Pesticide residues in foods can pose risks if present at unsafe levels. This document discusses pesticide residues, including definitions and classifications of different pesticide types. It also covers factors that influence residue formation, such as application rate and environmental conditions. Risk assessment and monitoring programs set maximum residue limits and estimate exposure and intake to ensure pesticide residues do not exceed safe levels. International and national organizations monitor residues and set limits to protect public health.

1. Pesticide
Residues in
Food
MOZHIARASU S
M.Tech I Year,FSQM

2. Outline
• Introduction- Definitions
• Overview of different classes of pesticides
• Factors influencing the residue formation
• Risk Assessment & Monitoring Programmes on
Pesticide Residues in Food

3. Pesticide & Residues-
Definitions• Biocide by definition is any substance used with the intention
of killing living organisms whether these are pests or not.
• Pesticides are compounds that man uses to control, meaning
to reduce in number or to eradicate, organisms that interact
negatively with his activities such as crop production and
gardening, or to control disease in people, animals, etc.
• Pesticide Residues
Any substance or mixture of substances in food for man or
animals resulting from the use of a pesticide including any
specified derivatives, such as degradation and conversion
products, metabolites, reaction products and impurities
considered to be of toxicological significance.

4. Toxicity LabellingLabel Name Level of
toxicity
Oral lethal dose mg
per kg body weight of
test animal
Listed chemicals
Red label Extremely
toxic
1-50 Monocrotophos, zinc
phosphide, ethyl mercury acetate,
and others.
Yellow label Highly toxic 51-500 Endosulfan, carbaryl,quinalphos,
and others.
Blue label Moderately
toxic
501-5000 Malathion, thiram,glyphosate, and
others.
Green label Slightly toxic More than 5000 Mancozeb, oxyfluorfen, mosquito
repellant oils and liquids, and
most other household
insecticides.
Wikipedia

5. Insectide
• Classification by chemical group
o Organo Chlorine
o Organo Phosphate
o Carbamates
o Pyrethroids

6. Organochlorine
• Organic compound containing at least one covalently
bonded atom of chlorine (the diphenylethanes, the
cyclodienes and the Cyclohexanes)- Highly Effective against
various Insects
• High persistence and Highly lipophilic
DDT
Dicolfol
Methoxychlor
X-Cl Y=H
X=Cl Y=OH
X=OCH3 Y=H
Aldrin Dialdrin
& Endrin
Endosulfan Lindane

7. Organophosphate
• acetylcholinesterase (AChE) in ganglia and in the parasympathetic
nervous system. [SLUD Syndrome]
• Highly Toxic , Less lipophilicity, Fast degradation
• Parathion (parathion-ethyl) introduced in 1944 -higher environmental
stability LD 50:3–13 mg kg−1BW
Common name Rat oral LD50 Rabbit dermal LD50
Chlorpyrifos 96–270 2,000
Diazinon 1,250 2,020
Dimethoate 235 400
Ethoprop 61.5 2.4
Fenamiphos 10.6–24.8 71.5–75.7
Malathion 5,500 >2,000
Methamidophos 13 (female only) 122
Methyl parathion 6 45
Ref,
Mello et al., 2003 : Food Safety:
Comtaminants and toxins

8. Carbamates
• Low toxicity/ Low Lipophilic
• Acetylcholineesterase
Inhibitor (Reversable)
• Common name Rat oral LD50 Rabbit dermal LD50
Aldicarb 1 20
Carbaryl 500–850 >2,000
Carbofuran 8 >3,000
Fenoxycarb 16,800 >2,000
Methiocarb 60–1,000 depending on product >2,000 (rat)
Methomyl 30–34 >2,000
Oxamyl 5.4 2,960
Thiodicarb 66 >2,000

9. Pyrethroids
• Pyrethroids~ Pyrethrin (Tanacetum cinerariae-
folium)
Deltametrin-
LD50 for the fly
is 0.0003 µg
Common name Rat oral LD50 Rabbit dermal LD50
Allethrin 860 11,332
Bifenthrin 375 >2,000
Cyfluthrin 869–1271 >5,000 (rat)
Cyhalothrin 79 632 (rat)
Cypermethrin 250 >2,000
Deltamethrin 31–139 (female) >2,000
Esfenvalerate 451 2,500
Fenpropathrin 70.6–164 >2,000
Fluvalinate 261–282 >20,000
Permethrin 430–4,000 >2,000

10. Benzoylureas
• Synthesized between dichlobenil derivatives and
fenuron
• Act on the formation of chitin,hindering the
development of larvae during moult (by causing
the imperfect formationof the new cuticle) and
causing their death.
• They are not selective , affect CNS of mammals.
• Eg., Diflubenzuron, Flufenoxuron, Hexaflumuron

11. Fungicides
• Inorganic Fungicides-
Copper Salts
• Organic Fungicides in
Table
• DithiocarbomatesEthyl
ene thio urea
• Benzimidazoles- Systemic
Fungicide
• Dicarboximides- Resistant
• Triazoles - biosynthesis of
ergosterol
• Anilinopyrimidines- Act on
biosynthesis of AA
Ref,
Mello et al., 2003 : Food Safety:
Comtaminants and toxins

12. Herbicides
• mechanism of action of
herbicides is an
interaction with the
biochemical processes
of vegetables, they have
no toxicity for animals,
But
• Dermitis
• Paraquat- Toxic to lungs
• Percolate into soil
Ref,
Mello et al., 2003 : Food Safety:
Comtaminants and toxins

13. Formulation of Pesticides
WHY WE NEED
FORMULATION?
• Active Ingredient (AI)
shows activity at low doses
• Even Distribution
• Easy and safe distribution
TYPES OF FORMULATION
• Wettable powders
• Emulsifiable concentrates
• Granules
• Flowable powders
• Microcapsules
Points to remember:
• Dose Precision
• Contaminants
COMPOUNDS USED IN
FORMULATION:
• Adhesive Agent
• Anti Evaporative Agents
• Diluents for solids
• Dispersants
Penetrants
• Solvents
• Surfactants
Ref,
Mello et al., 2003 : Food Safety:
Comtaminants and toxins

14. Factors influencing in formation of
Residues in Food
• Disappearance rate
o Environmental Factors
o Crops
o Enzymatic degradation
o Washing
• Initial deposit
o Application rate
o Formulation
o Application techniques
o Influence of cultivar
o Shape of the cultivar

15. Initial Deposit
• Application rate(Per Hectare): 1st Generation –
1kg/, 2nd Generation – few Hundred Grams, Last
Generation- Few tens of grams
• Formulation: If granules gives progressive absorption
and a distribution effect
Cabras et.al., 1999

16. Application techniques:
• High Micronization in low volumes
Influence of cultivar:
Cabras et.al., 1997

17. Shape of the cultivar
Cabras et.al., 1997

18. Disappearance Rate
Environmental
conditions
• Washing
• Evaporation,
• Co-distillation
• Photodegradti
on

19. Crops
Enzymatic Degradation

20. Washing- rain, washing or irrigation

21. Residues in Processing of Foods:
• 1 l of wine is obtained from 1.5 kg of grapes,
• 1 l ofolive oil from 5 kg of olives
• 1 kg of dried prunes from 3 kg of plums,

22. Risk Assessment & Monitoring Programmes on
Pesticide Residues in Food
• Maximum Residue Limit (MRL)- maximum concentration of a
pesticide residue (expressed as mg/kg) that the CAC recommends be
legally permitted in food commodities and animal feeds
• MRLs recommended by the JMPR
TOXICOLOGICAL DOSSIER:
• ADI (Accetable Daily Intake) derived from
biochemical, metabolic, pharmacological, and toxicological properties
of the pesticide derived from studies of experimental animals and
observations in humans.
• no-observed-adverse-effect level (NOAEL)
ADI= NOAEL/Safety Factor (10 to 1000)
ENVIRONMENTAL DOSIER:
• predicting pesticide residue intake include the residue levels found in
practice, their distribution in the commodity, and the effect on
residues of the various processes used in the preparation of food

23. Exposure assessment:
Exposure to a pesticide residue present, or likely to be present under
GAP should be less than ADI
Risk characterization:
• Theoretical Maximum Daily Intake (TMDI) is used as a convenient screening
tool for assessing dietary intake
• the International Estimated Daily Intake (IEDI) is used to obtain a better
estimate of dietary exposure.
• TMDI and IEDI, the risk characterization is based on an average adult
weighing 60 kg
Ref,
Guidelines for predicting
dietary intake of pesticide
residues, WHO Publication

24. INTERNATIONAL LEVEL

25. National Level
National Estimated Daily Intake differs from IEDI by
• Proportion of crop or commodity treated
• Proportions of crop or commodity produced domestically and imported
• Monitoring and surveillance data
• Total diet studies