National Residue Program

What is the U.S. National Residue Program?

The United States National Residue Program (NRP) for Meat*, Poultry, and Egg Products is an interagency program designed to identify, prioritize and analyze chemical residues and contaminants in meat, poultry, and egg products. The U.S. Department of Agriculture’s (USDA) Food Safety and Inspection Service (FSIS) administers this program. FSIS publishes the NRP Residue Sampling Plan (historically published as the “Blue Book”) each year to provide information on the process of sampling meat, poultry, and egg products and testing them for chemical compounds of public health concern.

The NRP is an important component of the FSIS mission to protect the health and welfare of the consumers by regulating domestic and imported meat, poultry, and egg products and to prevent the distribution into commerce of any such products that are adulterated or misbranded.

(*NOTE: The 2008 Farm Bill amended the Federal Meat Inspection Act (FMIA) to make all fish of the order Siluriformes amenable to the FMIA and, therefore, subject to FSIS inspection.)

How does the Program Work?

An essential aspect of food safety in meat, poultry, and egg products is the control of residues that may result from the use of animal drugs and pesticides, or from exposure to environmental contaminants.

The United States has a complex residue surveillance and control system, with rigorous processes for approval, sampling, testing, and enforcement. FSIS administers this regulatory program under the Federal Meat Inspection Act (FMIA) (21 U.S.C. 601 et seq.), the Poultry Products Inspection Act (PPIA) (21 U.S.C. 453 et seq.), and the Egg Products Inspection Act (EPIA) (21 U.S.C. 1031 et seq.). FSIS collects and tests samples of domestic and imported meat (including Siluriformes fish products), poultry, and egg products for residues. The NRP assists FSIS in meeting its mission to protect the public’s health by ensuring that meat, poultry, and egg products are safe, wholesome, and accurately labeled.

The NRP is designed to provide a structured process for:

1. Identifying and evaluating chemical compounds intentionally and unintentionally used in food animals;
2. Testing for chemical compounds of concern;
3. Reporting test results; and
4. determining the appropriate regulatory response to findings of chemical residues.

FSIS-Regulated Establishments

What Type of Sampling is Performed in FSIS-Regulated Establishments for the U.S. National Residue Program?

The NRP sampling plan guides the collection of domestic meat, poultry, and egg product samples and the import reinspection of meat, poultry, and egg products. The domestic sampling plan includes surveillance sampling, inspector-generated, and special project sampling in both federal and state-inspected slaughter facilities. The import reinspection sampling plan encompasses normal sampling, increased sampling, and intensified sampling. Details on FSIS residue sampling policy and procedures can be found in the following FSIS Directives:

• FSIS Directive 9900.6, for sampling imported meat, poultry, or egg product shipments presented for import reinspection at United States port-of-entry;
• FSIS Directive 10,800.1, for sampling in domestic slaughter establishments;
• FSIS Directive 14,010.1, for sampling fish of the Order Siluriformes from domestic establishments; and
• FSIS Directive 14,100.1, for sampling fish of the Order Siluriformes presented for import reinspection at United States port-of-entry.

Surveillance Sampling

Surveillance sampling is the scheduled sampling of specified slaughter subclasses [Animal Production Class Nomenclature (PDF Only)] at the time of slaughter, after a carcass has passed antemortem inspection. Carcasses are randomly selected within a given production class for sampling, with the goal of providing a nationally representative sample that can be used to determine baseline levels of chemical residues. The establishment must hold or control livestock carcasses selected for testing pending the test results. For poultry carcasses, FSIS recommends that the establishment holds the specific poultry carcasses selected for residue testing pending the test results.

The animal production classes that are included in the FY2020 surveillance sampling plan can be found in the Domestic and Import Reinspection Sampling Plans table.

Inspector-Generated Sampling

FSIS inspectors conduct inspector-generated sampling when they suspect that animals may have violative levels of chemical residues. Currently, inspector-generated sampling targets individual suspect animals, suspect animal populations, and animals retained or condemned for specific pathologies.

The Public Health Veterinarian (PHV) selects a carcass for sampling based on the criteria outlined in FSIS Directive 10,800.1 (i.e., animal with disease signs and symptoms, producer history of violative levels of residues, or as a follow-up to results from random scheduled sampling). The PHV is to perform a KIS™ test on any carcass suspected of containing violative levels of chemical residues and on any carcass exhibiting signs of systemic conditions (e.g., septicemia, peritonitis, pyemia). When a PHV detects evidence of a disease that might have been treated with certain veterinary drugs or an injection site, the carcass is retained by FSIS. Tissue samples are collected from the carcass and tested for the presence of antibiotic drug residues using the Kidney Inhibition Swab test (KIS™ test), an in-plant screening test. If the KIS™ test is negative for antibiotic drug residues included in the screen, the carcass may continue to be retained for additional testing if other drug or chemical residues are suspected; otherwise, the carcass is released to the establishment. If the KIS™ test result is positive, the carcass is retained by FSIS pending the confirmation results of FSIS laboratory testing. The PHV condemns carcasses and parts from animals found to contain violative levels of residues.

The state inspectors from state-inspected establishments that are “at least equal to” the federal requirements collect and submit samples of kidney, liver, and muscle directly to the FSIS laboratory from animals suspected of having violative residues.

Special Project (Exploratory) Sampling

When a necessary analytical project cannot be performed on samples that are already being collected as part of the surveillance or inspector-generated sampling, FSIS may collect special project samples. The duration of these sampling plans varies based on the situation.

Special project sampling may be specific to individual animals within a production class or may be conducted at a herd or flock level. An exploratory sampling program designed for livestock or flocks originating from the same farm or geographic region may be necessary to determine the level of exposure to one or more chemicals.

Whether an establishment must hold or control livestock carcasses subject to special project sampling depends on which chemical compounds are included in the testing and the regulatory decisions FSIS may take based on the test results.

In FY2020, special project sampling includes the production classes described in the Animal Production Class Nomenclature document.

Imported Products

What Type of Sampling and Testing is Performed on Imported Products for the U.S. National Residue Program?

Imported meat, poultry, and egg products are sampled through the point-of-entry Import Reinspection Sampling Plan, a chemical residue monitoring program conducted to verify the equivalence of inspection systems in exporting countries to U.S. standards. All imported products are subject to reinspection, and one or more Types of Inspection (TOI) are conducted on every lot of product before it enters the United States. The reinspection of imported products includes chemical residue testing. There are three levels of chemical residue reinspection:

• Normal sampling: random sampling from a lot;
• Increased sampling: above-normal sampling resulting from an Agency management decision; and
• Intensified sampling: additional samples taken when a previous sample for a TOI failed to meet U.S. requirements.

The structure of the import reinspection sampling program is based on criteria used to develop the domestic plan. The estimated annual amount of product imported into the United States is used to assign the number of samples. The importer of record must maintain control of the imported product that is subject to normal and increased import reinspection sampling pending the test results. For intensified import sampling, FSIS retains the product lot pending test results.

The testing of samples collected from imported product is similar to the domestic plan, with two important exceptions. Raw product testing from samples collected at the U.S. point-of-entry is rare, because many countries ship only processed products due to restrictions based on the presence of foreign animal diseases. When the importation of raw products is allowed, the raw product typically consists of muscle tissue only. FSIS requires exporting countries to identify the animal species in each product but does not require them to identify the production class. Imported meat and poultry testing is categorized by species (e.g., poultry or porcine); egg products are distinguished as a separate category. For these reasons, the compounds selected for analysis in the import plan may not necessarily be the same as those in the U.S. domestic plan.

Chemicals Tested

Which Chemical Compounds are the Samples Tested for Under the U.S. National Residue Program?

The range of chemical compounds evaluated for inclusion in the NRP is comprehensive in scope. Testing includes approved and unapproved veterinary drugs, pesticides, and environmental contaminants known or suspected to be present in food animals in the United States or in countries exporting products to the United States. These three broad categories of chemical residues and contaminants are described below. FSIS partners with the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) to decide which specific chemical compounds to test for within each category.

Veterinary Drugs

This category includes veterinary drugs that are regulated by the FDA under the Federal Food, Drug, and Cosmetic Act (FFDCA). FDA has established tolerance levels in meat, poultry, and egg products for many veterinary drugs, which can be found in Title 21 of the Code of Federal Regulations (CFR). The current list of veterinary drugs included in the NRP, as well as the numbers and types of meat, poultry, and egg product samples tested for veterinary drugs, can be found in the List of Chemical Residues by Category / Class document.

Pesticides

This category includes pesticide chemicals regulated by EPA, under the FFDCA and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). EPA has established tolerance levels for many registered pesticides, which can be found in Title 40 of the CFR. The current list of pesticides included in the NRP, as well as the numbers and types of meat, poultry, and egg product samples tested for pesticides, can be found in the Pesticide Prioritization Framework for the U.S. National Residue Program document.

Contaminants

This category includes any chemical compound included in the NRP that is not a veterinary drug or a pesticide chemical. The current list of contaminants included in the NRP, as well as the numbers and types of meat, poultry, and egg product samples tested for contaminants, can be found in the List of Chemical Residues by Category / Class document.

Annual Plan Creation

How does FSIS Develop the U.S. National Residue Program Sampling Plan Each Year?

FSIS partners with the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) as the primary Federal agencies that manage the NRP. This program requires the cooperation and collaboration of these and other agencies for its successful design and implementation.

Each year, representatives from FSIS, FDA, EPA, USDA’s Agricultural Research Service (ARS), and the USDA’s Agricultural Marketing Service (AMS), as well as the Department of Health and Human Services’ (DHHS’) Centers for Disease Control and Prevention (CDC), convene a meeting of the Surveillance Advisory Team (SAT) to evaluate chemical compounds for inclusion in the NRP for the following fiscal year. The SAT consists of experts in veterinary medicine, toxicology, chemistry, and public health who provide professional advice, as well as information on veterinary drug and pesticide use in animal husbandry. The SAT meeting is used to determine which chemical compounds represent a public health concern and warrant inclusion in the NRP, either on a permanent or exploratory basis.

The sampling plan design begins with a list of residues that may occur in meat, poultry, and egg products and are of concern to human health. FSIS coordinates an annual meeting of the SAT members to identify and prioritize chemical compounds of public health concern. FSIS combines this information with historical data on violation rates for each chemical compound to develop the domestic sampling and import reinspection plans. These sampling plans guide the allocation of FSIS laboratory, supply, and inspection resources.

The SAT has provided a risk-based prioritization of pesticides, as described in the Pesticide Prioritization Framework for the U.S. National Residue Program document, which informs future decisions to add additional pesticides to its analytical method. FSIS is currently evaluating an approach to identify and prioritize veterinary drugs associated with FSIS-regulated products.

Additional factors considered when developing the domestic and import scheduled sampling plans include:

• The food animals likely to be affected by each chemical compound or compound class;
• The availability of analytical methods to identify the chemical compound or compound class and the FSIS laboratory capacity to conduct the analyses; and
• The existence of a regulatory tolerance.

Test Results

How are the Residue Test Results Used?

FSIS and its partners use the testing data collected through the NRP in a variety of ways.

Monitoring

For example, NRP results inform the agencies about veterinary drug and pesticide use in the food animal industry, compliance with regulations governing veterinary drug and pesticide use, and information on the presence of environmental contaminants that may affect the food supply. Residue testing data are used by the regulated establishment to make decisions about its food safety program, including its suppliers of live animals. In many cases, particularly for veterinary drugs and pesticides, the test results reported by FSIS laboratories are compared to a quantitative acceptable level (i.e., tolerance or action level) to verify that meat, poultry, and egg products tested are safe and wholesome and do not contain levels of a chemical compound that would render the product in question adulterated under the FMIA, PPIA, or EPIA.

Actions Taken on Violations

A violation occurs when an FSIS laboratory detects a chemical compound at a level that exceeds an established tolerance or action level for that compound, or if the specific type of chemical compound detected renders the product adulterated in the absence of an established tolerance. FSIS enters information about residue violations into the Residue Violator Tracking (RVT) system, an FSIS-FDA interagency database. FSIS provides establishment and the designated FSIS inspection program personnel (IPP) with the analysis results and notifies the producer via certified letter. Under best practices, the establishment also notifies the producer that an animal from that business has been identified as having a residue violation.

In addition, FSIS shares the violation data with EPA and FDA, where the latter agency has on-farm jurisdiction. FDA and cooperating State agencies investigate producers linked to residue violations and, if conditions leading to residue violations are not corrected, can enforce legal action.

To notify the public and the industry of repeated residue violations by the same producer, FSIS posts a weekly Residue Repeat Violators List on its website that identifies producers with more than one violation on a rolling 12-month period. The list provides helpful information to the USDA AMS School Lunch Program processors and producers who are working to avoid illegal levels of residues, serves as a deterrent for violators, and enables FSIS and FDA to make better use of resources (list for processors and producers). Because FSIS updates are posted weekly, FDA may not have investigated each violation at the time of publication.

Strategic Planning

FSIS further uses data collected under the NRP to continuously reassess policies and programs to assure they are effective and protect public health. Even in the absence of a violation, testing data are routinely reviewed and analyzed for trends and individual results may trigger specific agency responses, including consultation between FSIS, FDA, and EPA, as well as follow-up actions if appropriate. For example, FSIS has conducted exploratory analyses in some production classes for chemicals like metals, dioxin, and, beginning in fiscal year 2020, per- and polyfluoroalkyl substances (PFAS).

Analytical Methods

What Analytical Methods are used for Testing under the U.S. National Residue Program?

FSIS uses a variety of analytical methods to detect, identify, and quantify chemical residues that may be present in meat, poultry, and egg products. When possible, FSIS uses multi-residue methods for the detection and confirmation of many chemical compounds in a single method. The veterinary drug method screens and confirms for over 100 analytes while the pesticide method screens and confirms over 100 pesticides.

The FSIS Chemistry Laboratory Guidebook (CLG) lists the analytical methods currently available to the agency and describes the analytical process and performance characteristics of each method. One such performance element is the Minimum Level of Applicability (MLA). FSIS defines an MLA as the lowest level at which a method has been successfully validated for a residue in each matrix (meat or poultry). It also refers to the lowest level at which a laboratory analyst is expected to maintain ongoing proficiency in the method. FSIS will generally not report or act on any analytical results below the applicable MLA.

Changes for FY2020

Summary of Changes to the NRP For FY2020

FSIS uses a variety of analytical methods to detect, identify, and quantify chemical residues that may be present in meat, poultry, and egg products. When possible, FSIS uses multi-residue methods for the detection and confirmation of many chemical compounds in a single method. The veterinary drug method screens and confirms for over 100 analytes while the pesticide method screens and confirms over 100 pesticides.

1. Since FY 2016, FSIS has reported multiple avermectin violations in goats analyzed under the NRP. Therefore, in the FY 2020 NRP, all goats sampled will receive avermectin analysis.
2. In FY 2018, FSIS conducted an exploratory study to evaluate whether semicarbazide (SEM), the primary metabolite of nitrofurazone, could be detected in chicken samples before and after processing. In response to the results of this exploratory study, in FY 2020, FSIS will begin collecting young chicken carcasses at a point prior to chilling for nitrofuran analysis at establishments that slaughter greater than 4,000,000 heads per month.
3. In FY 2017, heavy calf and bull/stags were added to the NRP to increase surveillance. Since then no residues have been reported in these product classes; therefore, in FY 2020, FSIS will discontinue exploratory sampling of heavy calf and bull/stags.
4. To enhance surveillance of both lamb and mature sheep, in FY 2020, FSIS will redefine the sampling of this slaughter class, by creating a specific project code for lamb, and increase the total number of samples from 150 to 200, split equally between both lamb (100 samples) and mature sheep (100 samples).
5. With the support of FDA and EPA, FSIS will be taking a proactive approach to address the presence of PFAS (per- and polyfluoroalkyl substances) in FSIS-regulated products. In the FY 2020 NRP, condemned bovine samples collected under inspector-generated sampling will be analyzed for the presence of PFAS.
6. In FY 2020, the Agency will start using a next generation multi-residue screening method to strengthen its ability to detect animal drug residues. “Screening and Confirmation of Animal Drug Residues by UHPLC-MS-MS” (CLG-MRM3.00) will be an improvement over the current CLG-MRM1.08 method due to the use of more sensitive instrumentation. As a result, the number of animal drug residues analyzed in a sample will increase from 92 to 107 unique compounds. The method is applicable for the analysis of kidney and muscle samples in several slaughter classes (beef, pork, poultry, goat, and sheep), as well as Siluriformes (catfish) muscle and liquid egg products.