WASHINGTON (AP) - Supermarkets and restaurants spooked by food poisonings linked to fruits and vegetables are making suppliers hire inspectors to check farms and packing operations.

Produce is responsible for an estimated 10 percent of all outbreaks of foodborne illnesses, yet the government has no mandatory rules for the safe growing and packing of fruits and vegetables - only voluntary guidelines.

An inspection in Washington state caused a farmer to move a lettuce field away from a septic system that sometimes overflowed. In other places, tests of irrigation water are turning up microbial contamination, a major cause of poisoned produce. In Mexico, packing sheds have been enclosed to protect produce from contamination.

Trade groups representing produce suppliers, supermarkets and restaurants have agreed on inspection guidelines that are to be released later this month.

Grocery giants Albertson's and Safeway were the first major supermarket chains to ask for the audits, and Publix, a large Southeast chain, recently followed. Wal-Mart, A&P and Kroger, the nation's largest grocer, are considering similar programs, industry officials say.

The inspectors serve as ``the police of our operations, which is good,'' said Francisco Obregon, a packer who sells Mexican-grown tomatoes, peppers and other produce to U.S. stores.

``The industry doesn't want the government to come in and lay out regulations,'' said Eric Engbeck, director of agricultural certification programs for Scientific Certification Systems, an Oakland, Calif., auditing firm. ``If they can voluntarily solve the problem and reduce the risk, they can possibly get rid of the reason for the government coming in.''

Consumer advocates say the inspections are no substitute for government regulation, and inspectors themselves say there is no guarantee that produce suppliers will fix the problems found in the audits.

Auditing is ``a good step, but it's voluntary, so it doesn't guarantee that a consumer knows the safety or quality of the produce,'' said Caroline Smith DeWaal, food-safety director for the Center for Science in the Public Interest, an advocacy group.

Over the past decade, 82 food-poisoning outbreaks have been linked to tainted sprouts, lettuce and other produce, almost as many as beef, according to data compiled by CSPI.

In late May, the Food and Drug Administration warned that salmonella-contaminated cantaloupes from Mexico had been linked to two deaths and numerous illnesses in 14 states from Massachusetts to California. Other scares have included hepatitis-contaminated strawberries and bacteria-poisoned sprouts and raspberries.

``What the audits are doing is increasing the awareness and basically providing a more systematic way of going through the farm and asking: Are you controlling your workers? Are you controlling your water? Are you controlling your applications of fertilizer, especially organic fertilizer?'' said Linda Harris, a food-safety expert at the University of California-Davis.

The new standards that produce suppliers have worked out with the supermarket and restaurant industries will follow the voluntary guidelines released by FDA in 1998.

Among the FDA recommendations: treat manure to kill bacteria before it's used as fertilizer; keep contaminated irrigation water away from produce; train workers to wash their hands properly and make sure they have access to toilets; keep packing facilities clean and free of pests.

Albertson's and Safeway notified their produce suppliers in 1999 that they wanted the inspections done.

Safeway, the nation's 3rd-largest grocer according to the trade magazine Supermarket Business, has been phasing in its auditing requirement on a commodity-by-commodity basis, starting with lettuce. Suppliers are allowed to pick from three auditing firms that Safeway has approved. ``Our ultimate goal is to assure the safest product available,'' said Safeway spokeswoman Debra Lambert.

Albertson's, ranked No. 2, initially gave its suppliers until April 2000 to comply, but many were unable to meet the deadline. The company said it is still working to bring those suppliers into compliance.

Copyright 2001 The Associated Press. All rights reserved.