3M Co. has a new product to fight air pollution, and it's not a filter or industrial monitor. It's a granule used in roof shingles.

When the granules are exposed to ultraviolet sunlight, "radicals" are generated that then transform nitrogen oxide into a substance that washes away with rain instead of polluting the air, officials said.

The product falls under 3M's industrial mineral products unit and is aimed for use on residential homes. Commercial buildings for many years have had solutions such as solar-reflective granules and "green roofs," which grow grass or gardens on top of buildings to help with the environment.

Solutions for the residential side of the business have not been nearly as robust, 3M said.

The company is marketing its new product as residential asphalt shingles, which cover about 80 percent of U.S. home roofs.

The new smog-reducing "roofing granules are a first for residential asphalt shingles," said Frank Klink, 3M senior laboratory manager. "This smart solution for pollution mitigation can help communities toward their [nitrogen oxide] emission reduction efforts."

The new product adds to 3M's roofing might.

The company, which started making granules in the 1930s, is now one of the largest roof materials suppliers in the country with customers such as Owens Corning, Malarkey Roofing, Atlas Roofing and CertainTeed. Over the years, 3M has developed products with environmentally friendly elements such as heat reflective granules for "cool roofs" and coatings that fight roof algae.

Gayle Schueller, 3M's chief sustainability officer, expects demand for the smog-reducing granules will grow as cities continue to grow and environmental concerns continue to be front of mind.

"We expect there will be a lot of interest in this," she said.

For example, Los Angeles recently mandated all new home roofs be made with products that help the environment.

In June, Oregon-based Malarkey Roofing Products became the first shingle maker to blend and adhere 3M's anti-smog granules onto its shingles.

Every shingle leaving Malarkey's Los Angeles factory is now made with the new product. Malarkey's shingle plants in Portland, Ore., and Oklahoma City will follow soon. The company started in Los Angeles because of the new mandates.

Malarkey CEO Jim Fagan expects his new shingles will be popular elsewhere, too. Salt Lake City, Phoenix, San Antonio, and Austin, Texas, are all dealing with smog-related problems.

By January, all shingles shipped to Minneapolis will have the 3M granules as well, Fagan said.

The smog-reducing granules cost more than other varieties, he said.

To avoid consumer price shock, only 5 percent of each shingle has 3M's product. But that 5 percent was enough to provide "three trees' " worth of air pollution fighting might per roof.

"That three trees is what we wanted," Fagan said. "It's the simple concept that you can do little things to make a big change. How do you eat an elephant? One bite at a time."

Other shingle makers and the state of Minnesota say 3M has piqued their interest.

"This new technology from 3M is very interesting to us. It has the potential to be a differentiator in the market," said Matt Schroder, spokesman for Owens Corning Roofing, which has a shingle plant in Minneapolis. "As with any new technology, our team must first research how, when and where it could make sense for us to go to market."

According to San Francisco-based Grand View Research, asphalt/shingle roofing represents about 27 percent of the global $105 billion roofing materials market.

3M would not discuss revenue expectations for the new smog-resistant product.

Wayne Gjerde, a market development coordinator with the Minnesota Pollution Control Agency, said 3M could be onto something novel.

"Anything that can reduce smog containing material is a good thing. We would be positively in favor of that," Gjerde said.

To prove the smog-resistant technology actually works, 3M sent the new roof granules to Lawrence Berkeley National Laboratory, which evaluated the product using gasses in a reaction chamber. The nitrogen oxide concentrations were recorded in real timebefore, during and after being exposed to ultraviolet light.

"The testing validated the efficacy of 3M's photocatalytic materials in reducing smog and contributing towards air purification," Klink said.

Jonathan Parfrey, executive director of the nonprofit Climate Resolve, hailed 3M's efforts.

"We view smog-reducing technology [that is] embedded into mainstream roofing materials as a great step forward in addressing air quality and climate concerns," Parfrey said. "This is not a magic bullet on its own, but it is a very helpful bullet on the approach to controlling air pollution. So we are very excited about this solution. I could see 3M having a very robust market here in California. … If you look at the 10 most smoggy areas in the county, eight of them are in California," Parfrey said.

Dee DePass • 612-673-7725