A company finds birth-defect hazards at the site of one of its production lines. Solution: Take women off the production line. New company policy: Men can have the production jobs, and women -- unless they can prove they are infertile -- cannot.

Is this a laudable way to protect babies who might otherwise have been born deformed? Or is it sex discrimination that costs women their jobs and leaves men endangering their own reproductive systems?

Nearly buried in the arguments over crop economics and worker safety, the debate over "fetal protection policies" has resurfaced in the effort to ban the popular weedkiller dinoseb. When a federal judge in Oregon told some northwestern growers last April that they could use dinoseb despite the Environmental Protection Agency's order to suspend it, a coalition of environmental and labor attorneys asked to participate in the appeal -- arguing, in part, that the judge was forcing employers to discriminate against women.

"A judicial order that in effect orders employers not to employ women in jobs available to men is perhaps unique in modern jurisprudence," the attorneys wrote.

U.S. District Court Judge James A. Redden had ordered measures designed to protect workers from a chemical linked to health problems, including sterility and birth defects. Women "of child-bearing age, i.e., under the age of 45," Redden said, could not be involved in any aspect of dinoseb application.

The language was taken almost directly from an earlier EPA order allowing extremely limited use of dinoseb. But the concept of fetal-protection policies, which first aroused national attention when five women in the late 1970s underwent sterilization to keep their jobs at a West Virginia chemical plant, has disturbed labor and women's groups for some time.

"That's not health protection, that's exclusion," said Joan Bertin, an American Civil Liberties Union lawyer who has followed this issue closely and joined in the challenge to the Oregon court order. The EPA's initial dinoseb suspension order, Bertin and other attorneys have pointed out, says the chemical also may cause sterility and other health problems in men.

"You can't solve the problems that relate to toxic substances by just excluding women and pretending you've solved the problem," Bertin said. "It's deceptive with regard to the health status of other people who continue to be exposed to the chemicals, and it's discriminatory to the women."

Although no national survey has tallied the number of American companies that bar fertile women from some jobs, Bertin recently completed a book chapter in which she named 16 major companies as having publicly been found with in-house fetal-protection plans. Du Pont and a battery producer called Globe-Union are among the listed companies that independently confirmed that they maintain some separate and more rigorous safety standards for fertile women.

"I fear the list is the tip of the iceberg," Bertin said. "There's a lot of companies that do it, but don't have it written down . . . . It appears to be a very popular practice."

Globe-Union, now the battery division of a Milwaukee-based company, Johnson Controls, has been sued by the United Auto Workers because the company since 1982 has refused to allow fertile women to work in areas where they would be exposed to lead dust and fumes. Johnson Controls maintains that the dust and fumes are unavoidable byproducts of lead battery production and that developing fetuses have a much higher sensitivity to lead than adults do.

"We as a company just will not risk having a child exposed," said Jean Beaudoin, health and safety manager for Johnson Controls. "Our concern is, we don't want to feel the moral responsibility of having contributed to a problem with one child of one employe. It's not a numbers game."

But UAW officials say lead exposure leaves men with reproductive problems, too -- problems that can be passed on to their offspring. "Our view is that you can't find a difference," said Frank Mirer, a toxicologist who directs the UAW health and safety department. "We think the science proves you ought to have the same {safety} level for men."

Over the last five years, three appellate courts have examined challenges to fetal-protection policies, Bertin said, generally ruling that companies must meet a strict set of guidelines to defend the practice -- they must prove, for example, that male workers are not similarly susceptible to reproductive problems. No company has met those guidelines in court, Bertin said.

Some concerns about reproductive problems also have arisen recently in the semiconductor industry, which was shaken earlier this year by the results of a University of Massachusetts study conducted at the Digital Equipment Corp. in Hudson, Mass. The study, which has since been criticized for methodological problems that included a small sample size, found that women in one production area had miscarriages at twice the national average rate.

No rush to implement new fetal-protection policies has been reported within the semiconductor industry, in which women do much of the production work. AT&T instituted a policy transferring pregnant production-line workers to other jobs at comparable pay, and the Semiconductor Industry Association has created a "scientific advisory panel" to begin working toward its own study of reproductive problems in the plants.

"The study raised questions," said Shield Sandow, an association spokeswoman, "and we need to be the ones to address them."