In an office bathroom, amid the sounds of toilets flushing, a new mother pumps milk from her breasts into bottles that will later be fed to her newborn child.

At another company across town, a mother hides in a supply closet filling plastic sandwich bags with her milk, and praying that none of her co-workers will need a pencil or pen.

Such unpleasant scenes, say women's advocates, are becoming more common with the growing presence of women in the workplace.

With more than 67% of all women of child-bearing age in the labor force--according to a 1989 medical study--some women's advocates predict that the issue may soon emerge from the shadows of bathroom stalls and supply closets, to become a part of the national discussion on the needs of working mothers and families in general.

The 1989 study, which appeared in the journal of the American Academy of Pediatrics, also noted that in the mid-1980s more than 40% of women with infants 1 year old or younger worked full or part time.

What the advocates want is for employers to give women the time and privacy to use breast pumps that allow them to store their milk for later.

Some experts and new mothers say the need for safe, clean places for women to pump milk is almost as important to some working women as more commonly discussed issues such as family leave and flex time.

"If you think about it, would you go and prepare your own lunch in a toilet stall?" asked Rona Cohen, an assistant clinical professor of maternal child health at UCLA's School of Nursing. "We wouldn't do that, but yet we're preparing our baby's food in toilet stalls.

"It's really been difficult for women. I know of women who have been threatened that if they do this activity on the work-site they will be fired . . . yet, breast-feeding makes good business sense."

Nell Merlino of the New York-based Ms. Foundation for Women agrees. "As industries start to reorganize one of the things they are examining is how to integrate work and family better," she said. "They have become places that are very separate from the rest of our lives and women are forced to try and change that because they have so much responsibility."

In some places, change has already started to occur. For the past five years the Los Angeles Department of Water and Power has offered employees a lactation program complete with classes, 24-hour counselors, a pump for each mother and a lactation room. This year, Burbank implemented the same program for its employees, including an officer from the Police Department.