It appears "pepper ball" gas was used and not "tear gas"
The U.S.Park Police, one of the law enforcement agencies involved with clearing the park on Monday, denied using tear gas. But the agency acknowledged using "pepper balls," another chemical irritant.
A pepper ball is a projectile that contains chemicals, like pepper spray, that would irritate the eyes and lungs. Such a combination with smoke canisters would create clouds of a chemical irritant that would cause tearing.
The Centers for Disease Control and Prevention suggests that "tear gas" and "riot control agents" are terms that can be used interchangeably. On its website, the agency also states that "pepper spray" is a "riot control agent."
https://www.usatoday.com/story/news/pol ... 128855001/