), which has a similar shape to BPA. She and Wool predict it will act like BPA, as well. "We expect to show that BGF has BPA-like properties within a year," said Wool, with a product ready for the market two to five years later.
Reno is confident that BGF will be a safe stand-in for BPA. "We know the molecular structure of BPA plays a large role in disrupting our natural hormones, specifically estrogen," she said. "We used this knowledge in designing BGF such that it is incapable of interfering with hormones but retains the desirable thermal and mechanical properties of BPA." The researchers also used U.S. Environmental Protection Agency software to evaluate the molecule, determining it should be less toxic than BPA.
And because BGF is made from an existing waste product - as noted in the report, papermaking and other wood-pulping processes produce 70 million tons of lignin byproduct each year, 98 percent of which is incinerated to generate small amounts of energy - Reno believes it will be a viable alternative, both in economical and in environmental terms.