If they are fully informed, do employees with a certain medical condition have a right to work at jobs that can be hazardous to the health of people in their condition?

Or can company policy or OSHA regulations justifiably prevent them from doing so for their own good?

THE UNOBTRUSIVE FACTORY SITS BEHIND A hill-side shopping center in the small college town of Bennington, Vermont. Inside, the men and women make lead automobile batteries for Sears, Goodyear, and other companies. However, until the 1990s, none of the women employed there was able to have children. The reason was simple. The company, Johnson Controls, Inc., refused to hire any who could.122 Why? Because tiny toxic particles of lead and lead oxide fill the air inside the plant. According to the company, the levels of lead are low enough for adults but too high for children and fetuses. Numerous scientific studies have shown that lead can damage the brain and central nervous system of a fetus. Moreover, lead lingers in the bloodstream, which means that fetuses can be affected by it even if a woman limits her exposure to lead once she learns she is pregnant.
Because of this, Johnson Controls decided that it would exclude women at all fourteen of its factories from jobs that entail high exposure to lead—unless they could prove that they couldn’t become pregnant. The company made no exceptions for celibate women or women who used contraceptives.