United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 1 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

1. Purpose:

To ensure correct and consistent usage of the specific sampling terms associated with the

USDA/AMS-Microbiological Data Program (MDP) and Pesticide Data Program (PDP).

2. Scope:

This Standard Operating Procedure (SOP) shall be followed by all State personnel involved in

the management of sample collection for MDP and PDP.

3. Outline of Procedure:

 5.1 Glossary of Sampling Terms

4. References:

 Sample Advisory Committee Meeting, December 2-4, 2008

5. Specific Procedure:

5.1 Glossary of Sampling Terms

Alternate Site—the back-up site from the State's list of active sites where the sample should be

collected if it is not available at the Primary Site.

Aseptic—free of pathogenic microorganisms. (A pathogen is a microbe that is capable of

causing disease.) If something is aseptic it does not imply that it is sterile.

Chain of Custody—documentation (e.g., worksheets or logbooks) that records sample

movement from selection of the sample, to receipt at the laboratory, to final disposal of the

extract(s). This documentation allows for traceability of movement of each sample.

Cold-to-the-Touch—the temperature of the surface of an object that "feels" colder than one’s

own body temperature
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 2 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Cross-Contamination—the physical movement and transfer of chemical or illness-causing

agents from one person, object, or place to another

Delicate Commodity—a commodity that may easily be damaged or spoiled if not properly

packaged (to prevent movement) and kept cool (at a refrigerated temperature) during transport to

its respective laboratory. Strawberries are an example of a delicate commodity.

Distribution Center—a warehouse facility that purchases and receives food products from

multiple vendors, storesthe food products on its premises, then distributes the products to

multiple stores within its specific chain, e.g., a Safeway distribution center will receive, store,

and distribute food for all the individual Safeway retail stores within its geographic proximity.

Double/Triple Sampling—extra sampling during a specified period of time to make up for

times (most likely, seasons) when certain commodities are unavailable and therefore are unable

to be collected. Double or Triple Sampling must be approved by MPO and the laboratory

receiving the samples before it is initiated.

Electronic Sample Information Form (e-SIF)—digital version of the Sample Information

Form that is entered and submitted using the RDE e-SIF software on handheld/laptop computers.

Ethylene Gas (C2H4)—a natural hormone that is produced by all plant tissue. It acts as a

ripening agent that helps fruit become colorful and tasty by accelerating leaf and flower

senescence (the wilting, fading, and general decay of plant tissue). Most plants produce ethylene

gas even after they are harvested. When storing or transporting different types of produce in the

same container, it is crucial to consider whether a certain commodity is an ethylene producer or

is ethylene sensitive. For this reason, it is best to select produce that is not overly ripe.

Ethylene Producing Commodity—many fruits such as apples, bananas, and tomatoes show a

strong increase in ethylene levels at the late green or breaker stage. As a consequence of high

ethylene, chlorophyll is degraded and other pigments are produced. This results in the typical

color of the mature fruit peel. When fruits are stored in an enclosed area, ethylene that is

released from ripening and mature fruits accumulates and stimulates late-ripening fruits to

premature ripening ("One rotten apple can ruin the whole basket"). Activity of many maturationrelated enzymes thus increases. Ethylene producers should not be stored or packaged with

ethylene sensitive products because they may cause premature ripening of some products and

may ruin others.
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 3 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Ethylene Sensitive Commodity—generally, unripe produce is sensitive to ethylene gas and will

commence ripening if stored with ethylene-producing commodities. Fruit and vegetables vary in

their degree of ethylene sensitivity.

Extranet—also known as AGNISX, MPO’s Extranet is a browser-based portal site that allows

MPO employees and participating States to share, modify, and discuss information electronically

with users within and outside of USDA. The public does not have access to MPO’s Extranet.

Fact Sheet—a one-page document prepared by the MPO Sampling Manager that summarizes

sample collection and shipping criteria for a specific commodity. Information included in a Fact

Sheet includes: acceptable and unacceptable products or varieties for collection, desired sample

collection size or weight, packaging and shipping instructions, optimum storage/shipping

temperatures, and a statement as to whether the commodity is ethylene sensitive or is an ethylene

producer. Fact Sheets for current MDP and PDP commodities must be made available to all

sample collectors and are posted on MPO’s Extranet site.

FTE—Acronym for Full Time Equivalent. One FTE is equal to 2080 man-hours per year.

Hermetically Sealed—a seal on a bag or container that makes its contents airtight. The means

by which the bag is sealed is by fusion, gasketing, crimping, or equivalent means so that no gas

or vapor can enter or escape.

Internal SOPs—Standard Operating Procedures (SOPs) created by each State Sampling

Manager that provide specific details concerning how a procedure is to be implemented in

his/her particular State. Internal SOPs are intended as a supplement to MPO SOPs, which

represent minimum PDP and MDP requirements and are presented as a general guideline.

Objective Selection/Judgment—a selection process that will yield the same result no matter

who conducts it; free of influence by emotions or personal preferences.

Pallet—a wooden, metal, or plastic framework designed to be picked up by mechanical devices

such as forklift or pallet trucks for the storage and transport of boxed food commodities inside a

warehouse or distribution center. The holding capacity of each pallet varies by commodity and

by interior building design/space.

PDA—Acronym for Personal Digital Assistant. A handheld/palmtop computer also referred to

as a Pocket PC. The RDE e-SIF software works on PDAs that are running the Windows Pocket

PC or Windows Mobile 2003 operating system.
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 4 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Primary Site—the scheduled, preferred site from the State's list of active sites where the sample

should be collected.

Probability Size Measurements—a measure of size for a unit in a collection from which a

sample is to be drawn. The probability of selecting a particular unit for the sample is

proportional to this measure (consequently, it must be known for all units before the sample is

drawn).

Processed Commodity—any food product that has undergone physical or chemical treatment

resulting in a substantial change in the original state of the food. Frozen, canned, and dried foods

are examples of processed commodities.

Proxy Site—a retail store that may be in close proximity to the Primary or Alternate Site and

that receives the product directly from the Primary or Alternate Site (in the distribution chain).

Proxy sites may be used for the collection of PDP commodities and only for MDP commodities

that have been approved by MPO.

Quality Assurance (QA)—an integrated system of activities involving planning, quality control,

quality assessment, reporting, and quality improvement to ensure that a product or service meets

defined standards of quality with a stated level of confidence. The PDP and MDP QA programs

encompass sampling, laboratory analysis, and data reporting/database activities. Quality control

(QC) is defined as the activities that are conducted on a routine/daily basis to carry out quality

assurance (i.e., to reduce error and ensure that data are generated and/or processed within known

and acceptable limits).

Quarterly Sampling Plan—a document that is transmitted via a memo to Sampling Managers

that outlines weekly and monthly schedules for the collection of commodities and provides a

source of information vital to both sample collectors and laboratory personnel on upcoming new

commodities. Timing of drafts and final Quarterly Sampling Plan is as follows:

 45 days prior to beginning of new quarter: MPO draft sent to Sampling Managers for their

review and comments

 30 days prior to beginning of new quarter: MPO final plan sent to Sampling Managers

 15 days prior to beginning of new quarter: each State final sampling schedule posted to

MPO’s Extranet site

Quarterly Sampling Schedules (final)—commodity collection schedules prepared by State

Sampling Managers and approved by appropriate analyzing laboratory Technical Program
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 5 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Managers that list specific sites and dates when PDP and MDP commodities will be collected for

every month in each quarter. State Sampling Managers must post their final schedules to MPO’s

Extranet site two weeks prior to each new quarter.

Quick Reference Guide—a quarterly document created by the MPO Sampling Manager that

serves as a quick reference for sample collectors by providing summaries of: (1) unacceptable

products that cannot be collected and (2) specially requested e-SIF “Must-Have” information.

Both PDP and MDP commodities are included in this document. Current Quick Reference

Guides are posted on MPO’s Extranet site.

Random Selection Process/Procedure—statistics of or characterizing a process of selection in

which each item of a set has an equal probability of being chosen. A system for selecting a

sample of units from a larger collection [statisticians prefer the word "population"] of units in

which every member of the collection has a positive probability of selection.

Refrigerated Temperature—a cooled container that can maintain temperatures between 33-

45oF (1-8oC) for a specified period of time during holding or shipment of commodities to their

respective laboratory.

Relative or Comparative Volume Information—a method used to calculate and show the

differences in the volumes of produce that different vendors or collection sites carry in each

participating State. [not a technical term per se -- if unit A has volume a and unit B volume b,

then if A has relative volume a', B has relative volume a'(b/a).] States are required to update

volume information at least once a year; this information is used by MPO’s NASS statistician to

make monthly site selections for each State.

Remote Data Entry (RDE)—software system used to enter, review, and submit PDP/MDP

data. The RDE system has two major components, a Windows-based system that allows sample

collectors to enter and submit an electronic SIF and a Web-based system that allows laboratories

to enter and submit completed data sets.

Retail Market/Store—a facility in which food is sold directly to the end-user customer.

Sample Information Form-Standardized paper form used by sample collector to capture sample

identity information, such as a unique Sample ID, sample origin, variety, lot number, and postharvest fungicide labeling.

Sample Information Form (SIF)—a form that contains detailed information on a commodity

collected for PDP or MDP that makes each sample (or group of samples-MDP) unique. SIFs
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 6 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

may be in an electronic or paper format and must be emailed or shipped, respectively, for/with

each set of samples.

Semi Annual Program Plan—a statement of work distributed in January and July each year by

MPO for both PDP and MDP programsthat contains the following information: (1)

administrative updates; (2) a list of new and revised SOPs; (3) commodity additions, deletions,

and continuations, including names of laboratories who will be testing the new commodities; (4)

testing additions, deletions, changes, and continuations; and (5) any other future program

directions. The program plans often include the Shipping Assignment Charts for the upcoming

two quarters and an updated MPO Contact List.

Shipping Assignment Chart—a quarterly document created by the MPO Sampling Manager

that contains pertinent collection and shipping information for all the sampling States:

commodity names and codes that are scheduled for collection, State collection numbers, sample

amounts/weights, collection changes from the previous quarter, sample start dates, analyzing

laboratory names and locations, and special collection notes. Current Shipping Assignment

Charts are available on MPO’s Extranet site.

Sample—a group of produce items randomly collected by trained sample collectors from a

box/crate at a specific collection site that has a unique site code and/or grower/packer/distributor

assigned to it.

 For PDP, a specific weight or volume of the desired commodity is selected from a single

box/crate, and is bagged and shipped to a specific laboratory. The single bag containing

all the units of a particular commodity collected on a particular day at a particular facility

is considered a PDP “site” sample. All units in the sample must represent the same lot

number. Each site sample is reported as a separate result in MPO’s database and the PDP

Annual Summary Report.

 For MDP, a commodity sample is comprised of three sub-samples or three groups of

individual units that are selected from a single box/crate. Each sub-sample is individually

bagged, and all three sub-samples are shipped together to a specific laboratory. All subsamples in a box/crate must represent the same lot number. Each sub-sample is reported

as a separate result in MPO’s database and the MDP Annual Summary Report.

Size Measure—comparative volume number to show the size differences in sampling sites.

(See “Relative or Comparative Volume Information”)
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 7 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

State Sampling Manager—a professional of appropriate education, training, experience, or

combination thereof, who is responsible for the conduct of a State's sampling program and who

assures that his/her sample collectors adhere to MPO Sampling Standard Operating Procedures.

Sterile—free of any living microorganisms, pathogenic or non-pathogenic.

Stomacher Bag—a high grade, high strength sterile polyethylene bag that holds food samples

for processing and blending. The specialized bag allows for high impacts at room temperatures.

A stomacher machine is a laboratory instrument that produces homogenized food samples

through the use of mechanical paddles that crush and stir the stomacher bag's contents.

Subjective Selection/Judgment—a selection process that is influenced by emotions or personal

preferences; not objective. (If something is free of subjective judgment, it is not influenced by

emotions or personal preference.)

Tamperproofing—a method used to prevent accidental or intentional alteration of a closed or

sealed package.

Terminal Market—an organized market in a city into which large quantities of agricultural

produce are shipped for distribution and sale, generally to retailers, restaurants, and institutions.

A collection of vendors/wholesalers doing business in the same place.

Vendor—an individual wholesaler (person or agency) who sells food in a terminal market.

Volume Weighting—a way of estimating an aggregate value for a collection of units (e.g., a

total or a proportion) from a sample that counts each sampled unit differently depending on its

relevant size ("volume"). Statistics: a coefficient assigned to elements of a frequency

distribution in order to represent their relative importance. [See “Relative or Comparative

Volume Information.]

Voucher—a method of payment for the purchase of fruit and/or vegetables from a food vendor.

It is a document that acknowledges a liability or provides authorization to pay a debt.

Whirl Pak®—a leak-proof primary sample bag which has twistable tabs near the opening that

can be manipulated to tie and seal the bag once the bag has been "whirled" around on itself

several times.
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 8 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Wholesale Market—a market in which food is sold to retailers, distributors, or other

wholesalers who in turn sell to retail or end-use customers. The sale of goods in quantity to

retailers or jobbers for resale (as opposed to a retail market).
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 9 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

________________________________________ _________________________

Prepared by: Jo Kraemer Date

Sampling Manager, Monitoring Programs Office

8609 Sudley Road, Suite 206

Manassas, VA 20110

(703) 330-2300

________________________________________ __________________________

Approved By: Diana Haynes Date

Technical Director, Monitoring Programs Office

8609 Sudley Road, Suite 206

Manassas, VA 20110

(703) 330-2300

________________________________________ __________________________

Approved By: Martha Lamont Date

Program Administrative Director, Monitoring Programs Office

8609 Sudley Road, Suite 206

Manassas, VA 20110

(703) 330-2300
United States Department of Agriculture

Agricultural Marketing Service, Science & Technology

Pesticide Data Program

SOP No: MDP/PDP SAMP GLOSSARY Page 10 of 10

Title: Glossary of Sampling Terms

Revision: Original Replaces: N/A Effective: 4/29/09

Original

 Created descriptions of selected terms used in PDP and MDP Sampling Standard Operating

Procedures.