Frustration among Paulsboro residents boiled over Wednesday evening at a raucous town hall meeting.

Residents said officials' responses left them even more skeptical of the seemingly slow cleanup that has followed Friday's freight train derailment, which spewed hazardous vinyl chloride into the air.

The meeting seemed like a microcosm of what residents said has been days of inadequate information about the evacuation and cleanup efforts.

As Mayor W. Jeffery Hamilton and officials from the Coast Guard and state Department of Environmental Protection tried to address a packed auditorium at Nehaunsey Middle School in Gibbstown, their microphones stopped working, and residents barked out questions and rebuttals.

At one point, when a DEP spokesman said there was "virtually no trace" of vinyl chloride in the water of the Mantua Creek, into which four tanker cars fell and one breached, Tony Bennett, a displaced resident now living with relatives across town, shouted, "It's worse than what he's saying!"

The retort drew applause from the 300 people packed inside.

Some who have not been displaced asked why officials had not evacuated the entire town, saying they can smell the chemical and feel sick.

Evacuees had a different question: When could they return home?

"Who's the genius who set the perimeter?" asked Nakia Pratt, 36, who lives in Woodbury but whose family lives in Paulsboro.

In response to elevated levels of vinyl chloride in the area, officials expanded the evacuation zone Tuesday, adding the residents of 100 more houses to the 400 people who were told to move out earlier.

The Coast Guard, which is leading the cleanup operation, has said residents will not be allowed to return home or businesses to reopen until Sunday.

Michelle Carroll, 43, who lives six houses off Mantua Avenue, one of the boundaries of the evacuation zone, and has been allowed to remain, said she can see the tracks where the accident occurred through a window. She said she was concerned that the levels of vinyl chloride outside her house were dangerous.

When Coast Guard Capt. Kathy Moore's microphone went out as she tried to explain the cleanup process, a resident interjected, to shouts of "Yeah" from the audience: "How come you evacuated half the neighborhood and not the whole neighborhood?"

Moore said officials were waiting for levels of vinyl chloride in the air to return to zero before lifting the evacuation order.

Gov. Christie and the DEP are "closely watching" what is going on, and Lt. Gov. Kim Guadagno will visit Paulsboro shortly, DEP spokesman Larry Ragonese said.

Among those chafing at the restrictions and uncertainty was Seabron Grace, who for a while tried to defy orders to close his Incizions Unisex Salon on North Delaware Street.

Grace, 33, said he should have been able to operate his business, on a boundary of the initial evacuation zone, especially considering that a nearby drugstore was allowed to stay open.

Officials said the drugstore supplied essential medical supplies but haircuts were not a priority.

Grace said that when he opened Monday, police told him to close.

Grace again opened on Tuesday; some clients had job interviews and needed haircuts, he said. Customers came and went, Grace said, until police threatened to charge all of them with obstruction of justice.

Police Chief Chris Wachter said he told Grace he could file claims for lost income and lost wages. "We already knew we were going to be expanding the zone beyond where he was," Wachter said. "I kept pleading with him to understand."

Asked about the legal ground on which police forced the evacuations, Wachter cited a declaration of emergency but declined to give specifics.

Wachter noted that even he was working out of a different location.

And he said the drugstore, too, closed Tuesday night after authorities expanded the evacuation zone.

Contact Andrew Seidman at 856-779-3846, aseidman@phillynews.com or @AndrewSeidman on Twitter.