Workers at Philadelphia's Center City Whole Foods store voted on Monday to unionize, becoming the first local store in the chain owned by Amazon to formally organize under the United Food and Commercial Workers.

Whole Foods workers in Philadelphia became the first group to unionize under the grocery store chain. The vote came months after it filed to hold a union election in November.

Whole Foods workers at the Spring Garden store have expressed frustration about low pay and want better health-care benefits.