This Week's Giant Toxic Gas Cloud Over Houston Was a Symptom of a Much Bigger Problem

Yup, this happened.
Yup, this happened.
Photo: AP

Since Monday, Corey Williams has installed several air quality monitors in Houston-area schools. The state has nearly 40 that it owns littered around the city, but Williams, the policy and research director for Air Alliance Houston, a nonprofit environmental advocacy organization, doesn’t always trust the state, he told Earther.

And right now, the public’s safety is his priority: A cloud of black smoke hovered over the city for three days after eight tanks caught fire at a chemical storage facility in Deer Park, Houston, Sunday, for reasons that remain unknown. In the first 24 hours of the event, the plant billowed more than 9 million pounds of pollutants like carbon monoxide and nitrogen oxide into the air—more than what the city saw from Hurricane Harvey. While fire was finally put out Wednesday, on Thursday the Texas Commission on Environmental Quality (TCEQ) raised the alarm over “high levels” of benzene, a known carcinogen, resulting from vapors that started to escape from the facility once the fire was out.

Despite this, the state has been adamant that everything is fine. With regards to benzene levels which spiked to 190.68 parts per billion in a monitor near the facility today (the TCEQ marks 180 parts per billion as maximum safe exposure limit for a one-hour period), the state department wrote that “Levels at the maximum range detected could cause headaches and nausea, but it does not pose any lasting effects.”


Some residents don’t believe that, and neither do community advocates like Williams. This cloud looked big and bad, after all. And even as it dissipates, the communities in this area can’t escape the pollutants that leak out of industrial plants way too often, Williams said.

“This is a catastrophic emergency,” Williams told Earther of the recent chemical plant fire, “but they have a more chronic problem in some of these communities with exposure to industrial pollutants.”

The low-income and largely Latinx communities surrounding the plant, including Manchester, Harrisburg, Meadowbrook, and Allendale, see some of the highest cancer risks in the city from nearby pollution sources spewing cancer-causing ethylene oxide, according to the Environmental Protection Agency’s National Air Toxics Assessment. The Deer Park chemical storage facility alone has a history notable emissions eventsdefined as “unauthorized emissions of air contaminants from one or more emissions points at a regulated entity”—stretching back to 2003, with most years seeing at least three events.


The health of Manchester was the focus of a report the Union of Concerned Scientists released in 2016. Its residents face frequent exposure to toxins like xylene, toluene, and styrene, all of which make a person feel like shit and can cause long-term effects at high exposure levels, per the report.

A glimpse of what the apocalypse may look like.
A glimpse of what the apocalypse may look like.
Photo: AP

“You have not just this fire, but a long series of major chemical accidents that increase air pollution, increase toxic fallout into soil and water, and just are a multiplier on the effects that people feel within the communities themselves,” said Andrew Rosenberg, the director for the union’s Center for Science and Democracy, to Earther.

The fact that the Trump administration has attempted to roll back protections to prevent the sort of mess that occurred at the Deer Park facility this week doesn’t help, either, Rosenberg said. In January 2017, former President Barack Obama finalized an updated Risk Management Program Rule to help prevent these types of accidents and improve emergency responses when they do happen. However, the EPA under President Trump was quick to delay the rule, just a few months after it finalized. A court reversed that move, but the agency is still proposing a replacement.


The Obama rule is currently in effect, but Rosenberg makes a good point: It’s “only as good as the monitoring and enforcement.” According to Texas-based advocacy group Environment Texas, less than 3 percent of emissions events resulted in any state action over the last seven years.

With the toxic gas cloud gone, nearby residents are once again leaving their homes and sending their students to school. But the lingering memory of it serves as a reminder that they do so against a backdrop of industrial pollution. 


We have reached out to the EPA and TCEQ and will update if we hear back.

Correction: Due to an editing error this article previously stated that benzene levels near the Deer Park chemical storage plant spiked to 190.68 parts per million on Thursday. They actually spiked to 190.68 parts per billion. The text has been updated accordingly.


Yessenia Funes is climate editor at Atmos Magazine. She loves Earther forever.

Share This Story

Get our newsletter


Dense non aqueous phase liquid

Here’s what the TCEQ link from above says:

Emergency crews working the extinguished fire site at Intercontinental Terminals Co. in Deer Park are addressing escaping vapors. Local governmental officials issued a shelter in place Thursday morning after TCEQ air monitors detected high levels of benzene. Residents should go to web pages by Deer Park and Harris County for the latest information concerning any health warnings, including the current shelter in place.

One-hour levels of benzene in Deer Park were measured at a maximum of 190.68 parts per billion at 4 a.m., dropping to 48.03 ppb at 5 a.m. and 8.12 ppb at 6 a.m. Short-term exposure to one-hour benzene concentrations above 180 ppb can be a cause for health concern. Elevated benzene concentrations of 165.17 ppb were also measured at the Lynchburg Ferry monitoring station at 9 p.m. Wednesday as winds shifted from north to south. Levels at the maximum range detected could cause headaches and nausea, but it does not pose any lasting effects.

There’s about 3 orders of magnitude difference between what TCEQ and Earther is reporting for local area receptors. TCEQ has ppb written above. Should it be ppb or ppm?

Here’s the racial makeup of Deer Park and Harris County:

Deer Park: 62% white, 32% hispanic, and 5% other

Harris county: 31% white, 41.4 hispanic, 19% black and 6% asian.

Immediate receptors are pretty white. Downwind receptors seem pretty diverse. What demographic condition triggers EJ?