The federal government is strongly urging employers to give transgender employees access to bathrooms that correspond to their gender identity, marking a new policy front in the fast-moving campaign for transgender equality.

"It is essential for employees to be able to work in a manner consistent with how they live the rest of their daily lives, based on their gender identity," the Occupational Safety and Health Administration wrote in its four-page Guide to Restroom Access for Transgender Workers posted last week on the agency's website.

The guide is explicit about saying that restroom access for transgender workers is a civil rights issue as well as a health and safety one.

"Restricting employees to using only restrooms that are not consistent with their gender identity, or segregating them from other workers by requiring them to use gender-neutral or other specific restrooms, singles those employees out and may make them fear for their physical safety," OSHA, an arm of the Labor Department, wrote, calling its guidance "best practices" for employers throughout the country.

In some workplaces, "questions can arise . . . about which facilities certain employees can use," OSHA said, explaining that someone's "internal gender identity" may be different from the sex they were assigned at birth.

"A person who identifies as a man should be permitted to use men's bathrooms, and a person who identifies as a woman should be permitted to use women's restrooms."

The US federal government has ensured such access for transgender workers since 2011. But advising businesses to do the same could generate tension with the business community, as a wave of legislation and litigation is making transgender workplace issues a hotly contested legal and cultural issue.

As the transgender movement has become more visible, controversies have roiled school systems and offices over privacy and the appropriate way to handle restroom preferences for those who are shifting genders. Many private-sector companies now have written policies, OSHA noted, the core belief of which is that "all employees should be permitted to use the facilities that correspond with their gender identify."

Among the many forms of discrimination that advocates for transgender men and women say they face on the job, bathroom restrictions have been among the most emotionally painful.

"Transgender people have experienced discrimination in restrooms," said Sarah Warbelow, legal director for the Human Rights Campaign, a gay and transgender rights group. "It certainly is the lived experience of trans people all over this country."

The June 1 OSHA recommendation, which does not carry the force of law, came out the same week that Caitlyn Jenner, the Olympic athlete formerly known as Bruce, appeared on the cover of Vanity Fair magazine. But OSHA spokeswoman Laura McGinnis said that the policy was developed over several months with the National Center for Transgender Equality.

"By issuing this guidance, OSHA hopes to assist employers in developing their own practices and procedures to ensure that none of their employees will suffer the adverse health effects that can result if toilets are not available when needed," McGinnis said. A regulation would have been stronger, but it can take seven to 10 years for the agency to set standards through regulation.

OSHA's stand is part of a broader push by the Obama administration to give protections to lesbian, gay, bisexual and transgender Americans. Obama signed an executive order last year that prohibits job discrimination against federal LGBT employees and companies that do business with the government. The Justice Department issued a memo late last year clarifying that bans on sex discrimination also prohibit employment discrimination based on gender identity or being transgender.