Basic Pesticide Safety

1
Basic Pesticide Safety

• Presented by
• Mary Ketchersid

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Relative Potential Occupational Pesticide Exposure

• HIGH
• Applicators (various)
• Mixers/Loaders, Flaggers, Fumigators, Animal
  dippers

• MEDIUM
• Applicators (open groundrig), Fumigators

• LOW
• Field, forestry, hospital workers

3
Fieldworker Exposure to Pesticides

• Minimum
• Corn
• Soybean
• Cotton
• Wheat

• Maximum
• Citrus
• Apples
• Tomatoes
• Strawberries
• Vegetables
• Grapes
• Tree crops

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Applicator vs. Fieldworker Exposure
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Toxicology
The discipline that dealswith the adverse
effectsof substances or radiation on living
things.
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Hazard Toxicity x Exposure

• HazardA state or set of circumstancesthat may
  result in an undesired event - the cause of risk.

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Hazard Toxicity x Exposure

• Toxicity
• The measure of the abilityof a substance to
  causeharmful effects.

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Hazard Toxicity x Exposure

• ExposureThe total amount of substance that gets
  in or on an organism route, frequency, and
  duration of exposure are important.

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Measures of Toxicity The Median Lethal Dose

• LD50
• The amount (dose) of a chemical which produces
  death in 50 of a population of test animals to
  which it is administered by any of a variety of
  methods
• mg/kg ppm
• Normally expressed as milligrams of substance per
  kilogram of animal body weight

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Measures of Toxicity The Median Lethal
Concentration

• LC50
• The concentration of a chemical in an environment
  (generally air or water) which produces death in
  50 of an exposed population of test animals in a
  specified time frame
• mg/L
• Normally expressed as milligrams of substance per
  liter of air or water (or as ppm)

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One part per million is

• 1 inch in 16 miles
• 1 minute in two years
• 1 cent in 10,000
• 1 ounce of salt in 31 tons of potato chips
• 1 bad apple in 2,000 barrels of apples

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One part per billion is

• 1 inch in 16,000 miles
• 1 second in 32 years
• 1 cent in 10,000,000
• 1 pinch of salt in 10 tons of potato chips
• 1 bad apple in 2,000,000 barrels of apples

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One part per trillion is

• 1 postage stamp in the area of the city of Dallas
• 1 inch in 16 million miles (more than 600 times
  around the earth)
• 1 second in 320 centuries
• 1 flea on 360 million elephants
• 1 grain of sugar in an Olympic sized pool
• 1 bad apple in 2 billion barrels

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Important Concept

• On the left side of the decimal point (? . )
• 1 trillion is bigger than 1 billion
• 1 billion is bigger than 1 million
• 1 million is bigger than 1 thousand
• On the right side of the decimal point ( . ?)
• 1 part per trillion is smaller than 1 part per
  billion
• 1 part per billion is smaller than 1 part per
  million
• 1 part per million is smaller than 1 part per
  thousand

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Risk

• RiskThe probability that a substance will
  produce harm under specified conditions.
• Risk AssessmentThe process of assigning
  magnitudes and probabilities to adverse effects
  associated with an event.

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Risk

• Exposure
• Dose
• Route
• Duration
• Frequency

• Toxicity
• Nature of the chemical
• Interaction with other chemicals

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Relative Toxicity
Least toxic
Caution Caution Warning
Danger-Poison

• Sugar (sucrose)
• Alcohol
• Glyphosate (Roundup)
• Salt (sodium chloride)
• Malathion
• Aspirin
• Metalaxyl (Ridomil)
• Ammonia
• Arsenic (arsenic acid)
• Nicotine
• Aldicarb (Temik)
• Dioxin (TCDD)
• Botulinum toxin

• 29700
• 14000
• 5600
• 3000
• 1375
• 1000
• 633
• 350
• 48
• 1
• 0.93
• 0.001
• 0 .00001

Most toxic
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Relative Toxicity, rat LD50, mg/kg

• Bifenthrin
• Chlorpyrifos
• Cypermethrin
• Fenvalerate
• Imidacloprid
• Isofenphos
• Permethrin

• 55
• 96
• 247
• 451
• 450
• 20
• 430

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Signal Words

• The relative acute toxicity of a pesticide is
  reflected on the label in the form of a signal
  word
• The (toxicologically) appropriate signal word
  MUST appear on every pesticide label
• The three possible signal words are
• CAUTION
• WARNING
• DANGER

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Signal Word

• Danger 0-50 ppm drop to teaspoon
• Warning 50-500 ppm teaspoon to tablespoon
• Caution 500-5000 ppm tablespoon to pint
• Relative non-toxic more than 5000 ppm

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Remember

• For pesticides less is more when dealing with
  toxicity
• The less you need to cause a toxic effect the
  more toxic the substance is
• Thus an LD50 of 25 mg/kg is more toxic than is
  one of 7,000 mg/kg

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Signal Words CAUTION

• Caution reflects the lowest degree of relative
  toxicity
• All pesticides with an LD50 of greater than 500
  mg/kg must display this word on their label
• Actually includes two groups of pesticides
  those classed by the EPA as Relatively nontoxic
  (gt5,000 mg/kg) and those classed as slightly
  toxic (500 5,000 mg/kg)

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Signal Words Warning

• Warning reflects a moderate degree of relative
  toxicity
• All pesticides with an LD50 more than 50 and up
  to 500 mg/kg must display this word on their
  label
• Pesticides here are classed as moderately toxic

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Signal Words DANGER

• Danger reflects the highest degree of relative
  toxicity
• All pesticides with an LD50 of less than 50
• mg/kg must display this word on their label
• Pesticides here are classed as highly toxic

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POISON!!!

• Legally defined term not just anything you
  dont like
• Some pesticides with an LD50 of 50 mg/kg or less
• Labels must reflect this classification
• Label must have the signal word DANGER plus the
  word POISON
• Label also must display the skull and crossbones
  icon

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Relative toxicity

• Organisms cant differentiate between natural
  and synthetic chemicals
• Synthetic does not mean toxic or poisonous
• Natural does not mean safe or even low risk
• Chemicals must be evaluated in their biological
  context of behavior in organisms
• Mode of action, not source, is the concern of
  toxicologists and informed users of pesticides

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Relative toxicity

• Most herbicides act on biological pathways not
  present in humans
• Most pesticides approved for use have LD50s of 50
  mg/kg or greater they have intermediate or
  relatively low toxicity
• Some of the insecticides used are highly toxic

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Relative toxicity

• Some examples of pesticides and other chemicals
  are given to show relative risk of pesticides in
  the environment in which we live
• This is NOT to trivialize the pesticides
• Always treat them with caution and respect
• But, have a realistic recognition of their
  relative risk in a world of risks

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Relative toxicity Insecticides

• TCDD (Dioxin) 0.1 mg/kg
• Parathion 13.0 mg/kg
• Nicotine 50.0 mg/kg
• Carbaryl 270.0 mg.kg
• Malathion 370.0 mg/kg

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Relative Toxicity Herbicides and Additives

• mg/kg
• Paraquat 95
• 2,4-D 375
• 2,4-DP 532
• Triclopyr 630
• Tebuthiuron 644
• Dicamba 757
• Hexazinone 1,690
• Glyphosate 4,320

• mg/kg
• Limonene 5,000
• Clopyralid gt5,000
• Sulfometuron Met. gt5,000
• Imazapyr gt5,000
• Diesel oil 7,380
• Picloram 8,200
• Fosamine am.. 24,400
• Kerosene 28,000

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Relative Toxicity Comparative information

• Highly toxic chemicals
• 0 50 mg/kg range
• (taste 1 teaspoonful)
• mg/kg
• Botulinus toxin 0.00001
• Dioxin 0.1
• Parathion 13.0
• Strychnine 30.0
• Nicotine 50.0

• Moderately toxic chemicals
• 50- - 500 mg/kg range
• (teaspoonful 1 ounce)
• mg/kg
• Paraquat 95
• Caffeine 200
• Carbaryl 270
• Malathion 370
• 2,4-D 375

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Relative Toxicity Comparative Information

• Slightly toxic chemicals
• 500 5,000 mg/kg range
• (1 ounce 1 pint)
• mg/kg
• 2,4-DP 532
• Triclpoyr 630
• Tebuthiuron 644
• Dicamba 757

• mg/kg
• Formaldehyde 800
• Hexazinone 1,690
• Asprin 1,700
• Vitamin B3 1,700
• Household bleach 2,000
• Table salt 3,750
• Glyphosate 4,320
• etc.

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Relative Toxicity Are all substances toxic?

• YES!
• All are toxic to some quantifiable degree
• Sugar has an LD50 of 30,000 mg/kg
• Partiers favorite ethanol has an LD50 of only
  13,700 mg/kg
• Even water has a recognized LD50 of slightly
  greater than 80,000 mg/kg

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Relative ToxicityThe Last Word

• Pesticides are chemicals introduced into the
  environment to perform a function
• The source of a chemical (synthetic vs. natural)
  is irrelevant when considering its toxicity
• Pesticides should be treated with care and proper
  respect but so should household cleaners,
  gasoline and kerosene, bleaches, paints and all
  other chemicals

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The Dose Makes the Poison
All substances are poisons,the right dose
differentiatesa poison from a remedy. Paracelsu
s (1493 - 1541)
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As Dose Increases, Response Worsens
RESPONSE
Alcohol DOSE
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Exposure Routes
O R A L
D E R M A L
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Means of Exposure to Pesticides

• Oral
• Unwashed Hands
• eating
• smoking
• Unwashed Foods

• Inhalation
• Dusts
• Vapors
• Dermal (Skin eyes)
• Spills and splashes
• Open cuts
• Inadequate protective clothing

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Chemical Absorption by Human Skin
Foot arch 1 Palm 6 X Forearm 8 X Back 12
X Scalp 25 X
Armpit 26 X Forehead 43 X Jaw 93
X Scrotum 300X
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Surface Area Exposed in a Casually Dressed
Individual

• UnclothedSurface
• Face
• Hands
• Forearms
• Back of Neck
• Front of Neck Vof Chest

• Surface PercentArea (sq ft) of Total
• 0.70 22.0
• 0.87 27.6
• 1.30 41.3
• 0.12 3.8
• 0.16 5.1

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Dermal Exposure

• Through the skin
• Hands and forearms are most common
• 97 of all pesticide exposures are dermal

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Dermal Exposure

• Gloves (with long sleeve shirt)
• Reduce exposure 90
• Should be unlined
• Chemically resistant
• NOT leather or cloth

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Exposure to Hands Without Gloves
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Exposure to Hands With Gloves
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Oral Exposure

• Through the mouth
• Mostly occurs because of improper storage

PESTICIDE
46

• Pesticides removed from their original
  containers are the highest cause of pesticide
  poisonings in adults and children.

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Duration of Exposure Can Be
ACUTE
CHRONIC
(weeks or years)
(minutes or hours)
2000
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Acute Toxicity

• Adverse effects
• following brief
• exposure
• to a substance

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Chronic Toxicity

• Adverse effects
• following
• prolonged
• exposure
• to a substance

50
REMEMBER

• Repeated low-level
• exposure to
• chemicals that have
• potential to cause
• long-term effects can
• greatly increase the risk
• of chronic adverse effects.

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Chronic Health Effects Potentially Associated
with Pesticide Exposure

• Cancer
• Reproductive Effects
• Birth Defects
• Nervous System Damage

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Hospitalized Pesticide Poisoningin North
Carolina, 1990-1993

• 61 Insecticides (OP, pyrethrins)
• all groups
• 19 Rodenticides
• adult intentional
• childhood

10Fungicides Herbicides occupational
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Why are some pesticides a greater health risk?
The nervous system of insects and humans have
common characteristics.
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Nervous System

• Nerves communicate by
• electrical signals
• Special proteins called transmitters carry the
  electrical signal across the gap between two
  nerves

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Nervous System

• Other proteins called enzymes, clean out the gap
  so the nerve is ready for the next signal
• Insects and humans have some of the same
  transmitters and enzymes

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Organophosphate (OPs) Carbamate Insecticides

• OPs
• acephate, Orthene
• disulfoton, Di-Syston
• chlorpyrifos, Lorsban
• fonofos, Dyfonate
• malathion, Malathion
• diazinon, Spectracide

Carbamates carbaryl, Sevin aldicarb,
Temik oxamyl, Vydate L carbofuran,
Furadan methomyl, Lannate
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Common Symptomsof OP Carbamate Exposure

• dizziness
• nausea
• vomiting
• diarrhea
• excessive urination

• excessive tears
• excessive sweating
• excessive salivation
• pinpoint pupils (eyes)

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Organophosphates

• Mode of Action
• Irreversible inhibition of acetylcholinesterase
  (AchE)
• Treatment
• Atropine
• 2-PAM (Pralidoximine)
• Supportive therapy

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Carbamates

• Mode of Action
• Reversible inhibition of acetylcholinesterase
  (AchE)
• Treatment
• Atropine
• Supportive therapy

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Monitoring OP/Carbamate Exposure

• Blood cholinesterase analysis
• Baseline determination is important
• Depression of 25 or moreis indicative of
  serious overexposure

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Conditions Confused With Pesticide Poisoning

• Heat stressfatigue, dizziness, severe thirst,
  heavy sweating, altered behavior, headache,
  nausea, chills
• Green tobacco sicknessstomach cramps, nausea,
  vomiting, difficulty breathing, dizziness

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Emergency Response

• Remove the person from exposure
• Follow label orMSDS first aid instructions
• Call 911 or take victim to ER or MD
• Give EMTs label, MSDS exposure information

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First Aid for Pesticide Poisoning
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Spill on Skin

• Remove pesticide and contaminated clothing
  immediately.
• Use liquid soap and dont forget hair and
  fingernails.

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Breathing a Pesticide

• Get to fresh air immediately.
• Get medical help.
• Swallowing a Pesticide
• Rinse mouth repeatedly with water.
• Get medical help - dont induce vomiting without
  first checking the label.

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Eye Exposure

• Rinse with clean water for at least 15 minutes.
• Get medical help.

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Decontamination Kit

• Clean water
• Soap or detergent
• Single use towels (disposable)
• Emergency phone numbers

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Safety Precautions
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Washing and Bathing

• Shower or bathe daily after using pesticides.
• Wash hands before touching anything that goes
  into mouth.
• Do not touch face or genitals before washing
  hands.

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Personal Protective Equipment (PPE)

• Chemical resistant or waterproof gloves
• Chemical resistant or waterproof boots
• Goggles or face shield
• Coveralls (chemical resistant or other)
• Respirator (Dust/Mist or Organic Vapor)
• Chemical resistant hat
• Always Read the Label for Proper PPE

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Personal Protective Equipment (PPE)

• The label is very specific about the PPE required
  for mixing/loading, application, and early entry.
• The label sometimes refers to the EPA Chemical
  Resistance Category Selection Chart for more
  information (next slide).

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EPA Chemical Resistance Category Selection Chart
High Highly chemical resistant. Clean or replace
PPE at end of each days work. Rinse off at rest
breaks. Moderate Moderately chemical resistant.
Clean or replace PPE within an hour or two of
contact. Slight Slightly chemical resistant.
Clean or replace PPE within 10 min. of
contact. None No chemical resistance. Dont use
this type of material as PPE when contact is
possible
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Personal Protective Equipment (PPE) Gloves
Waterproof or chemical resistant gloves (read
the label to determine the correct type)
Never wear leather!
Natural Rubber
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PPE Gloves
Barrier laminate
Butyl Rubber

• If the label says waterproof, you may choose
  gloves made of rubber or synthetic materials.
• If the label says chemical resistant, use the
  selection chart or use barrier laminate, butyl,
  nitrile, neoprene, or Viton ().

Viton
Nitrile Rubber
Neoprene
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PPE Boots
Choose knee-high rubber or synthetic boots
without holes. Wear cuff on outside of boot.
Never wear leather.
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PPE Coveralls

• Coveralls can be reusable
• types (cotton or blends)
• or disposable types such as
• Tyvek? or Kleenguard?.
• The label will specify if
• chemical resistant coveralls
• (coated/waterproof material)
• are needed.

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PPE Eye Protection
Goggles or face shield are required if
label calls for eye protection. Face shield
offers more protection when mixing and loading.
A chemical resistant hat is sometimes specified
on the label.
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PPE Respirators

• Must be made for the pesticide - see the label.
• Make sure it fits correctly - no air gaps
• Change cartridge frequently
• Wash with soap and water after use
• Store in plastic bag after washing

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PPE Respirators

• Chemical cartridge - Most common. NIOSH or MSHA
  approved. Organic vapor cartridges TC-23C or
  TC-14G.

80
PPE Respirators

• Dust/Mist (MSHA/NIOSH TC-21C)
• Reduces exposure to various dusts and mists.
• Label will specify type of respirator.

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Cleaning Contaminated PPE
82
Cleaning Contaminated Clothing

• Wash contaminated clothing daily.
• Do not attempt to clean clothing contaminated
  with undiluted pesticide - throw away.
• Prerinse, dont crowd washer, use hot water
• Use long cycle heavy duty liquid detergent
• Keep separate from other clothing

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Skin Conditions Associatedwith Pesticide Exposure

• Irritation
• Allergy

84
Allergens

• Anything that causes allergies
• Need more than 1 exposure to the product
• After the 1st exposure, the body develops a
  negative response
• When exposed again, the body responses negatively
  
• allergic
  reaction

85
Allergies can

• Trigger an asthma attack
• Cause shock
• Cause rashes, blisters, contact dermatitis
• Cause itchy, watery eyes, sneezing

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Pesticides Associated withAllergic Reactions

• permethrin, Pounce, Ambush
• rotenone, various
• maneb, Maneb
• dazomet, Basamid
• Could be anything !

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Importance of Allergic Reactions

• Permanent
• Worsen with recurrent exposures
• Can be fatal
• Allergy to similar substances

88

• The signs and symptoms of a pesticide poisoning
  are similar to

Heat Stress
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Heat Stress Symptoms

• Exhaustion, headache, nausea, chills, dizzy
• Thirsty and dry mouth
• Clammy skin or hot, dry skin
• Heavy sweating or not sweating
• Confused, slurred speech, irrational
• Death

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Heat Stress Symptoms
Pupils of a heat stress victim are normal
Pupils of an OP pesticide poisoning victim are
pinpoint (constricted)
91
Heat Stress

• Move to shade
• Rapidly cool victim - splash or sponge cool water
  on skin
• Drink as much water as possible
• Stay calm and call for help

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To Minimize Pesticide Exposure

• Know the chemical and associated hazards
• Read and follow the label instructions

93
To Minimize Pesticide Exposure

• Wear Personal Protective Equipment (PPE)
• Mix and load pesticides in a spill containment
  area

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To Minimize Pesticide Exposure

• Use integrated pest management (IPM) techniques
  to minimize pesticide use

95
To Minimize Pesticide Exposure

• Use techniques that minimizesurface and ground
  water contaminationand drift
• Recycle pesticide containers

96
To Minimize Pesticide Exposure

• Comply with intervals for field re-entry
  harvest
• Wash hands before eating, smoking,and using the
  bathroom

97
To Minimize Exposure to Others

• Wash pesticide contaminated clothing separately
• Store mix pesticides in original containers
  labeled mixing equipment - - never in food
  containers
• Lock pesticides away from children

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Any Questions ?

• Contact me at
• 979-845-6531
• 115 Agronomy Field Lab
• 2488 TAMU
• College Station, TX 77843-2488
• m-ketchersid_at_tamu.edu

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Many Thanks for help and information

• W. Gregory Cope NC State
• Julia F. Storm NC State
• Mark Matocha TAMU
• Eric Taylor TAMU