Content moderators for YouTube have received legal warnings the job may negatively affect their mental health and cause post-traumatic stress disorder (PTSD), a new report from the Verge found.

Social media sites are increasingly informing employees of the negative effects of moderation jobs following several reports on harrowing working conditions, including long hours viewing violent and sexually exploitative content with little mental health support. Before accepting a job with Accenture, a subcontractor that works with several social media companies and manages some YouTube moderators at a Texas facility, employees had to sign a form titled “Acknowledgement”, the Verge reported.

It was introduced days after the Verge published a wide-reaching investigation into the epidemic of PTSD among workers at the facility and told workers they must acknowledge that “It is possible that reviewing such content may impact my mental health, and it could even lead to Post Traumatic Stress Disorder (PTSD).”

A spokesman for Accenture told the Guardian it has long required new employees to sign these kinds of documents. The latest contract was given to new employees and reissued to existing employees, but a spokesman there are “no consequences” for not signing the reissued document.

“The wellbeing of our people is a top priority,” the Accenture spokesman said. “We regularly update the information we give our people to ensure that they have a clear understanding of the work they do.”

The contract was not sent at the direction of YouTube’s parent company Google, a spokesman from YouTube told the Guardian, but was an Accenture employment document.

“Moderators do vital and necessary work to keep digital platforms safer for everyone,” the YouTube spokesman said. “We choose the companies we partner with carefully and require them to provide comprehensive resources to support moderators’ wellbeing and mental health.”

YouTube is not the only platform facing these workplace hazards. Many of the thousands of contract workers who moderate content for Facebook have reported harmful psychological effects from viewing graphic content on a daily basis, a September 2019 report from the Guardian found.

A Facebook spokesman told the Guardian it does not have a hand in such contracts distributed by Accenture, and that its partner contracts mandate only pay and benefits.

In February, the Verge published one of the first behind-the-scenes reports from a US Facebook contractor where employees reported “the conspiracy videos and memes that they see each day gradually led them to embrace fringe views”, and that a former moderator “now sleeps with a gun at his side”.

A Twitter spokesman told the Guardian that both full-time and contract Twitter employees receive information in their onboarding that acknowledges they may potentially come into contact with sensitive material.

“It’s the nature of the work we do to ensure healthy conversation on our service,” the spokesman said. He added that Twitter is “consistently incorporating technology and tools that limit or reduce our moderators’ exposure to sensitive content”.