Many American women do not yet know that the current US federal law states about what rights women have to pump their milk at work; and what accommodations they are entitled to get from their employers.

Tom Spiggle, author of “You’re Pregnant? You’re Fired!,” who focuses on pregnancy discrimination in the workplace, says that if you are breastfeeding your child, the right to pump milk at work under federal law remains a bit complicated. The Affordable Care Act of 2010, also known as Obamacare, requires employers to allow women to pump breast milk while they are at work, but like many federal regulations covering American workers, it’s shot through with loopholes.

“For the first time, women constitute more than half of the workforce and the fastest growing `segment is women with children under the age of three,” says Spiggle. “Although many workplaces now provide lactation rooms and staggered breaks for breastfeeding mothers, they’re often doing so voluntarily as a good business practice to help retain female employees and not as a matter of law. And a good business practice it is.”

Spiggle says the good news is if a woman is covered under the law, her employer must provide a “reasonable break time” to pump milk each time you need to during the day, which is typically every few hours. That includes any time she would need to retrieve and use any type of breast pump. She must also be given a private space that is not a bathroom where she won’t be bothered by coworkers or customers. (It doesn’t necessarily have to be a dedicated lactation room, however.)

The bad news is a woman’s breast-pumping time doesn’t have to be paid, unless her coworkers also get paid breaks. And not everyone is covered by the new law. For starters, employers only have to meet the requirement if they have 50 or more employees, but as it turns out, only three percent of America’s small businesses (defined as those with fewer than 500 workers) fit that definition in 2010. A company with fewer than 50 employees must comply with the law unless it can prove that it would be an “undue hardship” to do so. The Department of Labor has made it clear that this standard is a very high hurdle to meet.

Also, only those women who are “non-exempt” under the Fair Labor Standards Act (FLSA) are covered. The FLSA is a complicated law, but non-exempt employees are generally hourly workers who must be paid overtime. If you make more than $455 a week and have any supervisory responsibility, you may be exempt and therefore not covered by the breastfeeding law. This big loophole leaves out a lot of breastfeeding mothers.

 “In a perfect world, bosses would be understanding and accommodate nursing moms’ needs during those few months when they are pumping milk,” adds Spiggle. “After all, few people dispute the benefits of breastfeeding for babies. It’s healthier than formula, not to mention cheaper.”