Acting Mayor Kim Janey on Tuesday snagged a key endorsement as 32BJ SEIU, which represents property service workers, threw its support to her. She might also get a super PAC from them, too.

The union represents 20,000 workers in Massachusetts, many of them immigrants and people of color who work inside commercial office buildings, biotechnology companies, higher education campuses and Logan Airport. GBH News first reported the endorsement.

“During her short time as acting Mayor, and throughout her career, Mayor Janey has shown that she stands for making impactful change, which is crucial during this moment of recovery, healing, and racial reckoning as we grapple with the devastating COVID-19 pandemic,” Roxana Rivera, vice president of 32BJ SEIU, said in a statement.

Rivera noted that Janey recently signed an executive order raising the wage of security officers and cleaners in Boston buildings to $20 an hour from $14.85.

Roughly 6,000 32BJ SEIU members live within the city of Boston. Another 5,000 work in the city, but live in nearby Chelsea, Lynn, Everett, and Revere.

In the 2013 mayoral preliminary, the union backed then-Councillor Felix G. Arroyo in the 12-person race, and Marty Walsh, the eventual winner, in the November final election.

The union indicated that it could start up its own super PAC, a spokesperson confirmed, in a move similar to that of the hospitality workers union, UNITE HERE Local 26. The hospitality workers union has also endorsed Janey and launched a super PAC.

Super PACs — typically powered by unions and wealthy donors as each group is able to drop tens of thousands of dollars into television advertising, mailers and canvassing efforts — are flocking to the first open race for mayor since 2013, as they did when Mayor Thomas Menino opted against seeking a sixth term that year.

Janey, the first Black woman to serve as the city’s chief executive, became acting mayor in March after Walsh left the chair for President Joe Biden’s administration.

Tuesday’s 32BJ SEIU endorsement of Janey came as part of a package: UFCW 1445, which represents Massachusetts workers in warehouses, supermarkets, food delivery, health care and the cannabis industry also announced its backing.

Janey has also pulled in formal endorsements from City Councillor Ricardo Arroyo and his father, who serves as Suffolk County’s register of probate.

The twin endorsements last Thursday from Councillor Arroyo and Felix D. Arroyo, the register of probate, came after South End state Rep. Jon Santiago, who would have become the first Latino mayor of Boston if he’d won, dropped out.