The Pasadena Refinery System plant released thousands of pounds of toxins the morning of November 3, during a seven-hour power outage.
The toxic release marks the latest event at the refinery, the same plant where a March explosion injured one worker.
Officials worry more about this refinery than others in the area, as it has a poor record of emissions.
A report filed online with the Texas Commission on Environmental Quality showed more than 6,000 pounds of almost a dozen contaminants released between 4 a.m. and 11 a.m. Thursday.
Of the toxins released, about 1,400 pounds of the acidic gas sulfur dioxide and about two tons of fine-particle soot may be of most concern.
The Pasadena Refinery System plant paid a $14,000 federal fine for an explosion in December 2011. A key federal operating permit lapsed in 2015, causing the plant to face a $7,000 fine in 2016.
The toxins were not expected to spread far, due to minimal wind gusts in the area at the time of the release.
The company is operated by Brazilian state oil and gas firm Petrobras.
Source: The Houston Chronicle “Thousands of pounds of toxins released from Pasadena plant” by Dylan Baddour, November 4, 2016