As smartphones and portable devices increasingly dominate our working lives, moves are afoot in France and Germany to prevent the little electronic miracle workers from encroaching on people's private lives as well.

For several years now, some of Germany's biggest companies have started waking up to the counterproductive effects of expecting executives to be reachable around the clock.

"Burnout" has become a buzzword in recent years as an explosion in the number of work-related psychological illnesses has forced companies to rethink the demands they make on employees.

The last three or four years have seen firms such as car giant Volkswagen install virtual dams to prevent the seemingly unstoppable deluge of work-related emails from reaching stressed employees at home.

"The more work encroaches on people's private lives, the more employees are likely to suffer from stress, burnout and an inability to switch off," the national institute for occupational safety and health, BAuA, found in a recent report.

Teleworking, or using IT or telecommunications to replace work-related travel or enable work outside the office, can be a valuable option for a company because it offers flexibility, said BAuA expert Frank Brenscheidt.

Leaving the office early to pick up children from school, and then finishing off the day's work at home may suit some working parents.

But if it brings with it a permanent increase in workload and extra hours, "it can make some employees ill," Brenscheidt said.

- Sick days on rise -

According to the BAuA's statistics, the number of sick days taken as a result of psychological problems has increased by more than 40 percent between 2008 and 2011.

German auto giant Volkswagen, at the behest of the mighty metalworkers' union IG Metall, has prescribed a daily rest period from work-related emails.

Its servers no longer forward emails to employees' work phones between 6:15 pm and 7:00 am.

Originally aimed at around 1,000 white-collar employees, the measure has since been widened to cover around 5,000 staff members -- out of a total domestic workforce of 255,000.

Rival car maker BMW has come up with a different approach.

"We are aware that a boundary needs to be drawn between work and private life. But we don't want rigid rules to negate the advantages of worker flexibility," said Jochen Frey, a spokesman for BMW's personnel department.

Since the beginning of this year, more than 30,000 employees can -- in consultation with their bosses -- carry out tasks offsite and outside normal working hours.

For example, an hour spent answering an email request can count as a hour's overtime.

"But that presupposes a certain degree of trust and dialogue between workers and their bosses," Frey admitted.

Last Christmas, Daimler, maker of Mercedes-Benz cars, launched an "absence assistant" to delete emails arriving in employees' in-trays while they are on holiday.

The sender of the email is alerted to the employee's absence and invited to contact a colleague instead.

In 2010, the management of Deutsche Telekom decided that employees were no longer expected to be reachable around the clock and France Telecom adopted a similar initiative that same year.

- Laid down by law? -

France recently introduced a "right to unplug" for workers in the technology and consultancy sectors, where there are no set working hours.

The law -- which sparked a lot of bemused coverage in the Anglo-Saxon media -- effectively obliges workers to hang up their phones and portable devices at the office door.

But Bernard Salengro, a member of the white-collar union CFE-CGC, was sceptical as to "whether, or how strictly it will be applied."

For IG Metall, Europe's biggest union, some of the measures already introduced do not go far enough and, it argues, enforceable legislation is required.

"With the increase in the use of electronic devices by employees, regulation is needed," said union official Christiane Benner.

IG Metall is discussing the issue with the German labour ministry, which itself introduced new guidelines banning its employees from being contacted in their free time unless absolutely justified by exceptional circumstances.

Nevertheless in Sweden there is scepticism that a law obliging employees to "unplug" their work-related devices is the right way forward.

Martin Wastfelt of the Unionen, Sweden's largest white-collar trade union, called for more pragmatism.

"It's more effective to appeal to reason and explain to companies that it is in their interests to safeguard the health of their employees," he said.