The state of Guanajuato will file a complaint against the Pemex refinery in Salamanca after it emitted large plumes of yellow smoke Thursday morning, alarming residents. 

Shortly after 9 a.m., residents of the city’s Granjas and Belavista neighborhoods alerted authorities to the presence of the oddly-colored, dense smoke.

Police, environmental officials and Civil Protection went to the plant where personnel explained that an error in the start-up process had caused the release of steam mixed with diesel fuel. 

Residents were told by Civil Protection to close their doors and windows and avoid going outside for an hour in order to safeguard their health. Air quality was affected, but not enough to raise a health alert.

The refinery’s managers did not respond to inquiries about the nature of the smoke on Thursday, which frustrated environmental authorities. 

“There has been no response or direct communication from those responsible for the refinery, regarding its internal processes, [which] hinders the implementation of preventive actions by Civil Protection and the Ministry of Health,” said state Environment Minister María Isabel Ortiz Mantilla.

Ortiz noted that it was not an isolated event. Two similar emissions have occurred in the past week in at the refineries in Salamanca and Cadereyta, Nuevo León.

Ortiz announced that her ministry will work with refineries to improve communication and minimize risk to the public should another incident occur. 

Five of Mexico’s six Pemex refineries are among the 25 top polluters in the world for sulfur dioxide (SO2) emissions, according to monitoring by NASA satellites in 2018.

Refineries in Tula, Hidalgo, and Salina Cruz, Oaxaca, are ranked fourth and fifth place, whereas the Salamanca refinery came in at 19th place out of the world’s 700 oil refineries.

Source: El Universal (sp), Infobae (sp)