Opponents contend toxic substances would still escape into the air, and say they fear damage from accidents or violations.
Among those who have already balked at the proposal are the Burlington County freeholders in New Jersey, who passed a resolution asking Bristol Township to reject the project.
And Burlington City hired the law firm of former New Jersey Gov. Jim Florio to fight the burner.
"The fact is the winds blow from west to east, and that's not brain surgery," Florio said in an interview.
If the project receives final approval from state regulators - a years-long and unpredictable process - it would be Pennsylvania's first strictly commercial hazardous-waste incinerator, welcoming in trucks hauling drums of the material.
The last one to open in the United States was 20 years ago in Ohio, although another burner is under construction in the Southern United States, according to industry experts.
The proposal in Bristol Township has revived the debate over the need for commercial plants. Experts say commercial incineration could make a comeback because of growth in the petroleum and natural gas industries, which produce much of the nation's hazardous waste. But persuading regulators to issue a permit remains a challenge when alternatives exist for treatment and disposal.
"It doesn't mean a slew of new permits will be approved," said Barbara Noverini, an equity analyst with the investment research firm Morningstar.
State corporation records show King of Prussia-based Route 13 Bristol Partners formed last May. On Feb. 24, the firm will seek a variance from the township's zoning hearing board, the first of many steps. Final approval would come from the Pennsylvania Department of Environmental Protection.
Residents, town officials, and environmentalists from both sides of the river began fighting the project almost immediately.
"No matter what the regulations are, nobody can guarantee that dioxins and heavy metals and other toxic materials will not be part of the emissions from this facility," said Louis Cappelli Jr., a lawyer hired by Burlington City to fight the project.
Another opponent, Richard Heierling, 85, who lives in Croydon, said: "With any kind of industrial process, generally speaking, things run well. And when things don't run well, it could be a disaster. I understand that you've got to put things somewhere. But I'm not sure it's a good idea to put it in such a densely populated area."
The federal Environmental Protection Agency has determined that its standards for limiting emissions from hazardous incinerators are "generally protective of human health and the environment," the agency said in a statement. The agency is in the process of reexamining those rules, which could become more strict.
John Schert, executive director of the University of Florida's Hinkley Center for Solid and Hazardous Waste Management, said hazardous-waste incinerators are heavily regulated and generally have good compliance records.
"Their compliance record is a big deal to them," he said. "They want to stay in business."
Commercial incinerators proliferated in the 1980s after Washington passed several laws regulating the storage and disposal of hazardous waste, prompting as many as 100 to open up.
Since then, chemical companies began to change their operations to create less waste, or they built their own private incinerators. Tougher environmental laws made commercial endeavors more expensive. And states handed out fewer permits.
In the early 1990s, two companies applied for permits to build facilities in Pennsylvania, and each met resistance from citizens and the DEP. Both firms eventually gave up, citing economics.
One was proposed for Union County, in central Pennsylvania. Locals placed anti-incinerator signs along the highways.
The other incinerator was proposed for Clarion County, near Pittsburgh, by Conrail and an Ohio-based company. Protestors burned state and company officials in effigy.
Nationwide, the last one to be built was in East Liverpool, Ohio, near the Pennsylvania border, in the early 1990s, according to Mel Keener, executive director for the Coalition for Responsible Waste Incineration, a trade group. That project drew protests and opposition from then-Vice President Al Gore.
Eight sites in the country now operate commercial hazardous-waste incinerators, most in the Midwest and South, according to EPA data.
The number could grow again, although several factors could affect the commercial viability of such a project, Keener said.
"The chemical industry is rebuilding, and you cannot produce something without producing waste," Keener said.
But he added: "There is a very high barrier to entry for anything new."