A train leaking hydrochloric prompted the evacuation of 250 homes near Monument early this morning, but it is unlikely any residents were exposed to the chemical.

A vapor trail was spotted on a northbound train around 1 a.m. While officials say the leak is “contained,” they do not know how much hydrochloric acid leaked from the tanker, which can hold 25,000-30,000 gallons.

It is unlikely anyone was exposed to the hydrochloric acid because it was a slow leak in an open area, said Mary Hilko, a poison specialist at the Rocky Mountain Poison Center.

The center has not received any exposure calls concerning the leak, Hilko said.

“The concern would be inhaling any vapors,” Hilko said. “It would have an irritating effect on the mucus membranes in the respiratory passages like the nose through and lungs.”

There are standard operating procedures for responding to a hazardous material leak, Phil Champagne, spokesman for the Denver fire Department, said.

Crews immediately form a perimeter around the leak, mitigate the leak and check to see if anyone was exposed to the chemical.

The evacuation was likely proportional to the size of the leak and the concentration level of the chemical, Champagne said.

As a precaution, hazardous material crews may set up a decontamination zone where anyone who has been exposed to the material can be treated.

Once the leak is stopped a clean up crew then works to contain, transfer and remove the hazardous material.

Someone with minor exposure to hydrochloric acid could develop mild symptoms including a cough, difficulty breathing and chest pain, Hilko said.

Prolonged exposures could result in fluid building up in the lungs and chemical burns, Hilko said. these symptoms could develop as late as three days after the person is exposed.

Jordan Steffen: 303-954-1794 or