by Gail P. Montany
Plant construction for New England Composites, a Quebec-based fiberglass manufacturing company, is still going forward in the St. Johnsbury-Lyndon Industrial Park, despite a challenge to its air quality permit by a group of residents in the Stark District area.
The material causing the most concern among those challenging NEC's a~ plication is styrene, a toxic chemical subject to reporting under the federal Emergency Planning and Community Right-to-know Act.
According to Brian Fitzgerald, project engineer at the Air Quality Division, styrene is one of the most-studied chemicals, as it is one of the most commonly used substances and has multiple applications. Studies, he said, show no cancer-causing effects and no effect on fetuses or the reproductive system. However, studies do suggest that long-term exposure can cause problems with the liver due to the way styrene is metabolized.
Styrene is passed off in vapor during the production process of forming fiberglass panels. These vapors are collected and discharged outside. Direct exposure to these vapors, as with any organically based compound, will depress the central nervous system, said Fitzgerald.
According to state air quality engineer John Perrault, styrene falls into Category II, which means it is a chemical that could potentially cause unnamed chronic health problems if exposure lasts a lifetime. Category I means known or suspected carcinogens; Category III means short-term irritants.
NEC has applied for permission to emit seven tons of styrene per year (exactly the amount of styrene EHV-Weidmann Industries of St. Johnsbury has been emitting each year).
Styrene is one of more than a thousand potentially toxic chemicals under Section 313 (chemicals under Section 302 are considered extremely toxic; styrene is not one of them).
Styrene is just one of three chemicals the plant has specified on its application to the Air Quality Division, said Perrault. NEC will also emit acetone (the stuff in fingernail polish remover) and benzylaldehyde. Both substances are classified in the same category with styrene, but are not on the federal government's 10-ton-per-year control requirement threshhold (controls for those chemicals kick in above 100 tons per year).
Perrault said the application for styrene emissions showed they would be well below the federal standards, and even below the more conservative "action level" standards for Vermont (which if triggered would impose the most stringent options). He cautioned that while NEC's air quality impact would be well within acceptable levels, if the company grows it could trigger threshhold standards.
The aforementioned emissions standards refer to those measured at the top of the stack, where the chemicals are dispersed by wind.
Mathematical models also exist which predict where the impact will occur, and how it will affect the air people actually breathe (called "ambient air"). An odor study - styrene emits a characteristic plastic odor to which humans are sensitive - of the ambient air showed NEC would emit less than one microgram per cubic meter per eight-hour shift in the area surrounding the St. Johnsbury-Lyndon Industrial Park, said Perrault. The state standard for styrene is 512 micrograms per cubic meter. Styrene has no standard for ambient air at the federal level.
"I assume the state has done its research, and as long as we stay within the limits, we're being good citizens," said Chris Robbins, president of EHVWeidmann, a company that uses styrene to glue pressboard together. Styrene, he said, is an expensive petroleum-based solvent and in the interest of saving money, the company has recently come up with ways to use less of it and thus reduce emissions.
Most people, said Fitzgerald, are concerned with styrene's effects in tandem with other chemicals. Fitzgerald said there is no mechanism in place to measure two or more compounds. "It's a shortcoming of our regulations; we freely admit that," he said.
Perreault said as low as EHV's styrene emissions are, they are considered one of the state's larger sources of the chemical, even if they are not a major source. The bottom line, he admitted, is that NEC added to EHV means more emissions for St. Johnsbury. Still unclear is what will happen if more companies come to town with their air quality applications in hand, asking to emit styrene or other potentially harmful chemicals.
"If that were the case, the state would have to develop a plan to reduce styrene emissions," said Fitzgerald. "Even if we did monitor the ambient air in St. Johnsbury, I would not suspect styrene emissions would be anywhere near the (triggering) standards."
"Many other states, even New Hampshire, have much more emissions than Vermont," said Perreault. "We should consider ourselves lucky, but that doesn't mean we shouldn't scrutinize new companies.