As of February 3rd, immigration officers have been temporarily prohibited from using teargas or projectiles munitions at protesters outside the Immigration and Customs Enforcement building in Portland, Oregon.

A federal judge, Michael Simon, ordered federal officers to not use chemical or any kind of projectile munitions, unless the person they are being used on imposes physical harm onto another person.
The ruling was made in response to a lawsuit that was filed by the American Civil Liberties Union of Oregon on the behalf of protesters and freelance journalists who were covering demonstrations at the flashpoint ICE building in Portland.
Some defendants within the alleged lawsuit include the Department of Homeland Security and its head, Kristi Noem, along with President Trump.
According to a Newser article on the same topic, the suit argues that federal officers’ use of teargas and force are a result of retaliation against protesters that disobeys their First Amendment rights ( Newser Editors , Feb, 4, 26 ).

As written in a Newser article, Simon claims that officers are now limited from firing projectiles at a person’s head, neck, or torso “ unless the officer is legally justified in using deadly force against that person “ ( The Guardian , Feb, 3, 26 ).
The restraining order will be temporarily in effect for 14 days,
Additionally, other courts have also began to consider the issue of I.C.E agents’ use of chemical munitions against protesters, with areas in Chicago and Minnesota restricting the use of teargas and pepper balls unless necessary to prevent an immediate threat.