A chemical spill in National City Thursday morning escalated into a tall gas cloud and forced evacuations of homes and businesses across two to four blocks.

Four schools were notified, and at least two had students remain indoors for three hours, until any danger had passed.

Hazardous materials experts found that the dispersed gas was not highly toxic, but could have been an “inhalation irritant,” a fire official said.


No injuries or symptoms were reported to authorities, National City fire Battalion Chief Sergio Mora said.

The spill of an industrial cleaning agent, intended for a water filtration plant, occurred at Prochem Specialty Products on East 18th Street about 8:30 a.m.

Mora said two batches of a mixture of chemicals were put into two 55-gallon plastic drums, which were outside the business, near an alley.

The chemicals burned through one of the barrels, but did not ignite into flames.


Employees used a fire extinguisher on it, but that accelerated the burning process and much of the liquid spilled onto the ground, said Frank Parra, emergency services director.

The chemical reaction formed a gas cloud that rose higher than nearby apartments, Parra said.

Mora said the company has used similar containers for the product for years without any problem. Workers were trying to figure out what went wrong.

“It could have been residue (of some other material) in the drum; it could have been improper mixing; it could have been a number of things,” Mora said.


The first fire engine crews to get there called for additional rigs and hazardous materials crews.

Police sent out an evacuation alert in a social media posting.

Thirty to 40 people along East 17th and 18th streets between National City Boulevard and B Avenue were evacuated. Evacuees were told to gather at Sweetwater High School’s old gym, but no one did, Mora said.

National City Middle School and Olivewood Elementary Schools had students stay indoors as a precaution.


Hazardous material crews donned protective gear to approach the barrel to try to determine what caused the chemical reaction. A private clean-up company was called in to remove the spilled mixture.

The area was considered safe, evacuation orders were lifted and the schools resumed normal activities about 11:30 a.m.