Colorado health officials have taken a first step toward penalizing operators of the Suncor oil refinery north of Denver for polluting metro air with hydrogen cyanide, a toxic gas — and the state may toughen its overall enforcement.

No decision has been made on Suncor’s request for a permit adjustment to allow more hydrogen cyanide. Colorado Department of Public Health and the Environment director Jill Hunsaker Ryan on Sunday indicated her agency’s in no hurry to approve that.

“The department has not granted the refinery any change in its HCN (hydrogen cyanide) permit and no change is imminent,” Hunsaker Ryan said in an emailed response to Denver Post queries.

“More broadly, as a department, we are reviewing our enforcement policies and strategies to make sure we are maximizing compliance with new and amended regulations toward attaining ozone standards, reducing greenhouse gas emissions and protecting the public’s health,” Hunsaker Ryan said.

Gov. Jared Polis has prioritized improving air quality.

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CDPHE air pollution control officials last week issued Suncor a compliance advisory, a formal notice that under the state’s current approach initiates enforcement for emitting hydrogen cyanide at a level of 14.1 tons per year. That level of pollution, detected in a company test and reported to the CDPHE in July 2018, exceeded the existing permit that limits hydrogen cyanide pollution to a level of 12.8 tons a year.

Separately last week, Colorado air pollution control officials finalized a legal settlement agreement with Suncor for a previous air pollution violation in 2017. Suncor consented to a compliance order for the company to pay penalties of $26,800 for violations and $142,100 in “administrative” penalties.

Rather than pay the money, CDPHE agreed to let Suncor hire a group called Groundwork Denver to perform CDPHE-approved projects worth $113,680, state officials said. The projects are designed to increase energy efficiency for people in low-income housing and try to increase access to fresh local food.

The fines and projects were imposed under existing enforcement policies, Garry Kaufman, the air pollution control division director, said in a statement sent to the Post.

The household energy efficiency work “will immediately benefit residents near the refinery,” Kaufman said, calling it an important step in carrying out CDPHE’s commitment to “ensure environmental equity.”

Suncor has a history of violating Colorado’s pollution limits.

The Denver Post reported in May that the oil refinery north of Denver, which emits more than 800,000 tons of air pollution a year, broke a 12.8-ton limit for hydrogen cyanide, an invisible toxic gas. Neither Suncor nor state health officials alerted nearby residents or county emergency managers after the July test found elevated hydrogen cyanide emissions.

A byproduct of processing crude oil at the nation’s 135 refineries, hydrogen cyanide can be deadly. It is a colorless gas that smells faintly of almonds. In concentrated form, it’s what the Nazis used to exterminate prisoners in death camps during World War II and it has been used in the United States for death-penalty executions.

Exposure at high levels leads to rapid breathing, followed by convulsions, loss of consciousness and death, according to the federal Environmental Protection Agency. Low-level exposure causes trouble breathing, chest pain, vomiting, headaches and enlargement of the thyroid gland. Scientists don’t know about the cumulative impacts on people who inhale multiple pollutants.

In Denver, people in the lower-income neighborhoods of Globeville, Elyria and Swansea have suffered from asthma, cancer and heart-lung ailments — possibly related to air pollution.

The Suncor oil refinery ranks among the state’s largest polluters. It releases 886,000 tons of heat-trapping greenhouse gases annually, along with 24 tons of sulfur dioxide, 12.5 tons of hydrogen sulfide, 25 tons of ozone-forming volatile organic compounds, 4 tons of carbon monoxide, 49 tons of nitrogen oxide and 55 tons of particulates, state and federal data show.

Some pollutants are regulated but hydrogen cyanide is not. State health officials say specifying the gas in a permit gives some control.

Suncor has asked the CDPHE to raise its hydrogen-cyanide permit limit upward to 19.9 tons a year, giving a greater buffer.

No direct measuring of hydrogen cyanide or exposure studies have been done.

Health officials said that the hydrogen cyanide at current levels is safe.

“Even with the emissions violation, the levels of HCN (hydrogen cyanide) are well below levels that would effect human health and do not pose a health risk,” Hunsaker Ryan said.

“We take the emissions violation very seriously. It is why, in the absence of a federal standard, the department created the permit limit in the first place.”