Makers of unpasteurized fruit and vegetable juices must take strict new safety steps to ensure the products aren't contaminated with salmonella or other germs, under new government regulations announced yesterday.

These steps could prevent 6,000 Americans a year from being sickened, the Food and Drug Administration said.

"We believe this will provide a very high level of [safety] assurance to consumers," said FDA food chief Joseph Levitt.

Also yesterday, the FDA issued new consumer warnings about listeria, a common food-borne germ that can kill the elderly or people with weak immune systems and can cause miscarriages even if pregnant women experience no symptoms themselves.

Unlike many other germs, listeria can grow even in properly refrigerated foods. The FDA is researching how long perishable, ready-to-eat foods can last in the refrigerator, but it warned consumers yesterday to eat such foods fairly quickly instead of keeping them for weeks.

The FDA has long urged high-risk consumers not to eat hot dogs or luncheon meats unless they're reheated until steaming, and not to eat soft cheeses such as feta, brie or Camembert. (Hard or semisoft cheeses such as mozzarella, pasteurized cheese slices, and cream or cottage cheese are okay.)

But Thursday, the agency added new foods that high-risk people shouldn't eat: Refrigerated pa^te{acute}s or meat spreads and refrigeration-required smoked seafood -- the kind often labeled "lox," "jerky," or "nova-style." Canned, non-refrigerated versions are okay, however.

As for juice safety, the vast majority of U.S. juices already are pasteurized -- they say so on the label -- and thus pose little risk.

But a string of outbreaks prompted the FDA to warn that unpasteurized juices can be a serious risk: In 1996, unpasteurized apple juice tainted with E. coli bacteria sickened 70 people in the western United States and Canada, including a child who died. In 1999, salmonella-tainted unpasteurized orange juice sickened 423 people in 20 states. Last year, more salmonella-tainted orange juice sickened 88 people in six western states.

Under the new rules, if juice-makers don't pasteurize they must take other germ-killing steps -- ultraviolet light treatment or specially cleaning orange peel before squeezing the juice, for example. They must have a system in place to prove the juice is safe, and some companies would have to test juice before shipping it to prove there's no contamination. FDA inspectors will do spot-testing to make sure the system is working.

The U.S. Apple Association, which had worried about the impact of the rules on small juice- and cider-makers, declined to comment because officials had not read the new rules.