It’s no secret that for millions of Americans, work doesn’t end at the bounds of the office or the close of business hours.

Amelia, 24, works in development for an education nonprofit. On a recent day off, she was at a doctor appointment and planning to buy groceries. Then, she checked her email. A caterer for an upcoming fundraiser wanted to finalize a contract and get paid promptly. That left her with little choice but to head into the office and sort it out. “If I don’t do the work, it doesn’t get done,” she says. “And if it doesn’t get done, it reflects poorly on me.” (She declined to give her last name for professional reasons.)

New technologies -- first email, then smartphones, now messaging services like Slack -- have opened up unprecedented avenues of communication and lightning-speed access to workers.

It comes with some benefits: Most employees, according to a recent Pew survey, say they enjoy more flexible hours thanks to email, Internet and cell phones, and nearly a majority say it has boosted their productivity. On the other hand, the tools allow executives, managers and -- in some cases like Amelia’s -- third-party clients, to make demands that bosses of yesteryear typically postponed until the following morning or the next week. The trend is more than a decade in the making, but it's gotten to the point where federal regulators may need to do something about it.

In August, the Department of Labor says it will issue a “request for information” -- an early step in the federal rule-making process -- “on the use of technology, including portable electronic devices, by employees away from the workplace and outside of scheduled work hours.”

Department officials declined to say more, and there’s no guarantee the information request will translate into a proposed rule. Still, the baby step shows U.S. regulators’ growing interest in a labor issue of mounting public concern, especially in the industrialized West. In recent years, experts and labor advocates in GermanyFrance and the United Kingdom have all expressed interest in cracking down on the sort of unpaid or underpaid “after-hours” labor that email facilitates. The U.S. could be next.

It’s improbable that American regulators would follow a German proposal to ban employers from communicating with clocked-out workers. An eventual rule is more likely to tackle the question of compensation, says Jennifer Glass, a sociology professor at the University of Iowa, and co-author of a recent Bureau of Labor Statistics study on the challenges of telecommuting.

The sort of after-hours work that’s most common -- an IT specialist who checks her email during family dinner and steps away to send a presentation, or an event planner who gets a text and hops out of bed to send an important email -- is often unpaid. Managerial and professional employees are most likely to encounter this, says Glass.

It doesn't necessarily bother all of them. "It's part of the job," says Krystie Zerbo, 29, senior account executive at an insurance firm, of the extra 10 to 15 hours she spends telecommuting evey week. Late-night emails allow her to connect with overseas clients and do her job more effectively.

But for those on the lower scale of the pay grade, that uncompensated work may sting a bit more. And the government’s imminent expansion of overtime pay eligibility makes the issue even more pressing.

As it stands, the vast majority of salaried workers don’t even receive overtime in the first place, since they earn more than the $23,660 annual income threshold. But President Obama is soon expected to raise that limit -- it remains unclear by how much -- and extend overtime pay to millions. That means all those consultants, clerks and real estate brokers will get a raise for working more than 40 hours a week. But the rules come with a risk: Any extra work that’s initiated by text or email -- outside office doors -- may not count toward overtime.

Employers have already said the new rules may limit their ability to provide smartphones and laptops to workers. Marc Freedman, executive director of labor law policy at the U.S. Chamber of Commerce, says the Labor Department's foray into the issue could be a sign that regulators are listening to those concerns. At the same time, he fears regulators are considering asking employers to keep track of all that extra time spent on company phones and email systems.

"How do you do that?" Freedman says. "I don't even know what the mechanism for that would be." 

Can The Invisible Hand Sort It Out?

In Germany, private enterprise has taken initiative. Vacationing employees at automaker Daimler, for instance, can set their phones to “holiday mode." Incoming emails trigger auto-replies with contact details for other employees before the messages are automatically deleted. BMW, Volkswagen and Deutsche Telekom all have similar policies limiting work-related communication.

But Glass says it’s unlikely many American companies will follow suit. (A 2012 survey from the Society of Human Resource Management found only a fifth of employers have policies on communication outside of work hours.) In fact, she says, there’s competitive pressure to stick to a laissez-faire approach. If IBM, for instance, told managers not to send after-hours emails to its employees, that could benefit Hewlett-Packard, and vice versa. It’s up to the government to take a stand, Glass says. “That’s the whole point of regulation, to level the playing field.”

Apart from the obvious pay concerns, a pair of newly released studies show unofficial work from home may come with health risks.

A December 2014 study released in the peer-reviewed Chronobiology International found that employees contacted by their employer or who worked in their free time to meet demands in the last year were more likely to report at least one health problem -- ranging from the psychological to the gastrointestinal and cardiovascular -- than those who did not. “In order to minimize negative health effects,” researchers said, “availability requirements for employees outside their regular work hours should be minimized.”

In another recent study, occupational health psychologists Larissa Barber and Alecia Santuzzi coined the term “telepressure.” They define it as “the combination of a strong urge to be responsive to people at work through message-based [information and communications technologies] with a preoccupation with quick response times.”

Even when there isn't work, the possibility alone is disruptive. Tobin Dietrich, 36, works as a consultant at a legal services firm and when "the client asks for something, it has to get done." He says he puts in about 20 to 25 hours of extra work per week -- during the commute, at night and on the weekend. On Saturdays and Sundays, when he'd like to spend time with his wife and child, "it's hard to make any plans."

Unlike face-to-face communication, emails and electronic messaging systems don’t usually require immediate replies. But as the technologies become more prevalent at the workplace, communicating parties may feel obligated to provide instant responses. That pressure follows some employees home, affecting their sleep and general focus.

As the field remains free of regulation for now, it’s often up to employees to monitor themselves.

"You just have to know when to turn off," says Zerbo, the insurance account executive. Amelia, like millions of others, took a precautionary measure after seeing her boss hound a co-worker on his phone. "I purposefully haven't given out my cell."