More than 200 Facebook workers from around the world have accused the firm of forcing its content moderators back to the office despite the risks of contracting coronavirus.
The claims came in an open letter that said the firm was "needlessly risking" lives to maintain profits.
They called on Facebook to make changes to allow more remote work and offer other benefits, such as hazard pay.
Facebook said "a majority" of content reviewers are working from home.
"While we believe in having an open internal dialogue, these discussions need to be honest," a spokesperson for the company said.
"The majority of these 15,000 global content reviewers have been working from home and will continue to do so for the duration of the pandemic."