EPA/Yoan Valat French workers gain ‘right to disconnect’ Study found that overuse of smartphones for work can lead to burnout.

A new law forcing French companies to give their workers the right to ignore their smartphones outside of work hours takes effect Sunday.

The measure — introduced as part of a controversial overhaul of the French labor code earlier this year that is the first of its kind in the world — will oblige companies that employ more than 50 people to negotiate a set of rights with their staff about when they have to work outside of contracted work hours.

In 2015, Labor Minister Myriam El Khomri commissioned a study that warned about the dangers of "info-obesity," suggesting that using a smartphone to check work emails at all hours of the day can cause burnout, sleeplessness and relationship problems.

The use of smartphones "challenges traditional forms of working," Thiébart Patrick Jeantet, a lawyer specializing in employment law told Libération. "The digital transformation directly affects elements of the employment contract, namely the place and time of work."

The new law has been welcomed by France's powerful trade unions, who have argued that the overuse of smartphones results in many people working more than the 35-hour weekly limit.

"There's a real expectation that companies will seize on the 'right to disconnect' as a protective measure," Xavier Zunigo, a French workplace expert told AFP. "At the same time, workers don't want to lose the autonomy and flexibility that digital devices give them."

If companies and their staff can't agree to a deal, then management will be obliged to produce a charter that would make explicit the demands placed on their workers out-of-hours.