Less than a week after a train carrying hazardous materials went off the tracks in northeastern Ohio, burst into flames and stoked fears of a “potential explosion,” authorities assured evacuated residents that it was safe to return to town.

Maura Todd was not convinced.

The headaches and nausea her family experienced at their house last weekend and the pungent odor that reminds her of a mixture of nail polish remover and burning tires told her otherwise, Todd said.

On Saturday, she was making plans to pack her bags and move away from East Palestine, Ohio, to Kentucky with her family and her three miniature Schnauzers — at least temporarily, Todd said.

“I’ve watched every news conference and I haven’t heard anything that makes me think that this is a data-driven decision,” Todd, 44, told The Washington Post. “We don’t feel like we have a whole lot of information.”

After the derailment, federal and local officials repeatedly told residents that the air quality was safe and that the water supply was untainted.

But more than a week after the Norfolk Southern train derailed — causing an explosion that sent flames into the air and a cloud of smoke across parts of the village, and leading authorities to release a toxic plume — residents told The Post that they had yet to see a full list of the chemicals that were aboard the train when it lost its course.

Without much information, residents and experts told The Post that they question whether it’s safe to return to their homes a week after contaminants flowed into local streams and spewed into the air. In some waterways, dead fish had been spotted, a state official confirmed at a news briefing, and residents returning to homes in a neighboring Pennsylvania town were advised by state officials to open their windows, turn on fans and wipe down all surfaces with diluted bleach.

“The biggest question remaining is what, if anything, is still being released from the site, first and foremost,” said Peter DeCarlo, an environmental health professor at Johns Hopkins University. “If there are still residual chemical emissions, then that still presents a danger for people in the area.”

It was 9 p.m. on Feb. 3 when 50 cars of a 141-car Norfolk Southern train derailed, igniting a large blaze near the hazardous chemicals that kept firefighters away for days. The derailment, which caused no injuries, probably was caused by mechanical issues on one of the rail car axles, the National Transportation Safety Board (NTSB) has said.

The incident caused further alarm nearly 48 hours after the crash, when changing conditions in a rail car caused authorities to warn of a possible “major explosion.” Officials on Monday conducted a “controlled release” of vinyl chloride to prevent a blast, and on Wednesday they allowed residents to return.

Some nights, resident Eric Whitining told The Post, the air smells like an “over-chlorinated swimming pool” and his eyes burn. He returned to his house the day authorities lifted the evacuation order. He can’t move his family of five out of their home, so he says he has no choice but to stay put and follow authorities’ instructions.

“For a small town, we have to trust them, because what else do we have to do?” Whitining said. “We have to trust that they are not lying to us.”

More than 1,000 people — residents, business owners, and anyone who may have been harmed by exposure — have been affected, estimated one of four lawsuits that Ohio and Pennsylvania residents have filed against Norfolk Southern.

That lawsuit, filed Wednesday by East Palestine residents Ray and Judith Hall, alleges that negligence by Norfolk Southern led to the derailment. Their lawsuit, which seeks money, medical monitoring and more, alleges that residents were exposed to toxic substances and fumes, incurred costs due to the evacuation and suffered “severe emotional distress” and anxiety.

Norfolk Southern spokesman Michael L. Pucci said the railroad was unable to comment on litigation.

Norfolk Southern set up a “family assistance center” and is reimbursing residents who’ve fled their homes, though Pucci declined to say how many people that has included or how long the help will continue.

The Environmental Protection Agency has said the main chemicals involved were vinyl chloride, its byproducts phosgene and hydrogen chloride, butyl acrylate and others. But neither the EPA nor the NTSB has published a complete list of what the train was carrying.

Asked whether Norfolk Southern would release the list, Pucci referred The Post to the NTSB, which is investigating the derailment.

An NTSB spokesperson said the list would be part of the agency’s docket on the derailment, which is usually published months after an incident. EPA spokesperson Rachel Bassler said the agency had listed the chemicals that “represented the most acute impacts to the community.”

Some experts said that the EPA’s air monitoring should have been done with more sophisticated devices and that it was unclear whether the agency had enough data when it told residents the air was safe.

“In any of these situations, EPA is going to monitor with what tools they have available to them, but that doesn’t necessarily mean that’s the best way to monitor,” said DeCarlo of Johns Hopkins. “The handheld monitors that were being used are convenient to use, but they often do not have the necessary sensitivity or the chemical specificity to really assess whether there’s a risk.”

Judith Enck, a former EPA regional administrator, agreed. She said it was “unconscionable” that the EPA hadn’t publicly listed all the chemicals that were in the trains. The agency, she said, should launch a website that shows test results “in a way that is easy for the public to understand.”

“At a bare minimum, people should know what was on every train car,” Enck said. “This is a moment where you need maximum transparency.”

The EPA gave its air monitoring data to health agencies before allowing residents to come back, said Bassler, the agency’s spokesperson. Since the fire was put out, air monitoring has not detected concerning levels of hazardous chemicals, she said.

Nearly 450 homeowners have signed up to have the air in their homes screened, an option Norfolk Southern offered and the EPA is helping with. As of Friday night, 105 homes had been screened and no vinyl chloride or hydrogen chloride was detected in any of them, Bassler said.

Though vinyl chloride is a carcinogen, its worst effects have generally been documented after long-term or high-volume exposure, according to federal reports.

“Short-term exposure to low levels of substances associated with the derailment does not present a long-term health risk to residents,” Norfolk Southern said in an FAQ sheet for residents.

The question is whether enough contaminants were released to cause longer-term effects.

Nate Velez, 31, whose house and business sit near the train tracks, said his family isn’t planning on returning to their home. The house still smells of chemicals, and Velez said his wife, a nurse, “isn’t taking any chances” with the amount of toxic chemicals that were dispersed.

“The amount of . . . chemicals that were spilled and burned don’t simply just go away,” he said. “I don’t believe there is any way to know the full effect until enough time passes. And that just isn’t worth the risk.”

Todd and her family drove from East Palestine to Lexington, Ky., on Feb. 5 to shelter with family until authorities deemed the town safe enough for residents to return.

But when that happened, Todd said she would go check it out before considering moving back to the town.

So on Sunday, Todd and her husband, who spent the night at a hotel in Salem, Ohio, after returning from Kentucky, drove to her home in East Palestine, masks on their faces, to make an assessment. Her son and her three dogs stayed in Lexington, Todd said.

“We are counting on our senses because [officials] are not telling us much,” Todd told The Post.