Facebook has started to reopen some moderation centers but the return to work will be voluntary for its content reviewers.
The social network made the decision to send its 35,000 moderators home in March to protect their security.
He told a committee of MPs that he was now reopening some offices, with plans for social removal and protective equipment.
It comes when the NSPCC warns that child abuse is on the rise in the blockade.
Earlier this month, Europol said it saw an increase in Internet use by those seeking material for child abuse.
In a Zoom video call with MPs from the Digital, Culture, Media and Sports committee, Facebook's UK public policy officer Richard Earley said that dealing with child abuse images remained one of Facebook's key objectives.
"This type of content and these types of reports are absolutely the most serious we have to deal with on Facebook and are our top priority," he said.
When Facebook closed its content review centers, it shifted responsibility for moderating child exploitation material to full-time employees. Earley told MEPs that "a large number of employees who aren't even working to review the content in their daily roles" volunteered to go one step further to help.
He also said that "most content reviewers are now able to work from home and review content that way."
But realizing that the "new normal" would have been here for a long time, the social network also decided to open some of its review centers and allow contractors to return.
"This is completely voluntary and will be accompanied by new measures to ensure their safety is protected, including the reduced capacity of buildings and also the possibility of having access to protective devices," he said.
So far, a limited number of reviewers have returned to work in offices in the Bay Area of San Francisco and Austin, Texas.
Employees will have to check the temperature at the beginning of the shift and the buildings will be thoroughly cleaned at the end of the shifts.
Those who choose to stay at home will do so on full pay, Facebook said.