The Environmental Protection Agency weakened a rule Thursday governing how companies store dangerous chemicals. The standards were enacted under President Barack Obama in the wake of a 2013 explosion in West, Tex., that killed 15 people, including 12 first responders.

Under the new standards, companies will not have to provide public access to information about what kinds of chemicals are stored on their sites. They also will not have to undertake several measures aimed at preventing accidents, such as analyzing safer technology and procedures, conducting a “root-cause analysis” after a major chemical release or obtaining a third-party audit when an accident has occurred.

In a statement, EPA Administrator Andrew Wheeler said the revised “Risk Management Program” rule addresses concerns raised by security experts, who feared that releasing the location of the country’s chemical stores could provide a road map for terrorists, as well as others. Wheeler’s predecessor at the EPA, Scott Pruitt, suspended the Obama-era rule in his first month on the job after chemical companies and refiners complained that the 2017 guidance imposed too much of a burden on them.

“Under the Trump Administration, EPA is listening to our first responders and homeland security experts,” Wheeler said. “Today’s final action addresses emergency responders’ long-standing concerns and maintains important public safety measures while saving Americans roughly $88 million per year.”

Michael P. Walls, vice president of regulatory and technical affairs at the American Chemistry Council, said in an email that his group commends the EPA for ensuring that the federal government’s Risk Management Program “continues to deliver solid results when it comes to regulating safety at chemical facilities.”

Federal regulators sought to tighten handling procedures for flammable and toxic chemicals after more than 80,000 pounds of ammonium nitrate stored at a fertilizer plan in the Central Texas town of West caught fire April 7, 2013, killing 15 people and injuring 160. Federal investigators concluded in 2016 that the company had stored the ammonium nitrate in an unsafe manner, though arson was the direct cause of the blaze.

In a document released by the EPA on Wednesday, the agency said one of the reasons it decided to revisit the standards, which apply to more than 12,000 facilities across the country, is that the 2013 fire “was caused by a criminal act (arson) rather than being the result of an accident.”

Mason G. Lindsay, who is the chair of the Calcasieu Parish Local Emergency Planning Committee, in Louisiana, said in a statement that the changes to the rule “will help us to collect emergency contacts, conduct drills, review plans and incidents.”

But environmental and public health groups said the changes would leave chemical and refining operations vulnerable to future accidents.

“Given the EPA is first and foremost a public health agency, it is unconscionable that the Trump administration would gut key protections for emergency responders and people living near facilities that handle potentially dangerous chemicals,” said Elena Craft, senior director of climate and health at the Environmental Defense Fund. “We need more-detailed emergency plans, increased transparency and safer technology. This action moves in the wrong direction when it’s clear that the cost of chemical disasters is far greater than keeping communities safe.”

Dangerous accidents continue to occur at U.S. chemical plants. Last week nearly 40 House Democrats wrote Wheeler and asked him to maintain the Obama-era rule, noting that 73 accidents and leaks have taken place since it was suspended.

Last year, a grand jury indicted Arkema North America and two of its executives for what federal officials called “recklessly” releasing a cloud of toxic chemicals during Hurricane Harvey in 2017. The company denied the allegations in a statement at the time, saying, “It is hard to believe anyone would seek to criminalize the way in which one facility was impacted by such a crushing natural disaster.”