Pesticides Glossary

Introduction

This is an introduction to some of the technical terms we often use. It is designed to help people understand the work we do on pesticides residues, and is aimed at people who may not know much about pesticides or science, but who are interested in residues in food.

We have a separate "A-Z of Pesticides" which lists individual pesticides we refer to in our reports.

If you cannot find the explanation you need, or you think any of our explanations are unclear or misleading, please let us know.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Absorption

The movement of a pesticide from the surrounding environment into an organism through the surface of the organism.

Acceptable Daily Intake (ADI)

One of a number of different values that toxicologists use to work out safe levels for pesticides residues. It is also used in other safety assessments.
It is the amount of a chemical which can be consumed every day for a lifetime in the practical certainty, on the basis of all known facts, that no harm will result. It is expressed in milligrams of the chemical per kilogram of body weight of the consumer. The starting point for the derivation of the ADI is usually the ‘no observed adverse effect level’ (NOAEL) that has been observed in animal studies for toxicity. This is then divided by an uncertainty factor (most often 100) to allow for the possibility that animals may be less sensitive than humans and also to account for possible variation in sensitivity between individuals.
The studies from which NOAELs and hence ADIs are derived take into account any impurities in the pesticide active substance as manufactured, and also any breakdown products of the pesticide.

ACP

See Advisory Committee on Pesticides

Active Substance

The ingredient in a formulated product that makes the product work as a pesticide. For example: glyphosate is the active substance in a number of different formulated products such as Roundup, and Tumbleweed.

Acute Effects (Toxicity)

Acute does not mean serious in this context. Acute effects are those which result from either a single exposure or several exposures over a short period of time (usually less than 24 hours). See also chronic effects .
Toxicologists call effects acute either because they are apparent very soon after exposure and/or because they last for a short period of time. This is the same way that doctors use the word acute about diseases.

Acute Reference Dose (ARfD)

The definition of the ARfD is similar to that of the ADI , but it relates to the amount of a chemical that can be taken in at one meal or on one day without appreciable health risk to the consumer. It is normally derived by applying an appropriate uncertainty factor to the lowest NOAEL in studies that assess acute toxicity or developmental toxicity.

Acute Toxicity

Ability of a substance to cause adverse effects within a short period following dosing or exposure.

ADI

See Acceptable Daily Intake.

Adjuvant

Formulant designed to enhance the activity or other properties of a pesticide mixture.

Adsorption

The accumulation of a pesticide on the surface of an organism. See also absorption

Adverse Effect

A change in an organism which results in the impairment of some function or capacity, or which makes the organism more susceptible to harm.

Advisory Committee on Pesticides

The Advisory Committee on Pesticides (ACP) is an independent scientific advisory committee. It advises the UK government on all aspects of the pesticide regulation in the UK. More information is available on their website: Advisory Committee on Pesticides Website

Aerobic Conditions

Conditions under which molecular oxygen serves as the terminal electron acceptor in respiration or in metabolic oxygenation

Aerosol

System of fine solid or liquid particles (<39 µm diam.) dispersed in a gas. Aerosol cans using an inert compressed propellant are a common means of dispensing insecticides for domestic use. See also nebulisation.

Aged Residue

Pesticide and degradates present in an environmental system after application and following a period long enough to allow transport, adsorption, metabolism, and dissipation processes to alter the distribution and chemical nature of some of the applied pesticide

Agrochemicals

Another word for agricultural chemicals used in crop and food production. Agrochemicals include pesticides, feed additives, veterinary medicines and related compounds

Analytes

The substances that the PRC surveys look for and measure if present. They can be pesticides or the breakdown products of pesticides formed when pesticides are broken down or metabolised

Analytical Range

The measurement range of a test method where the performance has been validated and quality standards such as action limits have been developed

Analytical Standard

Pesticide reference material of high and defined purity (generally >95%) used for preparation of calibration standards in pesticide analysis

AOAC

Association of Official Analytical Chemists

Application

The dose of pesticide which is used on a crop. Also, the act of using the pesticide on the crop.

Application Type

Pesticides are normally applied in one of several ways: sprays, granules, mists, fogs

ARfD

See Acute Reference Dose

ASTM

American Society for Testing and Materials

B

Baby Food, Baby Milk Regulations

Baby milk and foods marketed as meals for babies have special rules limiting all pesticide residues to a very low level
We monitor both as part of our rolling programme

Bait

A food or other substance used to attract a pest to a pesticide or trap where it can be destroyed

Batch

A quantity of material which is produced under uniform conditions

Bioaccumulation

The progressive increase in the amount of a substance in an organism or part of an organism because the organism takes up the substance at a faster rate than it is removed from the organism.

Bioactivation

Transformation of a pesticide within an organism into a more biochemically active metabolite.

Bioavailability

The extent to which a pesticide residue can be taken up into an organism from its food and environment and the rate at which this occurs

Bioconcentration

The process by which the amount of pesticide or other substance is concentrated in an organism

Biodegradation

The conversion or breakdown of the chemical structure of a pesticide by or in organisms. See also Degradation and Mineralisation.

Biological Indicator

Species or group of species which is representative or and typical for a specific status of an ecosystem, which appears frequently enough to serve for monitoring and whose population shows a sensitive response to changes, e.g. the appearance of a pesticide in the ecosystem

Biomass

The total living mass in a defined segment of an ecosystem expressed as the living weight per unit area or mass. Soil microbial biomass is often used as an indication of potential microbial activity level in soil.

Biopesticides

Pesticides of biological origin including pheromones and other semiochemicals , microorganisms such as Bacillus thuringiensis, fungi, protozoa, viruses, viroids), plant extracts such as rotenone and pyrethrum, and other novel alternative products

Breakdown

see Degradation

Breakdown Product

When most chemicals enter the environment they break down into other chemicals. The new chemicals are called breakdown products. When the new chemicals are toxicologically significant they are included in the residue definition for the original pesticide.

Buffer Zone

Distance for environmental protection between the edge of an area where pesticide application is permitted and a sensitive non-target area such as a water course.

C

CAC

Codex Alimentarius Commission

CAS

Chemical Abstracts Service

CCPR

Codex Committee on Pesticide Residues

Chronic Effect

The effects of exposure to a pesticide which arises slowly and as the result of exposure over a long period of time.

Chronic Exposure

Continued exposure occurring over an extended period of time, or a significant fraction of the lifetime of the exposed individuals or test species.

Chronic Toxicity

The capacity for a pesticide to produce injury following chronic exposure, or to produce effects which persist whether or not they occur immediately upon exposure, or are delayed

CIPAC

Collaborative International Pesticide Analytical Council

CLI

CropLife International

Cocktail Effect

See Multiple Residues

Codex Alimentarius Commission (CAC)

The organisation charged with the development of the Codex standards and texts. The Codex Alimentarius Commission is an intergovernmental body jointly sponsored by the Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO). Membership is open to all Member Nations and Associate Members of the FAO and WHO, and currently consists of over 160 countries.

COLEACP (Europe-Africa-Caribbean-Pacific Liaison Committee)

An organisation aiming to promote the competitive export of fresh fruit, vegetables, flowers and ornamental plants from the ACP. Its specialised information and advisory services are open to all ACP companies in the horticultural export sector and are financed by the European Commission. It has two overriding objectives: to enable ACP companies to comply with European food safety and traceability requirements, and to consolidate the position of small-scale producers in the Africa, Caribbean and Pacific horticultural export sectors.

Compliance (GLP)

See GLP compliance statement

Compliance (Residue)

The meeting of official Maximum Residue Level (MRL) standards by residue levels in food consignments sampled and tested by approved methods.

Consumer

In risk assessments, and when referring generally to safety, a consumer is anyone, of any age, who eats or drinks (consumes) the food or drink being checked. It does not mean the person who buys the food.

Consumer Groups

The Risk assessments we publish consider intakes of different consumer groups, based on data from the Food standards Agency (FSA) obtained during the National Dietary and Nutrition Surveys of 1986, 1992/93, 1994/95, 1997 & 2001. The groups are:

• Adults
• Infants
• Toddlers
• Children
• 4-6 year old
• 7-10 year old
• 11-14 year old
• 15-18 year old
• Vegetarians
• Elderly, living in their own home
• Elderly, living in residential accommodation

Control Sample

A sample from a field test plot to which no pesticide was applied or which received chemical treatments identical to the test plots except for the test chemical

Cryogenic Milling

Most of our samples are cryogenically milled as part of the preparation for analysis (testing). This means that the samples are frozen and then ground into a powder while dry ice keeps the sample frozen at a very low temperature.
Preparing samples at room temperature (for instance by blending), can breakdown pesticide residues before they are analysed.

Cumulative Effect

Overall adverse change which occurs when repeated doses of a pesticide have biological consequences which are additive.

D

Decomposition

See Degradation

DEFRA

Department for Environment Food and Rural Affairs

Degradate

The chemical product resulting from the degradation or breakdown of pesticide.

Degradation

The process by which a pesticide is broken down to simpler substances. The process is also referred to as breakdown and as decomposition. See also Biodegradation and Mineralisation.

Desorption

The release of a substance from or through the surface of an organism. The opposite of Adsorption or Absorption.

Detoxification

The chemical processes which make a pesticide less toxic.

Diluent

An inert substance used to dilute

Dissipation

The loss of pesticide residues from a particular environment due to degradation and movement to another environment

Dissipation Time 50%(DT50)

The time required for one half of the initial quantity or concentration of a pesticide to dissipate from a particular environment. See also Half-life.

Dose-Effect Relationship

A graded relationship between the dose of a substance and the magnitude of a defined effect in a population of organisms exposed to the substance.

Dose-Response Relationship

The relationship between the dose of a substance and the incidence of a defined effect in a population of organisms exposed to the substance.

E

EFSA

European Food Safety Authority

Emulsifier

A surfactant used to facilitate dispersion of one liquid in another liquid with which it does not normally mix.

Endpoint

A measurable ecological or toxicological characteristic or parameter of the test system (usually an organism) that is chosen as the most appropriate assessment criterion; such as death in an acute test, or tumour incidence in a chronic study.

Enforcement Method

See Regulatory Method

Enhanced Degradation

The increased rate of degradation of a pesticide in soil or another environment by a population of microorganisms that has adapted to metabolise it through previous exposure to it or a similar chemical. It is also known as accelerated degradation or enhanced biodegradation.

Environmental Risk

The probability that an adverse effect on humans or the environment will be observed for a given exposure to a pesticide, based on the frequency of occurrence and the sensitivity of the system. See also Risk Assessment

EPA

Environment Protection Agency

EPPO

European and Mediterranean Plant Protection Organisation

Estimated Daily Intake (EDI)

A calculation of the likely daily consumption of a pesticide residue, based on the estimated levels of the residue in different foods and the amounts of those foods which are eaten by different groups. The EDI for a particular pesticide and particular food may vary from group to group because different groups may eat different amounts of that food.

Estimated Maximum Daily Intake (EMDI)

A calculation of the maximum possible consumption of a pesticide residue, based on the estimated levels of the residue in different foods and the amounts of those foods which are eaten by different groups, corrected for the reduction or increase in residues resulting from preparation, cooking, or commercial processing

Exposure

The amount of a pesticide that reaches the target population, organism, tissue or cell, usually expressed in numerical terms of concentration, duration and frequency.

Extraneous Residue Limit (ERL)

An ERL refers to a pesticide residue or a contaminant arising from environmental sources (including former agricultural uses) other than the use of a pesticide or a contaminant substance directly or indirectly on the commodity. It is the maximum concentration of a pesticide residue or contaminant that is recommended by the Codex Alimentarius Commission (CAC) to be legally permitted or recognised as acceptable in or on a food, agricultural commodity or animal feed.

F

FAO

Food and Agriculture Organisation of the United Nations

Formulant

Any added material in a pesticide formulation other than the biologically active ingredients. This may include carrier or other substances which enhance the biological activity or physio-chemical properties of the formulation. See also adjuvant, diluent, inert sticker, surfactant, vehicle (CIPAC, 1980).

Formulation

See pesticide formulation

Frozen Storage Stability

see Storage Stability Test

G

GAP

See Good Agricultural Practice

GLP

See Good Laboratory Practice

Good Agricultural Practice (GAP)

The nationally authorised safe uses of pesticides under conditions necessary for effective and reliable pest control (the way products should be used according to the statutory conditions of approval which are stated on the label). GAP encompasses a range of pesticide applications up to the highest authorised rates of use, applied in a manner which leaves a residue which is the smallest practicable. Authorised safe uses are determined at the national level and include nationally registered recommended uses, which take into account public and occupational health and environmental safety considerations. Actual conditions include any stage in the production, storage, transport, distribution and processing of food commodities and animal feed.

Good Experimental Field Practice

The formalised process for designing and recording the practices used in the performance of field investigations with pesticides, and which assure the reliability and integrity of the data. See Good Laboratory Practice.

Good Laboratory Practice (GLP)

The formalised process and conditions under which laboratory studies on pesticides are planned, performed, monitored, recorded, reported and audited. Studies performed under GLP are based on the national regulations of a country and are designed to assure the reliability, and integrity of the studies and associated data.

GCPF

Global Crop Protection Federation (became CropLife International in 2001)

GEMS

Global Environmental Monitoring System

GIFAP

Groupement International des Associations Nationales de Fabricants des Produits Agrochimiques (became GCPF in 1996)

Ground Water

The water present in the saturated subsurface zone of the soil profile, where all open spaces/pores in the sediment and rock are filled with water

Guideline Level

The maximum concentration of a pesticide residue in or on a feed or food commodity, resulting from a use reflecting Good Agricultural Practice, but where an acceptable daily intake has not been estimated.

Guideline Value

The maximum recommended amount of pesticide residue in a particular environment that ensures acceptable air, water or food quality and does not constitute a significant risk to the user.

H

Half-Life

The time taken for the concentration of a pesticide in a particular environment to decline by one half. See also Dissipation Time.

Hazard

The inherent properties of a pesticide which gives potential for adverse effects to man or the environment during its production, use or disposal, depending on the degree of exposure.

Hazard Assessment

The determination of factors controlling the likely effects of a hazard such as mechanism of toxicity, dose effect relationships and''worst case exposure levels. This is the prelude to risk assessment. (US-EPA, 1992)

High Level Consumer

A term used in UK risk assessment calculations to describe the amount of food consumed by a person. In line with internationally agreed approaches, the PRC uses the 97.5th percentile value, which is generally about three times the average amount consumed. This takes account of different eating patterns that may occur throughout the population.

HMI

See Horticultural Marketing Inspectors

Horticultural Marketing Inspectors

Horticultural Marketing Inspectors (HMIs) collect samples for us from wholesale markets and import points, alongside their normal work of enforcing EU marketing standards (e.g. checking that Class 1 produce really is Class 1) for fresh fruit and vegetables. The Horticultural Marketing Inspectorate is part of the Rural Payments Agency .

Hydrolysis

Reaction in which a chemical bond is cleaved and a new bond formed with the oxygen atom of a molecule of water.

I

Identification

The process of unambiguously determining the chemical identity of a pesticide or metabolite in experimental or analytical situations.

Immobilisation

1. A process leading to restricted mobility of a pesticide in plant or soil due to strong binding.

2. The incorporation of pesticide breakdown products into complex organic forms in microbial or plant tissue.

Import Tolerance

An MRL set for imported products where the use of the active substance in a plant protection product on a commodity is not authorised in the European Community (EC), or an existing EC MRL is not sufficient to meet the needs of international trade. All import tolerances are assessed for consumer safety

Imported

The tables in the PRC reports record whether the sample was of UK origin or imported. This can mean different things depending on the commodity. See also 'Origin'.The PRC identify the country from where the produce has been imported only if this is clear from the packaging or labelling.

Impurity

A by-product of the manufacture or storage of a pesticide. Impurities require definition, evaluation and regulation if they are toxicologically significant.

Inert Ingredient

An ingredient in a formulation which by itself does not add materially to the effectiveness of the formulation.

Integrated Pest Management (IPM)

A pest management system that makes use of all suitable techniques and methods in as compatible a manner as possible to maintain the pest populations at levels below those causing economically unacceptable damage or loss.

In-Vitro

Referring to use of cells derived from an organism for use in laboratory studies of biological activity or metabolism or toxicity (Latin for "in-glass")

In-Vivo

The use of the whole living organism in studies of biological activity, metabolism or toxicity (Latin for "within the living")

IPCS

International Programme on Chemical Safety, World Health Organisation

ISO

International Organisation for Standardisation

IUPAC

International Union of Pure and Applied Chemistry

J

JMPR

Joint Food and Agricultural Organisation (FAO)/World Health Organisation (WHO) Meeting on Pesticide Residues which conducts scientific evaluations of pesticide residues in food.

K

L

Laboratory Sample

A sample sent to or received by the laboratory

Leaching

The process by which a pesticide moves downward through the soil profile in the aqueous phase.

Limit of Determination (LOD)

The limit of determination is the lowest concentration of a pesticide residue or contaminant that can be routinely identified and quantitatively measured in a specified food, agricultural commodity, or animal feed with an acceptable degree of certainty by the method of analysis.

Limit of Quantitation

The lowest concentration of a pesticide residue in a defined matrix where positive identification and quantitative measurement can be achieved using a specified method. The term limit of quantitation is preferred to limit of determination to differentiate it from LOD.

Limit of Reporting

The practical limit of residue quantitation at or above the LOQ. The limit of quantitation for a defined matrix and method may vary between laboratories or within the one laboratory from time to time because of different equipment, techniques and reagents.

Lot

The quantity of material which is assumed to be a single population for sampling purposes. See also batch.

Lysimeter

A device for measuring leaching losses from a column or block of soil. The simplest lysimeters may be devices for sampling a portion of the water leaching through a natural sediment or soil, whereas more elaborate lysimeters may involve the confinement of an entire segment of soil from which all leachate is collected.

M

Margin of Safety (MOS)

The ratio of the highest estimated or actual level of exposure to a pesticide and the toxic threshold level (usually the NOEC or NOEL). See also Uncertainty Factor.

Market Basket Survey

Pesticide residue monitoring on a wide range of food items collected from consumer points of sale and in proportions approximating consumption patterns in the local population. Samples are prepared for analysis according to Codex guidelines i.e. minimal preparation. See also total diet study.

Matrix

The material or component sampled for pesticide residue studies.

Maximum Residue Level (MRL)

The maximum concentration of a pesticide residue (expressed as mg/kg) legally permitted in or on food commodities and animal feeds. MRLs are based on good agricultural practice data (GAP), and residues in foods derived from commodities that comply with the respective MRLs are intended to be toxicologically acceptable. MRLs are intended primarily as a check that GAP is being followed and to assist international trade in produce treated with pesticides. MRLs are not in themselves 'safety limits', and exposure to residues in excess of an MRL does not automatically imply a hazard to health. The MRLs applicable in the UK are now set under EC legislation. Website link: Further Information on MRLs

Maximum Residue Level set at the LOD (LOD MRL)

For some pesticides and commodities, insufficient trials data are available on which to set a maximum residue level or there may be no use of the pesticide on that crop. In these cases, the MRL may be set at a default level, i.e. at the limit of determination (LOD) where analytical methods can reasonably detect the presence of the pesticide. These MRLs are not based on Good Agricultural Practice (GAP).

Maximum Residue Limits (Codex or CAC)

In cases where there are no EC MRLs, the acceptability of residues may be judged against Codex Maximum Residue Limits. Although Codex limits are not legally binding, they are taken as presumptive standards. These limits give an indication of the likely highest residue that should occur in edible crops. These are based on worldwide uses and the residues trials data to support those uses, at the time of evaluation (date of setting the limits is specified and thus the Maximum Residue Limit applicable up to that year, but will not take into account subsequent approved uses.)

There are occasions where the MRL that has been set by Codex may not reflect current UK Good Agricultural Practice such as with the Codex MRLs for dithiocarbamates and propamocarb on lettuce. In such circumstances it is possible to exceed the Codex MRL through a UK approved use. This factor needs to be taken into account when assessing results.

Maximum Tolerated Dose (MTD)

The highest dose of a pesticide in chronic toxicity testing that is expected to produce only limited toxicity when administered for the duration of the test period.

Measurement Uncertainty

Measurement uncertainty is a complicated issue, but at the core is a familiar problem. When something is measured, even with very accurate instruments, that measurement will never be exact due to limitations in either the measuring method or the measuring instrument. These limitations can be very small but they will still be present. Measurement uncertainty is therefore an indication of how accurately the measured value actually reflects the actual value of what is being measured

For pesticide residues, measurement uncertainty is important because a residue level might be measured at just over the MRL, whereas it might actually be just under the MRL. This means that we can only be certain that a residue level is over the MRL if it is greater than the MRL plus the measurement uncertainty. For most pesticide residues, the measurement uncertainty is 50% of the MRL.

Metabolism

Sum total of all physical and chemical processes that take place within an organism; in a narrower sense, the physical and chemical changes that occur for a pesticide within an organism. It includes uptake and distribution within the body, changes (biodegradation), and elimination of pesticides and their metabolites.

Metabolite

The set of all the chemical reactions that go on inside a living plant or animal is called its metabolism. When chemicals are broken down by metabolisms, any new chemicals produced inside the plant or animal are metabolites.

Pesticide metabolites can be as important toxicologically as the parent (original) pesticide. So they are often included in the legal definition of the pesticide residue and measured alongside the parent (original) pesticide. See also Breakdown Product.

Mg/Kg

Mg/kg means milligrams per kilogram, and is the unit of measurement we use to measure pesticides in food. When we say we found 1 mg/kg of a pesticide in a food, this means that for every kilogram of food we tested we found 1 mg of pesticide.

There are 1000 milligrams in a gram, and 1000 grams in a kilogram. So there are a million (one thousand, thousand) milligrams in a kilogram. Another way of expressing milligrams per kilogram is parts per million so 1 milligram per kilogram is one part per million.

Mg/Kg Bw/Day

Mg/kg bw/day means milligrams per kilogram of bodyweight per day. This is the unit of measurement used for Acute Reference Doses (ARfDs).

Microbials

The data submitted for the approval of a pesticide containing a microbial that is new to the UK/EU must be sufficient to allow a full risk assessment to be performed. The data requirements you need to address are not as extensive as those set for chemical active substances but take into account specific factors for microbials e.g. pathogenicity/infectivity in humans and animals, sensitisation of users, the production of toxins and the potential for multiplication in the environment. (Directive 2001/36/EC of 16 May 2001).

Mineralisation

The conversion of an element from an organic form to an inorganic form. Mineralisation of pesticides most commonly refers to the microbial degradation to carbon dioxide as a terminal metabolite. See also immobilisation. See also Biodegradation and Degradation.

Mode of Action

The way in which a pesticide works at a biological or chemical level. Toxicological mode of action means the way in which a chemical causes adverse effects at a biochemical level.

Model

The way in which a pesticide works at a biological or chemical level. Toxicological mode of action means the way in which a chemical causes adverse effects at a biochemical level.

MRL Exceedance

When a residue is found in a food at a level higher than the MRL for that residue in that food.

MRL Exceedances and the relationship with the Acceptable Daily Intake (ADI)

Before permitting any use of a pesticide, a detailed assessment is made to ensure that residues in foods derived from commodities comply with MRLs and will not give rise to unacceptable risks to consumers. MRLs do take account of consumer safety aspects and, in effect, are set at levels below safety limits. However, MRLs must not be confused with safety limits, which are expressed in terms of the acceptable daily intake (ADI) of a particular pesticide residue from all sources. The ADI (expressed as mg/kg bw/day) is the amount of chemical that can be consumed every day of an individual's entire lifetime in the practical certainty, on the basis of all known facts, that no harm will result. See ADI for further information. Whenever unexpectedly high or unusual residues occur during monitoring, the risk to consumers, from exposure to residues at the highest levels found, is assessed by comparison of predicted intakes with the ADI or ARfD as appropriate.

Multiple Residues

Where crops are treated with more than one pesticide, or the pesticide contains more than one active ingredient, it is not unusual to find multiple residues present in samples.

Multiresidue Methods

Analytical method which measures a number of pesticide residues simultaneously.

N

None Were Detected Above the Set Reporting Limit

This term is used in the Brand Name Annex, where no residues were found above their reporting limit.

Nebulisation

Formation of an aerosol of very small liquid particles (fog) or solid particles (smoke) from a pesticide formulation, generally for fumigation of an enclosed space such as a glass-house.

NEDI: National Estimate of Daily Intake

An estimate of intake of pesticide in the diet over the long-term to compare to the ADI . The NEDI is based on median or mean residue levels and a high level consumption (97.5th percentile value) for the daily amounts of the food item consumed over the long term. For further details on the calculation of NEDIs please refer to section 3 of the data requirements handbook on the CRD website.

NESTI: National Estimate of Short Term Intake

NESTI: National Estimate of Short Term Intake

An estimate of peak intake of pesticide in the diet to compare to the ARfD. The NESTI is based on the highest residue found multiplied by a variability factor (see glossary description) and a high level consumption (97.5th percentile value) for the amount of the food item consumed over a single day. For further details on the calculation of NESTIs please refer to section 3 of the data requirements handbook on the CRD website

Neurotoxicity

Neurotoxins are chemicals which interfere with the nervous system in some way. At sufficient doses they can cause paralysis, usually resulting in death, while lower doses might result in altered behaviour.

No MRL

For certain pesticides, an MRL may not have been set. This is not now a common situation.

No Observed Adverse Effect Level (NOAEL)

The highest level of continual exposure to a chemical which causes no significant adverse effect on morphology, biochemistry, functional capacity, growth, development or life span of individuals of the target species which may be animal or human.

other Novel Alternative Products

As the description suggests these are potential products which do not easily sit within a specific category, and as such the data requirements will have to be assessed on a case by case basis

An organism other than the intended target of a pesticide which might be affected by that pesticide.

No-Observable Effect Concentration /Level (NOEC/NOEL

The highest concentration or amount of pesticide in the test system that causes no observable biological effect to the target organism.

O

OC

Organochlorine pesticide. A generic term for pesticides containing chlorine but commonly used to refer to older persistent materials including aldrin, BHC, chlordane, DDT, dieldrin, heptachlor, lindane and toxaphene.

OECD

Organisation for Economic Co-Operation and Development

OP

Organophosphorus pesticide. A generic term for pesticides containing phosphorus but commonly used to refer to insecticides consisting of cholinesterase inhibiting esters of phosphate or thiophosphate.

Origin

The brand name annex in a PRC report identifies the origins of the samples tested. This can mean different things depending on the commodity. For example, butter is often labelled as 'UK origin'; however, the majority of it comes in bulk from New Zealand and is split into smaller blocks and packaged in the UK. Lettuce is fresh produce and 'UK origin' usually means that it has been grown and packaged in the UK. Processed commodities such as cereal bars often contain multiple raw ingredients, each of which may come from a different source/origin. Therefore, the origin of the produce usually reflects the place where it was manufactured. The PRC report the origin as stated on the packaging or labelling of the commodity concerned, unless other more accurate information is available to indicate that the origin is from elsewhere. Some products are listed as 'unknown origin' because the labelling does not give this information.

P

PAN

Pesticide Action Network

Parts per Billion (PPB)

Ratio of amounts expressed as parts of pesticide per 1,000,000,000 parts of sample. This is also expressed as µg/kg. Strictly speaking, the quantities should be the same eg weight to weight (solids) or volume to volume (liquids or gases).

It is also commonly used to describe ratios involving weight to volume but to avoid confusion here it is better to use µg/l.

Parts per Million (PPM)

Ratio of amounts expressed as parts of pesticide per 1,000,000 parts of sample. This is also expressed as mg/kg.

As with Parts Per Billion, it is better to use mg/l to describe ratios involving weight to volume.

Permitted Level (PL)

The permitted levels (expressed as mg/kg), in specific commodities, of some substances which can be classified as pesticides but are controlled under the Miscellaneous Food Additives Regulations 1995 (SI 1995 No 3187).

Persistent Organic Pollutant (POPs)

POPs are chemicals which do not break down easily in the environment. This means that the amounts in the environment can increase over time. Certain POPs can build up in living tissues therefore strict controls are placed on their use. POPs include certain organochlorine pesticides such as DDT.

Persistence

The extent to which a pesticide remains in a particular environment.

Pest

An organism that attacks food and other materials essential to mankind or which affects human beings adversely.

Pesticide

Any substance, preparation or organism prepared or used for controlling or destroying a pest. The majority of pesticides sought by the PRC in its monitoring are those used to control pests in agricultural crops, although non-agricultural products may be included where there is a specific reason for doing so, e.g. where there are implications in terms of possible intakes of residues.

'Pesticide' is a broad term, covering a range of products that are used to control pests. The slug pellets, ant powder, weed killers, and rat and mouse baits used in everyday life are all pesticides. Other types of pesticide include:

• insect killers (insecticides)
• mould and fungi killers (fungicides)
• weed killers (herbicides)
• slug pellets (molluscicides)
• plant growth regulators
• bird and animal repellents, and
• rat and mouse killers (rodenticides)

Often people only think of pesticides as chemicals, but they include many different types of products. Some are natural, such as pyrethrum which is obtained from chrysanthemums, while others are synthetic versions of natural chemicals. A fuller definition of the word 'pesticide' can be found in the legislation that sets out the arrangements for the approval of pesticides.

Pesticide Chemical Name

The scientific name of a pesticide according to an accepted naming convention such as the recommendations of the International Union of Physical and Analytical Chemists (IUPAC), or the Chemical Abstracts Services (CAS) Registry.eg. 2-chloroethyltrimethylammonium.

Pesticide Common Name

A simple name assigned to a pesticide by the International Organisation for Standardisation (ISO) to be used as a generic or non-proprietary name. eg. Chlormequat. A list of all pesticide common names, together with technical details of the pesticides themselves, can be found in the online Compendium of Pesticide Common Names at http://www.alanwood.net/pesticides/index.html.

Pesticide Formulation

The combination of active substances and other ingredients that make up the end-user product.

Pesticide Residue

The traces of a pesticide which remains in or on a feed or food commodity, or soil, air or water following use of the pesticide. For regulatory purposes it includes the parent compound and any specified derivatives such as degradation and conversion products, metabolites and impurities considered to be of toxicological significance.

Pesticide Residue Definition

The pesticide, its metabolites, derivatives and related compounds to which the maximum residue limit (MRL) applies, as specified by Codex or a national regulatory authority.

Pesticide Residue Enforcement

Pesticide residue monitoring programme where the intention is regulatory action against non-complying consignments.

Pesticide Residue Monitoring

The sampling and analysis of pesticide residues in biological and environmental samples taken according to pre-arranged schedules

Pesticide Residues Committee

An independent committee established in 2000 which advises Ministers and the Chief Executives of the Food Standards Agency (FSA) and the Chemicals Regulation Directorate (CRD) on the monitoring programme for pesticide residues in food and drink.

Pesticide Trade Name

The proprietary name assigned to a pesticide or its formulations by the company manufacturing or selling it.

Phloem

The part of the plant's vascular system which transports the products of photosynthesis from the leaves to the rest of the plant.

Photolysis

A chemical reaction caused by light in which the bonds between atoms in a chemical compound are broken, resulting in the breakdown of the compound.

Photosynthesis

The process by which carbon dioxide (from the air) and water (from the soil) are combined under the influence of light to form complex sugars in a plant

Plant Growth Regulator (PGR)

A naturally occurring or synthetic substance which influences but has no nutritive value

Plant Protection Product

The term used in European legislation to refer to pesticides used to protect plants and their products after harvest, or to control unwanted plants. Typically, plant protection products are used in agriculture, horticulture, forestry and industrial and amenity situations, and in domestic gardens and on allotments

If a pesticide is used for purposes other than to protect or control plants, it will usually be considered to be a biocide.

Post-Emergence

The period after a specific crop or pest has appeared. See also Pre-Emergence.

PRC

See Pesticides Residues Committee.

Pre-Emergence

The period before a specific crop or pest has emerged. See also Post-Emergence.

Preferential Flow

Leaching phenomenon whereby water and a dissolved pesticide percolating down through the soil profile move more rapidly through soil macropores or sand/gravel lens than through the network-of-smaller-pores in-the bulk soil.

Pre-Harvest Interval (PHI)

The time interval between the last application of a pesticide to a crop and harvest. See also Withholding Period.

Prior Informed Consent (PIC)

Agreement of the designated national authority in a participating country required before international shipment of a chemical, which is banned or severely restricted in order to protect human health or the environment, can proceed

Probabilistic Modelling

The usual estimates of consumer exposure use single high values for both consumption amounts and residue levels. Whilst these are based on realistic UK dietary survey data and residue levels, they tend to overestimate most representative intakes. This is because they do not take into account actual variations in both amounts consumed and residue levels. Probabilistic modelling is a technique that considers all the possible different combinations of consumption and residue levels. This provides information on the probability of particular intakes occurring.

Processed Food

The food products resulting from the application of physical, chemical or biological processes, or combinations of these, to a primary food commodity, and intended for sale to the consumer or for use as an ingredient in the manufacture of a food product or for further processing.

Pheromones and other Semiochemicals

See Semiochemicals

Plant Extracts

There is a large spectrum of plant extracts, i.e. unprocessed extracts representing a 'cluster of substances' or highly refined containing one active substance. In addition the risk associated with the use of plant extracts may vary between low and very high risk, for this reason they are assessed on a case by case basis

Q

R

Rapid Alert System for Food and Feed

The European Commission runs the Rapid Alert System for Food and Feed (RASFF) which was set up in 1992. Individual member states notify the Commission about any food safety issues they have found and the Commission circulates these to all Member States as Rapid Alerts (popularly known as RASFFs, pronounced ras-efs, after the name of the system).

RASFFs are circulated when risk assessments show intakes are found at levels above the ARfD or ADI. Because MRLs are trading levels, not safety levels, RASFFs are not issued when residues over the relevant MRLs are found.

If the PRC monitoring programme identifies residues where the predicted intakes for one or more of the consumer groups are above the ARfD or ADI, PSD informs the Food Standards Agency which then informs the Commission.

Relatively few Rapid Alerts are about pesticide residues in food. Other topics covered include:

• E coli in meat
• the use of unapproved food additives (such as Sudan Red)
• unacceptable levels of aflatoxins in nuts.

RASFF

See Rapid Alert System for Food and Feed

Raw Agricultural Commodity

The part of a crop used as a food or feed commodity directly from the harvested crop without processing.

Raw Data

The laboratory records and documentation created by the original activities and observations in a GLP study.

Recovery, Analytical

The fraction or percentage of a pesticide residue which can be recovered from a sample during analysis

Registration

The process whereby the responsible national government authority approves the sale and use of a pesticide following the evaluation of scientific data demonstrating that the pesticide is effective for the purposes intended and poses no significant risks to human health, animals or the environment.

Regulatory Method

A validated analytical method which can be applied using commonly available laboratory equipment and instrumentation. A regulatory method has the precision, specificity, limit of determination, etc, needed to test compliance with the regulations.

Relationship Between GAP and MRLs

The MRL can be defined as the maximum concentration of a pesticide residue (expressed as mg/kg) likely to occur in or on food commodities and animal feeds, after the use of the pesticide according to Good Agricultural Practice.

Reporting Limit

The reporting limit is the lowest calibrated level employed during analysis to detect residues. The reporting limit may vary slightly from laboratory to laboratory depending on the equipment available and operating procedures used.

Residue

The small amounts of pesticides present in vegetable and animal products following the application of pesticides. They may not only include the pesticide that was applied but also degradation or reaction products and metabolites that may be of toxicological significance. The levels or amounts of residues present are expressed in milligrams of the chemical in a kilogram of crop/food/commodity (mg/kg), or parts per million.

Resistance

Sometimes when pesticides are used repeatedly to control specific pests or diseases, those pests and diseases can develop tolerance of a pesticide, generally through natural selection, which makes the pesticide less effective. For this reason, some pesticides carry restrictions on the label which limit the number of times it may be used against a particular pest.

Retention Sample

A sample which is stored for a specified period in case of a need for re-evaluation of data obtained from the main laboratory samples

Risk

The probability of any specific hazard occurring from exposure to a pesticide under specific conditions. Risk is a function of the likelihood of exposure and the likelihood of harm to biological or other systems. See also Hazard.

Risk Assessment

The process of defining the risk associated with the use of a pesticide. It is usually expressed as a numerical probability, or as a margin of safety, and involves identifying any hazards, assessing the likely exposure of individuals and groups, and calculating the relationship between the exposure dose and any responses, or effects, in those exposed.

Risk assessments are carried out when residues are found in foods to determine whether, at the levels found, they present a concern for consumer health or not. Consumer risk assessments are routinely conducted as part of the approval process for pesticides, and are based on residue trials. A pesticide will only be approved for use if any risks to consumers are acceptable.

Risk Management

The decision-making process and procedures used by regulators and others to limit potential risks from the use of pesticides. This involves risk assessment, emission control, exposure control and evaluation of the success of the risk mitigation efforts.

Rolling Programme

The PRC has a rolling programme of surveys for lower priority foods

Rotational Crops

Two or more crops grown in sequence to make better use of resources (leguminous crops such as peas and beans fix nitrogen into the soil which can benefit following crops) or to control the build up of pests which would result from the continued growing of the same crop on the same site.

Run-Off

1. The movement of a pesticide from a treated field by surface water and eroding sediment.

2. The loss of formulation off foliage during spray application, particularly at high volume.

S

Safener

A substance added to a pesticide formulation to eliminate or reduce phytotoxic effects of the pesticide to certain crops. See also Adjuvant.

Safety Factor

A value used in the extrapolation from experimental animal studies to the population (in general). For PRC assessments, this represents a value applied to the NOAEL to derive an ADI or ARfD . The value depends on the nature of the effect, the dose-response relationship, and the quality of the toxicological information available. The use of such a factor accounts for possible differences in susceptibility between the animal species tested and humans, and for variation between different individuals in the population. The terms 'safety margin', 'uncertainty factor', and 'assessment factor' are also sometimes used as alternatives to 'safety factor'. The PRC uses the term 'safety factor'.

Sample

A portion of material selected from a larger quantity of material so that it is representative of the whole quantity. For the PRC programme, the samples are as designated in the EC's 'sampling' Directive 2002/63/EC. Examples are: apple - at least 10 apples weighing at least 1 kg; grapes - at least 5 bunches, weighing at least 2 kg.

Sampling Plan

Predetermined procedure for the collection of samples for analysis

Semiochemicals (including Pheromones)

Semiochemicals are chemicals emitted by plants, animals and other organisms - and synthetic analogues of such substances - that evoke a behavioural or physiological response in individuals or the same or other species. Products marketed for use as traps are pesticide products and require an approval by the CRD before they can be marketed. For detailed information on which products do or do not fall within the scope of the relevant legislation Directive 91/414/EEC please see Regulatory Update 10/2006.

Soil Incorporation

The application of a pesticide to soil by mixing or injection into the soil body.

Soil Organic Matter

The organic fraction of the soil, including both fresh and older material (humus) of biological origin.

Sorption

Removal of pesticide from solution by soil or sediment via mechanisms of adsorption and absorption.

Specific Off-Label Approval (SOLA)

For many reasons, label recommendations of approved pesticides do not cover the control of every problem which may arise. This is particularly true for crops that are grown on a comparatively small scale in the UK, as well as for sporadic pests and diseases. It is for this reason that the extrapolations presented in the Long Term Arrangements for Extension of Use have been developed. If these do not address particular needs, growers or their representatives may apply to PSD for a specific off-label approval (SOLA).

Spray Drift

The movement of pesticide spray as airborne droplets or vapour away from the target area during aerial or ground-based spraying operations.

Spreader

See Wetting Agent

Sticker

A substance which increases the adhesiveness of a formulation applied to a surface. It may be part of the formulation or added at the point of application in a tank mix. See also Wetting Agent.

Storage Stability Test

For a pesticide formulation, a test which measures the chemical and physical stability of the product stored under defined, often worst case, conditions. For pesticide residues, a test which measures stability of residues in stored analytical samples, usually held under frozen conditions at a specified temperature.

Surfactant

A formulant for reducing surface tension, thereby increasing the emulsifying, spreading, dispersability or wetting properties of liquids or solids

Surveillance

Systematic sampling and residue analysis of commodities, and collation and interpretation of data, in order to ensure compliance with established MRLs. Surveillance may be directed at domestic, imported or exported commodities.

Suspension Concentrate

Formulation in which the active ingredient is in the form of a stable dispersion of fine particles in water or organic liquid.

Synergist

Substance, which, while formally inactive or weakly active, can significantly enhance the activity of the active ingredient in a formulation.

Systemic Pesticide

A pesticide that can be translocated to sites other than where it was absorbed, in sufficient quantities to be biologically effective.

T

Target

Any organism, organ, tissue, cell or cell constituent that is subject to the action of a pesticide or its residue.

Technical Exceedance

When an MRL has been set at the LOD because there have been no data to support a higher level. In the context of this report, 'technical exceedances' always relate to produce from third countries.

Technical Material

The Commercial grade of the pesticide as it comes from the manufacturing plant, consisting of the active ingredient and any associated impurities, together with small quantities of additives necessary for stability

Theoretical Maximum Daily Intake (TMDI)

A prediction of the maximum daily intake of a pesticide residue, based on the assumption that levels of residues in food are at the Maximum Residue Limits and on the average daily consumption of food per person. The TMDI is expressed in milligrams of residue per person.

Threshold

The concentration of a pesticide in an organism or particular environment below which an adverse effect is not expected

Tolerable Daily Intake

The term preferred by the European Commission for the acceptable daily intake of environmental contaminants. ADI is reserved for pesticides and food additives where extensive toxicological test data is available.

Tolerance, Residue

See Maximum Residue Limits

Total Diet Study

The monitoring of pesticide residues to establish the pattern of residue intake by a person consuming a defined diet. Primary sampling is as for a market basket survey but the samples are further processed as for domestic consumption by trimming and cooking as appropriate to local practice.

Toxicologically Significant

Toxicological significance reflects the extent to which a substance has a toxicological effect.

Toxicology

Toxicology is the science of adverse effects of chemicals on living organisms (plants and animals).

Translocation

The movement of a substance within a system or organism

Transpiration

The evaporation of water from a plant through its leaves

Types of Pesticide

U

UN

United Nations

UNEP

United Nations Environment Programme

Ultra Low Volume (ULV) Spray

Signifies that the total volume rate of spray application is very low (5 litres per hectare or less). ULV pesticide formulations are generally specially developed for the purpose and are applied undiluted.

Uncertainty Factor

The factor in toxicological assessment for extrapolating data from the results obtained from experimental animals to man (assuming that man may be more sensitive) or from selected individuals to the general population. For example an uncertainty factor is generally applied to the no-observed effect level to derive an acceptable daily intake.

V

Validation

In pesticide analysis, the process for establishing that an analytical method or equipment will provide reliable and reproducible results

Variability Factor

A value that describes the variation in residue levels between the highest unit level and the average level in samples made up of many units. Internationally this is agreed to be the 97.5th percentile unit residue level divided by the average of the sum. The variability factor multiplied by the measured residue level from a composite sample (a sample made up by mixing several units before analysis) gives an estimate of the likely higher residue levels that may have occurred in individual units. These estimated higher levels are used in short-term risk assessments involving fruit and vegetables where consumers eat only a portion of a single item such as melon, or a small number of items such as apples or potatoes.

Volatilisation

The evaporation of a pesticide into the atmosphere from a solid or liquid form.

W

Ware

Ware potatoes, sometimes referred to as main crop potatoes, are harvested between August and November, and are available throughout the period August to June because they are stored under controlled temperature after October.

Watershed

The geographical boundaries which divide one water/river catchment area from another

Wetting Agent

A surfactant for use in spray formulations to assist dispersion of a powder in the diluent or spreading of spray droplets on surfaces. It may also incorporate some of the functions of a sticker.

WHO

World Health Organisation of the United Nations

Withholding Period

The minimum permissible time between the last application of a pesticide to a crop (including pasture) and harvesting for human consumption or grazing with livestock. It is also the minimum permissible time between the final application of a pesticide to an animal and the collection of eggs or milk, or slaughter, for human consumption. See also Pre-Harvest Interval.

X

Xylem

The part of the plant's vascular system which transports water and dissolved nutrients from the roots to other parts of the plant.

Y

Z