SAN FRANCISCO (CBS SF) — If you live or work in California, you probably spend time near one of the state’s 17 refineries, and you may have wondered what refining chemicals end up in the air you breathe.

Up until a couple days ago, it would have been hard to say.

But for the first time, California’s Environmental Protection Agency has released a draft report identifying 188 chemicals emitted from its refineries.

Dr. Karen Riveles, the lead author of the report, confirmed that no California agency has previously compiled and published a report on refinery emissions and human health effects.

The report — which was spurred by a 2012 fire at the Chevron Refinery in Richmond — was produced at the request of community members and is the result of a collaboration between the Office of Environmental Health Hazard Assessment, the California Air Resources Board and the Interagency Refinery Task Force.

During the Chevron Refinery fire, roughly 15,000 people sought medical treatment at nearby hospitals for breathing problems and other symptoms, according to the U.S. Chemical Safety Board. The board found that the section of pipe that failed was recommended for replacement in 2002, but was not replaced. It was recommended for inspection in 2009, but was not inspected.

“Many communities in the vicinity of major refineries live in fear of exposure to airborne pollutants during a major refinery incident, as well as during normal operations,” California Air Resources Board Executive Officer Richard Corey said.

The top ten toxic air contaminants routinely emitted from California refineries — which are located in the San Francisco Bay Area, Los Angeles area and the Central Valley — were: ammonia, formaldehyde, methanol, sulfuric acid, hydrogen sulfide, toluene, xylenes, benzene, hexane, and hydrogen chloride, according to the report.

The report also spells out the health effects associated with some of the most prevalent and toxic chemicals.

Flaring — when an open flame and sometimes smoke billows from a refinery chimney — is the most common source of the chemicals, the analysis found.

The report suggests that the following chemicals be routinely monitored by the state, due to their toxicity and the volume emitted: acetaldehyde, ammonia, benzene, 1,3-butadiene, cadmium, diethanolamine, formaldehyde, hydrogen sulfide, manganese, naphthalene, nickel, PAHs, PM, sulfur dioxide, sulfuric acid, and toluene.

University of California at Berkeley Professor William Nazaroff tried to provide perspective on some of the scarier sounding chemicals, such as formaldehyde, a carcinogen perhaps best known for its use in the preservation of dead bodies.

“Formaldehyde. A major source is the adhesive resin used in manufacturing plywood, particle board, and similar manufactured wood products,” Nazaroff explained. “Because much of this material is used indoors (for furniture and building construction), indoor formaldehyde concentrations are commonly much higher than outdoor levels.”

Nazaroff argues indoor exposure to a chemical such as formaldehyde may be far greater in people’s homes due to furniture and construction than that emitted from petroleum refineries.

Indeed, the authors of the report state that “The release of these chemicals from refineries does not necessarily mean that local communities face a significant health risk or substantial exposures, but it does increase the likelihood of exposure for nearby communities. Air monitoring of these chemicals may inform decisions that could reduce exposure.”

Cal EPA says meetings with stakeholders and the public will soon be scheduled to allow for comments and feedback on the report. A final report is expected in early 2018.

The California Air Resources Board and the California Air Pollution Control Officers Association, which represents all 35 of the state’s local air districts, also released a draft report this week recommending enhanced air monitoring systems inside refineries and in nearby communities, as well as adoption of real-time reporting technology and better public notification.

Identifying the chemicals emitted from California refineries and recommending ways to make refineries safer is part of how the state is responding to concerns raised by community members in the aftermath of the 2012 Chevron Refinery fire in Richmond.

By Hannah Albarazi – Follow her on Twitter: @hannahalbarazi.