Burgerville says it's banning employees from wearing buttons with statements and any other non-work approved items on their uniforms after 10 workers at a Northeast Portland branch were sent home in August for wearing pro-immigration pins.

The fast-food business announced Thursday that it's updating its written uniform policy so it "represents our long-standing commitment to creating a universally welcoming and inclusive environment for our customers and employees alike," according to a statement from Burgerville Human Resources Director Liz Graham. The new policy goes into effect next Thursday and forbids items on workers' uniforms that have political and personal messages.

The 10 employees at the Northeast Glisan Street and 82nd Avenue Burgerville wore buttons that said, "No one is illegal," and called for the elimination of the U.S. Immigration and Customs Enforcement. The employees returned to work the next day, received back pay and continued to wear the buttons, the company and the Burgerville Workers Union said.

A union spokesman said he is still reviewing the company statement and declined to immediately provide a comment Thursday.

Graham said in her statement that the company already had a verbal policy forbidding employees from wearing personal buttons on uniforms. The updated policy is common among businesses that regularly deal with the general public, she said.

"We respect our employees' right to express their own opinions and we encourage them to stay active and engaged in forums outside the workplace," the statement said.

Workers at two of the burger chain's locations in Southeast Portland and Gladstone voted to form a federally recognized union in the spring. The company is in the midst of negotiating a contract with workers.

Shane Dixon Kavanaugh of The Oregonian/OregonLive staff contributed to this report.

-- Everton Bailey Jr.

ebailey@oregonian.com

503-221-8343; @EvertonBailey