She wonders what she's breathing, though she says the odors are not as noxious as they were a few decades ago.

Since the terrorist attacks of Sept. 11, 2001, she also has wondered about security. A community activist, she toured the Conoco Phillips Bay View plant with a group of like-minded residents and was amazed at what she saw -- and didn't see. "There wasn't any guard or security official that I saw. There's more security at the airport than out here."

Now federal officials are catching up with Taylor's concerns.

In October, Congress passed a law giving the Homeland Security Department the authority to regulate the nation's most hazardous chemical plants.

Those rules have now been published, and regulators and the about-to-be regulated, congressional and state officials, industry and environmentalists all have different views of what comes next.

While New Jersey has a particularly large concentration of chemical facilities, nearly every U.S. urban area has plants that produce or use hazardous materials capable of endangering their neighbors.

California, for example, is home to 12 plants, each with more than a million people living in its shadow. Ohio has nine, Illinois 14 and Texas 17.

Homeland Security Secretary Michael Chertoff acknowledges "the collection of a lot of potentially dangerous chemicals in one place does create an attractive target to somebody who wants to carry out a terrorist attack."

Department regulators estimate as many as 66,000 plants around the country possess some amount of a "chemical of interest." Roughly one-third of those already are regulated by other agencies, such as the Coast Guard or the Environmental Protection Agency. For the rest, the government is asking the owners to complete an online questionnaire within 60 days telling what they manufacture, what chemicals they store, in what quantities and in what type of storage.

The department will determine their risk level by assessing the potential consequences to people nearby of an accident or attack, the impact of sabotage or theft, and the economic consequences of any catastrophe.

Chertoff estimates about 7,000 plants will fall into the high-risk category.

Assistant Secretary Robert Stephan, who will oversee the process, said 100 to 150 in the topmost tier can expect the earliest attention and closest scrutiny.

T. Ted Cromwell of the American Chemistry Council, an industry group, said some companies already have taken many of the required steps. But Stephan estimated 20 percent present a significant risk because they haven't participated in any voluntary program.