Pa. company works to make fireworks greener

Tonight, the fireworks arcing over Philadelphia Park will be a little bit greener.

The colors in the display will be as bright and varied as ever, but with less environmental impact. That's because Zambelli Fireworks Internationale, the company staging the show in Bensalem, is working to reduce - and eventually eliminate - the pollutant perchlorate from its fireworks.

Zambelli Fireworks, based in New Castle, Pa., is one of the largest pyrotechnics companies in the country. This year alone, it is staging more than 800 Independence Day shows, including one atop Mount Rushmore.

But the company's chairman, George R. Zambelli Jr., said, "Being the largest isn't the main point. We want to be the safest, the most creative, the most innovative, and on the cutting edge."

One way to keep on that edge is to cut out perchlorate. This oxidizing chemical releases oxygen and speeds combusion in fireworks and flares. But the smoke it produces can irritate lungs, and toxic residues can linger in water long after the Fourth of July's colorful sparkles have faded from the sky.

Smoke and ashes from spent fireworks shower perchlorate on surrounding land and water. Also, chemicals from "duds" can leach into groundwater.

Most commercial and professional fireworks contain perchlorate. If people ingest it - by, say, drinking contaminated water - it can prevent the thyroid from absorbing iodine, a necessary nutrient.

In one Oklahoma lake, perchlorate increased to 1,000 times background levels after a fireworks display, and took 10 weeks to return to normal. And after a Fourth of July show in Long Island, concentrations in rain spiked to 18 times their previous level.

Only recently have governments begun to look at perchlorate in fireworks as an environmental concern. The Pennsylvania and New Jersey Departments of Environmental Protection do not regulate fireworks. Zambelli said his company had never been required to comply with specific air or water quality regulations to get a permit in any state.

Nonetheless, for the last three years, the Zambelli company has been working with its manufacturers in China to make cleaner fireworks, reducing the amount of perchlorate in many conventional fireworks by up to 50 percent. The company has also developed a line of perchlorate-free shells, some of which will be featured in the Philadelphia show.

It turns out that silver and gold are the new green.

When the Zambelli company began experimenting with perchlorate-free pyrotechnic recipes, these colors were relatively easy to get right.

"When we switched to a different oxidizer, we didn't get those intense blues, reds, and greens. It's going to take some more development," Zambelli said.