FILE - Portland Mayor Ted Wheeler Protest

Portland Mayor Ted Wheeler stands with protesters at a demonstration outside the Mark O. Hatfield federal courthouse in Portland, Oregon.

(The Center Square) – As wildfire smoke pollutes Oregon’s skies, Portland Mayor Ted Wheeler has banned Portland police from using CS tear gas after months-long calls by activists and his reelection opponent.

The ban is effective immediately, but does not restrict Portland police from using mace or pepper spray.

“During the last hundred days in Portland, Multnomah County and State Police have all relied on CS gas where there is a threat to life safety. We need something different,” Wheeler said in a statement. “We need it now.”

CS is a common tear gas used by law enforcement and takes its name after the first letters of Corson and Stoughton, the two scientists who invented it in 1928.

Little scientific research has been conducted on the impact tear gas has on human health and the environment. Tear gas was banned for use in warfare by the 1993 Chemical Weapon Convention.

Congress members representing Oregon have asked the U.S. Environmental Protection Agency and the Oregon Department of Environmental Quality to study the effects of tear gas, pepper spray, and other chemicals used by police on human health and the environment.

The decision follows months of outcry by activist groups and Wheeler’s colleagues on the city council who have pushed hard to ban the use of all tear gas.

Portland mayoral candidate Sarah Iannarone, who faces Wheeler in the general election on Nov. 3, has made calls to ban the use of tear gas since protests started at the end of May.

Black Lives Matter Portland activists have made the same calls while the Portland city leaders including City Commissioner Jo Ann Hardesty, have pushed hard for banning tear gas.

Hardesty clashed with Wheeler over the summer and continues to demand that control of the Portland Police Bureau be handed over to her.

A federal judge instituted a two-week ban on tear gas in June and Wheeler directed Portland police not to use tear gas for the weeks leading up to the formal ban on Thursday.

Portland police used tear gas as recently as last week, according to reports from Oregon Public Broadcasting and other videos posted to social media by witnesses, during protests at its East Precinct building.

Lawsuits have been mounting against Portland Police for alleged police brutality and seriously injuring demonstrators in addition to documenting protesters’ faces over livestreamed video.

In July, Wheeler himself was teargassed by federal agents while addressing protesters demonstrating against police brutality in front of the Mark O. Hatfield federal courthouse.

Wheeler once again condemned violence in the city while supporting protests following the deadly shooting of Patriot Prayer supporter Aaron Danielson last month during a downtown Trump rally.

“I call on everyone to step up and tamp down the violence,” Wheeler said in his statement. “I’m acting. It’s time for others to join me.”

In mid-August, Proud Boys and anti-fascist groups fought in front of Multnomah County Justice Center and drew no police presence. Wheeler has since taken incredible criticism from local, state and national figures for his handling of policing in the time since.

The Proud Boys have announced on social media that they plan on returning to the city to rally on Sept. 26.

Staff Reporter

Tim Gruver is a politics and public policy reporter. He is a University of Washington alum and the recipient of the 2017 Pioneer News Award for Reporting. His work has appeared in Politico, the Kitsap Daily News, and the Northwest Asian Weekly.