U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
Pesticide Residue Monitoring Database Users' Manual
April, 2000

U.S. FOOD AND DRUG ADMINISTRATION
PESTICIDE MONITORING DATABASE

USER'S MANUAL

LIST OF CONTENTS

Introduction

Background: FDA's Pesticide Programs

Data Files Structure and Content

Use of Files

INTRODUCTION

The U.S. Food and Drug Administration (FDA) operates an ongoing program of monitoring for pesticide residues in foods. The results of the program are published annually. Tables, figures, and appendices in each report are based upon summarizations of analytical data resulting from collection and analysis of food samples in field laboratories. Data files are made available here for the user who wishes to scrutinize further any aspect of analytical data and results.

Unlike the dBase III+ databases that were made public in 1992-1997, the 1998 and 1999 information is presented as a series of tab-delimited text files. This change in approach requires the user to create databases from the files, rather than merely using a pre-established database. The advantage of offering files in this format is that the user may create databases in any software available; most database or spreadsheet software should work with these files if adequate disk space and RAM are available.

Data in these files are the same as those provided in previous years, i.e., six files of summary data, in varying levels of summarization, as well as one file of analytical data related to each sample, and another file that describes the capabilities of the analytical methods in terms of the residues detectable. An additional file decompresses to four lookup tables, each of which provides further information about particular data entries.

Directions for downloading and executing (decompressing) the individual files follows the background information about the pesticide program and the details of file structure and content.

BACKGROUND: FDA'S PESTICIDE PROGRAMS

Regulatory Responsibility for Pesticides

The FDA shares responsibility with two other federal agencies for the regulation of pesticides. The Environmental Protection Agency (EPA) registers (i.e., approves) the use of pesticides based on evidence that their use will not cause an unreasonable risk to health or the environment. EPA is also responsible for establishing tolerances if use of a pesticide may lead to residues in food. (A tolerance is the maximum amount of a residue that is permitted in or on a food.) With the exception of meat, poultry, and certain egg products, for which the Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture (USDA) is responsible, FDA is charged with enforcing tolerances in imported foods and in domestically produced foods shipped in interstate commerce. FDA also acquires incidence/level data on particular commodity/pesticide combinations and carries out its market basket survey, the Total Diet Study. USDA's Agricultural Marketing Service (AMS), through contracts with participating states, conducts a residue testing program directed primarily at raw agricultural products. FSIS and AMS pesticide residue data are reported independently by those agencies.

FDA Pesticide Monitoring Program

The FDA pesticide monitoring program is comprised of three components: 1) regulatory monitoring; 2) incidence/level monitoring; and 3) the Total Diet Study. THE DATABASE PRESENTED HERE COVERS ONLY THE REGULATORY MONITORING COMPONENT. However, a brief description of the other two components is provided, and further information on them is available in the FDA annual reports, available from FDA's website.

Regulatory Monitoring

The regulatory monitoring component is directed toward enforcing tolerances in imported foods and in domestically produced foods shipped in interstate commerce. Under regulatory monitoring, FDA samples individual lots of domestically produced and imported foods and analyzes them for pesticide residues. Domestic shipments are collected as close as possible to the point of production in the distribution system; import samples are collected at the point of entry into U.S. commerce. Emphasis is on the raw agricultural product, which is analyzed as the unwashed, whole (unpeeled), raw commodity. Processed foods also are included.

Domestic and import food samples collected for analysis are classified as either "surveillance" or "compliance", this classification was dropped in 1999. Most samples collected by FDA are the surveillance type; that is, there is no prior knowledge or evidence that a specific food shipment contains illegal pesticide residues. Compliance samples are collected as follow-up to the finding of an illegal residue or when there is other evidence of a pesticide problem. Compliance samples include follow-up samples from the same shipment as a violative surveillance sample, follow-up samples from additional product from the same grower or shipper, and audit samples from shipments presented for entry into the United States with a certificate of analysis (i.e., shipments subject to detention without physical examination).

To analyze the large numbers of samples whose pesticide treatment history is usually unknown, analytical methods capable of simultaneously determining a number of pesticides are used. These multiresidue methods (MRMs) can determine about half of the approximately 400 pesticides with EPA tolerances, as well as many others that have no tolerances. The most commonly used MRMs can also detect many metabolites, impurities, and alteration products of pesticides with and without tolerances.

Single residue methods (SRMs) or selective MRMs may be used to determine pesticides not covered by an MRM. An SRM usually determines one pesticide; a selective MRM measures a relatively small number of chemically related pesticides. These types of methods are usually more resource-intensive per residue, and they may require at least as much time to perform as an MRM. They are much less cost efficient than MRMs.

The lower limit of residue measurement in FDA's determination of a specific pesticide is usually well below tolerance levels, which generally range from 0.1 to 50 parts per million (ppm). Residues present at 0.01 ppm and above are usually measurable; however, for individual pesticides, this limit may range from 0.005 to 1 ppm. In this database, the term "trace" is used to indicate residues detected, but at levels below the limit of quantitation.

Incidence/Level Monitoring

A complementary approach to regulatory monitoring, incidence/level monitoring has been used to increase FDA's knowledge about particular pesticide/commodity combinations by analyzing certain foods to determine the presence and levels of selected pesticides. In 1995, a survey of triazines was started and in 1997 the survey was completed.

Statistically based monitoring surveys, focusing on domestic and imported foods were initiated in 1992 and the results have been published. These statistically based surveys were initiated to determine whether FDA data acquired under regulatory monitoring are statistically representative of the overall residue situation for a particular pesticide, commodity, or place of origin. In FDA's surveillance sampling for pesticide residues, sampling bias may be incurred by weighting sampling toward such factors as commodity or place of origin with a past history of violations or large volume of production or import shipments. In addition, the total number of samples of a given commodity analyzed for a particular pesticide each year may not be sufficient to draw specific conclusions about the residue situation for the whole volume of that commodity in commerce. Therefore, the objective of these statistically based surveys is to determine whether violation rates, frequency of occurrence of residues, and residue levels obtained from such a sampling regimen differ from those obtained through FDA's traditional surveillance approach.

Total Diet Study

The Total Diet Study is designed to estimate dietary intakes of pesticide residues by various age/sex groups from infants to senior citizens. FDA personnel purchase foods from supermarkets or grocery stores four times per year, once from each of four geographical regions of the country. Each collection contains 261 food items (234 items prior to 1992) that have been selected on the basis of information obtained through nationwide dietary surveys. The 261 foods are representative of over 3500 different foods in the national surveys; for example, apple pie represents all fruit pies and fruit pastries. Each of the four collections is a composite of like foods purchased in three cities in that region. The foods are prepared table-ready and then analyzed for pesticide residues (as well as radionuclides, industrial chemicals, toxic elements, trace and macro elements, vitamin B₆, and folic acid). The levels of pesticides found are used in conjunction with food consumption data to estimate the dietary intakes of the pesticide residues.

DATA FILES STRUCTURE AND CONTENT

The following notes apply to all Summary Files.

1. The data files are in tab-delimited text format.

2. Throughout the data, surveillance samples and compliance samples are addressed separately because of the significant fundamental difference in the nature of the samples. The user is advised to be cognizant of this issue in using the data, particularly the data for compliance samples. Please review the definitions of surveillance and compliance that are given in the Introduction.

3. Because of the broad analytical coverage afforded by the multiresidue methods commonly used in FDA monitoring, a large number of pesticides typically are covered in analysis of a given country/food product combination. The listing in the data of coverage of a particular pesticide for a given country/food product combination should not be considered as indicating the existence of an EPA tolerance or known or anticipated usage of that pesticide on that product but rather as an indication of the capability of the analytical methods used.

4. Wherever possible, pesticide information in the data is expressed as a total of related residues (parent, metabolites, etc.). Examples are "DDT (TOTAL)" and "CHLORDANE (TOTAL)." However, in cases where the analytical behavior of related residue components differs significantly and therefore the analytical coverage of them would differ, the residue components are expressed separately.

5. The term "adverse" denotes a residue that: 1) exceeded a tolerance; or 2) had no tolerance for the food product involved and the residue level appeared to be of regulatory significance.

6. Data elements that provide "percent" information express the percent values in the form in which they best fit in a three-position field; examples of percent values are "3.7" and "26".

Structure of each Summary File follows:

PRODYYYY.TXT:  Summary File by Country/Sample Flag/Food Product Combination (where YYYY is the year)
Summary file by country/sample flag/food product combination (without regard to pesticide).

CHEMYYYY.TXT:  Summary File by Country/Sample Flag/Pesticide Combination (where YYYY is the year)
Summary file by country/sample flag/pesticide combination (without regard to product).

USYYYY.TXT, IMFRYYYY.TXT,  IMVEYYYY.TXT, IMOTYYYY.TXT:
Summary Files by Country/Sample Flag/Food Product/Pesticide Combination (where YYYY is the year)
Detailed data by country/sample flag/food product/pesticide combination.

*  The data elements pertaining to residue concentration (MEAN, MINIMUM, MEDIAN, NINETITH, and MAXIMUM) are based on the number of samples covered and are expressed in parts per million. Trace findings and samples in which no residue was detected were treated as zero in calculation of the MEAN. In the MINIMUM, MEDIAN, NINETITH, and MAXIMUM data elements, "T" represents a trace finding and "0" represents "none detected." The vast majority of these records indicate that no residues were found (i.e., RESFND=0) for that country/sample flag/food product/pesticide combination.

The following notes apply to the Analytical Data File.

1. The data file is in tab-delimited text format.

2. The structure of SMPLYYYY.TXT (where YYYY is the year), the file of individual analytical records, is considerably more complex than that of the other files and requires greater familiarization and caution by the user to use the file properly. The data reflect FDA monitoring results as entered into a computerized reporting system by FDA's field offices and are unedited.

3. For each analysis performed on a given sample, the following is entered: 1) one record for each residue that was found in the analysis; or 2) one record which states that no residues were found. The data file does not contain a "none detected" record for each chemical that was covered in a given analysis but was not found. Therefore, to determine which pesticides were covered in a given analysis or in FDA pesticide monitoring as a whole, or to determine the extent of coverage of a given pesticide, the user must also make use of the METHYYYY.TXT (where YYYY is the year) file that lists the pesticides known to be covered for the analytical method codes reported in the individual analytical records. ANALYTICAL COVERAGE CANNOT BE INTERPRETED SIMPLY BY EXAMINING THE RESIDUE CODES/NAMES REPORTED IN THE RAW DATA!

4. For most samples, more than one analysis is performed. Therefore, the file contains multiple records for most of the samples, even if no residues were found. The user must adjust for the multiple records per sample when processing the data to determine sample counts such as the number of samples analyzed, etc.

5. The analytical methods used for a given sample may overlap in coverage, i.e., a given pesticide may be covered by more than one of the methods used. The user must adjust for overlapping coverage when processing the data to determine the number of samples covered for a given pesticide.

6. More than one record may be entered for a given pesticide in a given sample. For example, there can be both an original analysis record and a check analysis record for a given pesticide in a given sample, and there can be records for a given pesticide for each subsample analyzed. The user must adjust for the multiple records per pesticide per sample when processing the data to determine the number of residues found and distribution of residue levels for a given pesticide. [In compilation of the summary data files in this package, FDA used the following criteria to select one record per pesticide per sample from the raw data: sort by analysis type field using sequence of check, additional, original, identification; within analysis type, sort by descending adverse flag (adverse results would then precede non-adverse results); within adverse flag, sort by subsample field after converting all non-blank subsample codes to a "dummy" code of "SS" (records for sample composite, which has blank subsample code, would then precede records for individual subsamples, and conversion of all non-blank subsample codes to a common "dummy" code will allow subsample with highest residue amount to be selected preferentially over other subsample results); within subsample field, sort by descending residue amount (after conversion to parts per million); within residue amount field, sort by descending trace field; then select the first record in the sort sequence to use in tabulating monitoring coverage and findings.]

7. In most cases, the individual sample data are reported by individual residue component (e.g., endosulfan I, endosulfan II, endosulfan sulfate) rather than as a total of components related to a given parent pesticide. (The list of pesticide names indicates which names found in the analytical data file are contained within a "total" entry in the summary files.) There are some samples for which results were reported both by individual component and as a total. For example, some samples have results reported for one analysis as "permethrin, cis" and "permethrin, trans" as well as a result from another analysis reported as "permethrin." The user must adjust for such situations when processing the data to determine the number of residues found and distribution of residue levels for a given pesticide.

8. The analytical methods routinely used in FDA pesticide monitoring also cover some industrial chemicals (e.g., polychlorinated biphenyls). Findings of the industrial chemicals are reported in the analytical data file but are usually excluded from summary data files.

9. As stated in item 2, the data file does not usually contain a "none detected" record for each pesticide that was covered in a given analysis but was not found. However, there is an exception in the case of analyses reported with extraction code 998 ("other methods used for determination of single components"), for which the analyzing laboratory reports the code of the pesticide that was covered in the analysis, even if it was not found. For analyses by methods other than "998", the analyzing laboratory may choose to enter the code for a given chemical that was covered but not found if they wish to highlight the result for some reason.

Structure of the Analytical Data File follows:

SMPLYYYY.TXT:  Analytical Data File (where YYYY is the year)
Analytical data for each individual sample, as entered by FDA field chemists.

Note that each record is uniquely identified by its combination of year/analyzing district/sample number/PAC/LID/entry number, and the file is provided in sequence by this record key.

The following notes apply to the File of Pesticides Covered by the Analytical Methods.

1. The data file is in tab-delimited text format.

2. This file contains a record for each individual residue (including individual components) covered by each analytical method used in FDA.

3. An analytical "method" is a given combination of extraction code and determination code.

4. Appearance of a record in this file reflects documented coverage based on recovery/response data received by FDA headquarters in Washington, D.C.

5. In some cases, residue findings may have been reported in the analytical sample data for pesticide/method combinations for which recovery and/or response data have not been documented.

6. The file does not list the industrial chemicals covered by the methods.

7. Some records in this file represent methods that have not been used in the current fiscal year.

Structure of the File of Pesticides Covered by the Analytical Methods follows:

METHYYYY.TXT:  File of Pesticides Covered by the Analytical Methods (where YYYY is the year)
List of pesticides covered by analytical methods used by FDA.

The following notes apply to the Other Lookup Tables.

1. No details are provided here for the structure of the individual files that result from decompression of ALLCODES.EXE. The ReadMe.txt file explains the other files.

2. The file called Prodcode.txt that results from decompression of ALLCODES.EXE is not available elsewhere on this web site because of its size (over 9000 records). All other files are also available from the links within this User Guide, but the version produced by ALLCODES.EXE is more suitable for importing into database software.

USE OF FILES

All data files for 1998 and 1999 are compressed (zipped) into self-extracting executable files. Execution of each downloaded file produces a tab-delimited text (.txt) data file. Structures and contents of each data file are described above. Each data file can be imported by most database or spreadsheet software. At least 50 MB of free disk storage space is needed to hold the decompressed 1998 data.

1. To install the complete set of data files, download each and save to your hard drive. The following files are necessary for complete installation of the data: PRODYYYY.EXE, CHEMYYYY.EXE, USYYYY.EXE, IMVEYYYY.EXE, IMOTYYYY.EXE, IMFRYYYY.EXE, SMPLYYYY.EXE, and METHYYYY.EXE

2. To execute data files in Windows, RUN each of the executable (*.exe) files to extract the tab-delimited text (*.txt) data file.

3. To execute data files in DOS, at the DOS prompt (in the Directory where the files are located), type the filename (without .exe) and press the <Enter> key. Repeat this operation for each file.

4. After decompression occurs, *.exe files can be deleted.

The following tables describe codes found in the records of the analytical data file:

District Code Definitions

Program/Assignment Code (PAC) Definitions

The following are code definitions for the general monitoring programs and special field assignments.

Sample Type Code Definitions

Laboratory Classification Definitions

To comment or request further information, contact Mark Wirtz, mwirtz@cfsan.fda.gov