USDA’s Food Safety and Inspection Service (FSIS), the government agency responsible for inspecting meat and poultry, has established acceptable levels of Salmonella contamination for different types of meat and poultry.

In 1998, FSIS began enforcing a new Salmonella standard by testing raw and ground products for the presence of the pathogen. The purpose of the program was to use microbial sampling to determine when plants were not controlling food safety hazards in their production processes. Testing also was supposed to objectively indicate when industry and government were not fulfilling their food safety responsibilities.

The acceptable level of contamination established for each product was based on the average level of Salmonella present for each class of product during initial baseline tests. Consequently, FSIS acceptable percentage of Salmonella contamination varies greatly by product.

To determine the contamination level for a particular plant, FSIS tests a sample of the finished product each day the plant is operating until the requisite number of samples is taken. The number of required daily samples differs by species. So, for example, the testing period for a plant that slaughters steers and heifers would be as long as is necessary to collect 82 daily samples, whereas the testing period for a broiler chicken plant would be long enough to collect 51 daily samples. The length of the testing period is also affected by the frequency with which a plant produces the product.  Some small plants do not produce every day, and therefore the testing period is longer at these plants to collect the same number of samples. The contamination rate of a plant is the percentage of the daily samples that are contaminated with Salmonella >during the testing period. 

As a matter of practice, if the plant’s contamination rate does not exceed the regulatory standard, it will not typically undergo another testing period for approximately one year.  However, on January 28, 2008, FSIS announced that plants with half or fewer of the allowable number of positive samples in their last two testing periods would not be scheduled for more tests for 12 to 24 months.⁶ We believe this reliance on previous performance is misguided because circumstances in a plant can change very quickly. If the agency implements this proposal, consumers could be at greater risk because past data indicates that a plant with fewer than the allowable number of positive Salmonella test results in one period can fail to meet the performance standard in a subsequent testing period.  In other words, the data shows that good performance does not always last for the length of time that this new policy would allow between testing periods.  See plants marked with an asterisk in Chart 2 for examples of when this new policy could have delayed testing during periods of poor performance.    

Initially, FSIS established an enforcement program for its Salmonella program with actions getting progressively more serious with each additional failed testing period and culminating in withdrawal of inspection if the plant failed to comply with the Salmonella regulation for three consecutive testing periods. In 2001, however, a federal District Court ruled that the agency could not withdraw inspection solely based on a plant’s failure to meet the requirements of the Salmonella regulation. Since then, the agency reportedly increases the level of scrutiny at a plant with each successive Salmonella failure and may take enforcement action after considering the results of those investigations.

Overall, the results of the FSIS program have been disappointing. While the agency claims that the 1998 implementation of new “[inspection] and pathogen reduction programs represents one of the most significant changes in the regulation of the meat and poultry industry since the inspection program began in the early 1900’s,” ⁷ the percentage of broiler chickens found by the agency’s testing program to be contaminated with Salmonella actually increased from 10.83 percent in 1998 to 11.41 percent in 2006.⁸

Salmonella Testing in Broiler Chickens

To determine the contamination level for a particular broiler chicken plant, the agency collects daily samples until it has 51. For high volume plants that are producing five to seven days each week, this testing period usually takes between two and three months.

To collect a single sample, an FSIS inspector takes a carcass from the end of the plant’s production line, puts it in a sterile plastic bag with a chemical solution and agitates it for one minute. This solution is then sent to an FSIS lab to determine if the carcass was contaminated with Salmonella.

Since 1998, the agency has published only generalized data from the program, usually on an annual basis. In 2006, the agency announced it would begin publishing quarterly data and it issued the first quarterly report on June 23, 2006.   The agency also announced that, to increase incentives for plants to produce safe food, it would begin categorizing plants based on their success in meeting the regulatory standard and would begin publishing the status of individual plants on its web site. While FSIS repeated the same intention in a January 2008 Federal Register notice,  it has thus far failed to report individual plant status. 

Under the agency’s categorization scheme, Category 3 plants are those that fail, meaning that for broilers more than 12 of the 51 samples (24 percent) test positive; Category 2 plants pass with seven to 12 of the 51 samples (13 to 24 percent) registering a positive result; and Category 1 plants are those that pass, with zero to six of the samples testing positive for Salmonella (a zero to 12 percent contamination rate) in both the current and the previous testing set.

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