An introduction to pesticides classification and its maximum residue limits

1. Dr. Sherif Taha
QCAP Egypt
“ ‫الرحمي‬ ‫الرمحن‬ ‫هللا‬ ‫سم‬‫ب‬ ”
Pesticides classification and
maximum residue limits in food

2. CROP LOSS
DOI: E.-C. OERKE, doi:10.1017/S0021859605005708

3. CROP PROTECTION
DOI: E.-C. OERKE, doi:10.1017/S0021859605005708
 pesticide is an “active ingredient ” prevents, destroys, repels, or mitigates a pest, or is a plant
regulator, defoliant, desiccant, or nitrogen stabilizer// Environmental Protection Agency (EPA).
 Food shortage versus the huge current population is the main driving forces to use pesticides
(increase production yield)in agricultural production.
https://esa.un.org/unpd/wpp/Publications/Files/WPP2017_KeyFindings.pdf

4. PESTICIDES
 pesticides have a direct and long-term indirect health impacts,
which result in acute and chronic toxicity, respectively.
 Therefore, all workers that have a direct contact to pesticide
(manufacture, storage, and application) should be with a good
awareness of the dangers of pesticides.
 Application of pesticides on crops shall be under
controlled practices.
 Uncontrolled pesticides practices will not only result in
pesticide-contaminated crops, but also spread
the pesticide contamination risk (soil, water, and air).
https://www.activistpost.com/2012/09/simple-ways-to-avoid-pesticides-in-food.html

5. PESTICIDES CLASSIFICATION BY USE (TARGET AND FUNCTION)
Pesticides
Herbicides Insecticides Fungicides
N N
N
Cl NHCH2CH3
NHCH(CH3)2
Cl CH
CCl3
Cl
S
(CH3
O)2
PS
CO2
CH2
CH3
CHCH2
CO2
CH2
CH3

6. HERBICIDES/ TRIAZINE
 The most commonly used triazine herbicides are;
atrazine (1) which control annual broad-leaved weeds
and
simazine (2) which control most germinating annual grasses
(1) (2)

7. HERBICIDES/ ARYLOXY PHENOXY PROPIONATE
 The most commonly used Aryloxy phenoxy propionate herbicides are;
clodinafop-propargyl (3) which control of annual grasses,
and
fluazifop-butyl (4) which control of annual and perennial grass weeds in
broad-leaved crops.

8. HERBICIDES/ DINITROANILINE
 The most commonly used dinitroaniline herbicides are;
pendimethalin (5) which control of most annual grasses
and trifluralin (6)
(5)
(6)

9. INSECTICIDES/ ORGANOCHLORINES
 Organochlorines pesticides are organic compounds with five or
more chlorine atoms, they have a long-term residual effect in the
environment. It is resistant to most chemical and microbial
degradations.
A well-known example of dichloro diphenyl ethanes organochlorine
insecticides is dichloro-diphenyl trichloro-ethane (pp'-DDT) (7), banned.
Note: DDT may found in contaminated samples by dicofol (8). Where, commercially used
dicofol is usually contaminated by DDT .
(7) (8)

10. INSECTICIDES/ ORGANOPHOSPHORUS
 organophosphorus insecticides are easily decomposed in the
environment by various chemical and biological reactions, thus
organophosphorus insecticides are not persistent in the environment.
 The most commonly used organophosphorus insecticides are;
chlorpyrifos (9) and Diazinon (10)
(9) (10)

11. INSECTICIDES/ CARBAMATE
 Carbamates are cholinesterase inhibitors. Two examples of
carbamate insecticides are; Carbaryl (11) and oxamyl (12).
(11)
(12)

12. FUNGICIDES / OXATHIIN
 The most commonly used oxathiin fungicide are; flutolanil (13)
which control different pathogens on rice, cereals, potatoes,
sugar beet and on different plants and Boscalid(Bd,14)
(14)
(13)

13. FUNGICIDES / TRIAZOLE
 The most commonly used triazole fungicide are;
Propiconazole (15) which is a systemic foliar fungicide with a
broad range of activity, flusilazole (16)
(15)
(16)

14. FUNGICIDES / PHENYL PYRROLE & ANILINOPYRIMIDINE
 Fludioxonil(17) and Cyprodinil(18) are commonly used fungicides
as foliar fungicides.
 Note, same sample may be contaminated by both these
fungicides as they are commercially present together.
(17) (18)

15. PESTICIDES IN LOW INCOME COME COUNTRIES
P. Schreinemachers, P. Tipraqsa, Agricultural pesticides and land use intensification in high, middle and low income countries, Food Policy 37 (2012) 616-626.

16. PESTICIDES CONTROL
 Pesticides shall be controlled during it production stage till its proper intended
application.
 Pesticide control during its manufacturing stage is generally carried out by
Environmental laboratories.
 Other authorities , may Agricultural ones, will control pesticide packaging, labelling,
transportation and storage.
 Laboratories belong to Agricultural department will also ensure that the good
agricultural practices is followed.
 Different laboratories, which may belongs to different authorities, are intended to ensure
food safety once it present in the market, for exportation, and for importing.
 All the above laboratories (except those testing labs for pesticide packaging) are
carrying out pesticide residue analysis.

17. PESTICIDES MAXIMUM RESIDUE LIMITS
 Appling pesticides under good agricultural practices (GAP) doesn’t means
that there aren’t residue of used pesticides in such crops.
 Crops at the pre-harvest stage and before reaching the market shall be
free from pesticide residues or with permitted residue concentrations.
 Maximum Residue Limits (MRLs) of pesticides defined as; the upper legal
levels of a concentration for pesticide residues in or on food or feed based
on good agricultural practices and to ensure the lowest possible consumer
exposure, According to the European Food Safety Authority (EFSA) .
 IN EU, EFSA has determined MRL for more than 1000 pesticides, A
default MRL of 0.01 mg/kg was set for pesticide that not specifically
mentioned in the EU database.

18. MAXIMUM RESIDUE LIMITS (MRLS)
 CXL: are maximum residue limits reported by codex alimentarius
commission
 Good Agricultural Practices (GAP) :are Practices that address
environmental, economic and social sustainability for on-farm processes
and result in safe and quality food and non-food agricultural products
(FAO COAG 2003 GAP paper).
 Acute Reference Dose (ARfD): An estimate of the amount a substance in
food and/or drinking water that can be ingested in a period of 24 h or less
without appreciable health risk to the consumer
 Acceptable Daily Intake (ADI) An estimate of the amount of a substance
in food or drinking water that can be consumed over a lifetime without
presenting an appreciable risk to health (EFSA).

19. IMPORTANT TERMS
 European Food Safety Authority (EFSA), gives independent scientific
advice to risk managers based on risk assessments to the European
Commission (setting MRLs, Reviewing ARfD, and ADI,..).
 Plant protection products (PPPs): are pesticides that are mainly used to
keep crops healthy and prevent them from being destroyed by disease
and infestation. They include herbicides, fungicides, insecticides,
acaricides, plant growth regulators and repellents (EFSA). Using PPP is
more focusing than using pesticides which may have a wider application
than agricultural one.
 More details about MRLs setting and calculation:
-https://ec.europa.eu/food/sites/food/files/plant/docs/pesticides_mrl_guidelines_mrl-setting-proc.pdf
-https://ec.europa.eu/food/sites/food/files/plant/docs/pesticides_mrl_guidelines_app-i.pdf

20. IMPORTANT TERMS
 WHO: World health organization
 FAO: Food and agricultural organization of the United Nations
Joint Meeting on Pesticide Residues(JMPR): annual
meeting of experts from FAO and WHO, It is requested from
Codex Alimentarius Commission (FAO/WHO). JMPR consists from
WHO Core Assessment Group (reviewing ADI, ARfD,..) and FAO
Panel (estimate MRL,..)

24. PESTICIDES MAXIMUM RESIDUE LIMITS

31. Sherif2taha@gmail.com