Near Houston on Tuesday three large oil refineries and a chemical plant spewed toxic gases into surrounding neighborhoods when a power failure shut down process and control equipment. Local officials canceled school and warned residents to stay indoors. Emergency officials were not sure how much excess pollution the plants or what toxic chemicals were in the pollution released.

Had the refineries installed backup power supplies they could have prevented the pollution event. Because of a loophole in pollution control regulations, however, refineries and many other industries have little incentive to take such precautions.

A loophole in federal air toxics limits allows refineries and other plants to emit unlimited amounts of pollution without any consequence if they do so during a “malfunction.” The shutdown of process and control equipment that takes place during a power outage is often deemed a malfunction under the federal rules, even though they could be prevented by the installation of backup power systems.

“Many big polluters depend heavily on electrical power and when the power fails these plants shut down and cause thousands of people to be exposed to dangerous chemicals,” said Hilton Kelley, a Goldman Environmental Prize winner and clean air advocate in Houston. “It’s time for these industries to spend the extra bucks and install their own electrical backup system. They must do everything possible to protect public health and the environment.”

In a lawsuit brought by Earthjustice on behalf of Sierra Club, Environmental Integrity Project, Louisiana Environmental Action Network, Coalition for a Safe Environment and Friends of Hudson, a federal court of Appeals found the malfunction loophole to be unlawful in 2008.  Nonetheless, the federal government has still not taken any action to remove it from the regulations that govern toxic pollution from refineries.

“The toxic release in Texas City is a clear illustration of why the malfunction loophole is so dangerous,” said Jim Pew, an attorney with Earthjustice who handled the lawsuit. “Plants are never going to take the precautions necessary to prevent this kind of pollution event when they have a get-out-of-jail-free card that works every time it happens. EPA needs to get this unlawful loophole off the books so that the people who live in Texas City and other impacted communities get the protection that they need and Congress intended the Clean Air Act to provide.”

“Closing this loophole would help prevent these events, plain and simple,” said Matt Tejada, director of Air Alliance Houston. “In Texas we have residential areas right next to clusters of industrial facilities that spew tons and tons of chemicals and yet, we are trying to defend people’s health. The monitoring technology exists to solve all these problems and facilities must be mandated to utilize them.”

With more than 250 industrial sites, Texas is home to the nation’s largest number of refineries, chemical and petrochemical plants in the nation. The state is also one of a few that tracks pollutants released during startup, shutdown, and malfunction periods: according to state records, thirty facilities emitted more than forty-five million pounds of toxic chemicals in just one year during these off-the-books periods.