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Pesticide Safety & Toxicity

Pesticide Safety & Toxicity. Dave Moorhead Warnell School of Forest Resources University of Georgia. Insecticides Nurseries Seed Orchards Plantations Fungicides Nurseries Plantations. Herbicides Nurseries Plantations Repellents Worker use Animal use .

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Pesticide Safety & Toxicity

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  1. Pesticide Safety & Toxicity Dave Moorhead Warnell School of Forest Resources University of Georgia

  2. InsecticidesNurseries Seed Orchards Plantations Fungicides Nurseries Plantations HerbicidesNurseries Plantations Repellents Worker use Animal use Pesticides:Chemicals to control unwanted forms of life - Pests

  3. Relative Toxicity • Organisms can’t 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 • Pesticides should be treated with care and proper respect – but so should household cleaners, gasoline and kerosene, bleaches,paints and all other chemicals Mistretta USFS R-8

  4. “I WANT A SPRAY THAT KILLS EVERYTHING BUT ISN’T DANGEROUS.”

  5. Relative Toxicity:Are all substances toxic? YES! • All are toxic to some quantifiable degree • Sugar has an LD50 of 30,000 mg/kg • Ethanol has an LD50 of only 13,700 mg/kg • Even water has a recognized LD50 of slightly greater than 80,000 mg/kg

  6. Pesticide Toxicity Toxicity -measure of ability of a chemical to injure /kill Exposure -contact with chemical Hazard - degree of exposure & toxicity level LD50 - lethal dose to kill 50% of test animals

  7. Pesticide Toxicity Acute toxicity -injury/death from one exposure Chronic toxicity -injury/death after long-term exposure Oral toxicity - injury/death from swallowing chemical Dermal toxicity- injury/death from exposure to skin

  8. Pesticide Toxicity PPM (parts per million) -1 oz in 62,500 lbs or 1 tbs in 3,906 gal PPB (parts per billion) -1000 times less than ppm - 1 tbs in 3,906,000 gal Half-life - time for 1/2 of initial concentration to be degraded Volatility - ability of a liquid to evaporate

  9. Parts per Millionppm 1 liter of water = 1 kg 1 mg / kg = 1 ppm 1mm3 / liter = 1 ppm 1 mg / liter = 1 ppm

  10. 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 Mistretta USFS R-8

  11. 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 lob in 1,200,000 tennis matches • 1 bad apple in 2,000,000 barrels of apples Mistretta USFS R-8

  12. 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 Mistretta USFS R-8

  13. 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 Mistretta USFS R-8

  14. Signal WordsDANGER “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” Mistretta USFS R-8

  15. Signal WordsWARNING “Warning” reflects an intermediate degree of relative toxicity All pesticides with an LD50 of greater than 50 and less than 500 mg/kg must display this word on their label Pesticides in this category are classed as “moderately toxic” Mistretta USFS R-8

  16. Signal WordsCAUTION “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

  17. POISON!!! • Legally defined term – not just anything you don’t like • Any pesticide 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 Mistretta USFS R-8

  18. Toxicities of Forest Pesticides

  19. Pesticide Toxicity • Toxicity decreases when mixed (diluted) with water • 1 gallon of pesticide in 1 gallon of water is 50% less toxic • 1 gallon of pesticide in 20 gallons of water is 95% less toxic

  20. LD50s of field formulationsGarlon 4 • Garlon 4 --LD50 = 1,419 mg/kg • Streamline uses a 17% solution of Garlon 4 => 1,419 / 0.17 = 8,347 mg/kg • Foliar spray is normally done as a 3% solution => 1,419 / 0.03 = 47,300 mg/kg Mistretta USFS R-8

  21. Relative Acute Toxicity • Garlon 4 1,581 mg/kg Rainbow trout 0.74 mg/L Bluegill 0.87 mg/L • Garlon 3A 2,574 mg/kg Rainbow trout 117 mg/L Bluegill 148 mg/L • Roundup, Glypro Plus >5,000 mg/kg Rainbow trout 8.2 mg/L Bluegill 5.8 mg/L • Accord, Rodeo >5,000 mg/kg Rainbow trout >1,000 mg/L Bluegill >1,000 mg/L

  22. Tordon RUP? Tordon is a very low-risk herbicide with regard to human health **High risk of off-site movement** Great potential to damage non-target plants over an **extended period of time** Mistretta USFS R-8

  23. Picloram PERSISTENCE AND BREAKDOWN Persistent in soil; half-life may be 1 year or more, but it is typically 90 days or less in the South in favorable conditions Breakdown is by photolysis Mistretta USFS R-8

  24. Picloram SOIL ACTIVITY AND MOBILITY Soil active; highly mobile in soil especially if percolating water is present Tends to be excreted by plant roots; results in soil activity even when applied by injection or other cut-surface treatments Mistretta USFS R-8

  25. The Pesticide LabelInformation & Instructions • Precautionary Statements & Warnings • Application, Storage & Disposal • Chemical Formulation

  26. The Pesticide LabelRead 4 Times! • Before Buying the Pesticide • Before Preparing the Material for Use • Before Mixing &Applying • Before Storing or Disposing the Pesticide

  27. Handling Herbicides

  28. Storage, Transport, & DisposalStorage • Approved designated storage area Locked Warning-Pesticides-Keep Out Fire-resistant Containment Ventilation Inventory

  29. Storage, Transport, & Disposal Transport • Check for damaged containers • Transport only needed amounts • Do not transport in passenger section • Secure containers • Prevent over-heating

  30. Secure herbicide containers when transporting

  31. Storage, Transport, & Disposal Spill Procedures • Administer first aid • Contain spill • Contact manufacturer • Dispose of contaminated absorbent

  32. Mixing, Handling , & Applying PesticidesMixing & Handling • Handling Concentrated Forms • Personal Protection Equipment Gloves Eye Protection Clothing • Specific Mixing Recommendations

  33. BE CAREFUL WHEN OPENING HERBICIDE CONTAINERS ESPECIALLY HOT ONES

  34. If Accidental Exposure Occurs: Immediately Wash Thoroughly With Soap & Water

  35. Carry two emergency eye wash bottles

  36. What to Do if a Herbicide Accident Occurs • Treat injury first • Check eyes for contamination & wash out immediately • Remove contaminated clothing & wash off herbicides • Take a copy of label & Material Safety Data Sheet to Doctor • Notify supervisor

  37. Mixing, Handling , & Applying PesticidesApplication • PPE, Water & Detergent • Calibration Check • Prescribed Cleaning Rinsing • Protect Water Supplies!

  38. Storage, Transport, & DisposalDisposal • Estimate job requirements • Mix to avoid excess volume • Triple rinse & dispose/recycle empty containers

  39. Protecting the EnvironmentConcerns • Off-site application • Off-site movement in air • Off-site movement in water • Pesticide persistence

  40. Off-site Movement Generalizations • More clay and organics = less leaching • Higher temperature = more volatilization • Lower relative humidity = more volatilization • Higher wind speed = more volatilization and drift • Nearer to moving water = higher probability of contamination and off-site movement • Finer droplets = more movement Mistretta USFS R-8

  41. Hotter temperature = faster breakdown Higher relative humidity = faster breakdown More microbes = faster breakdown pH effect = chemical dependant More slope = more runoff Breakdown Generalizations Mistretta USFS R-8

  42. Georgia’s Forestry BMPsBMPs for Chemical Applications • Establish appropriate SMZ along perennial & intermittent streams & flowing bodies of water • Consider weather conditions (temperature, wind speed & precipitation) equipment capabilities & pesticide formulations to avoid pesticide drift into the SMZ • Conduct all on-site pesticide handling, such as tank mixing, loading & rinsing equipment away from streams, ponds, wells, & roadside ditches

  43. Georgia’s Forestry BMPsBMPs for Chemical Applications • Dispose of pesticide containers &/or excess pesticides according to local, State & Federal regulations & label requirements • Clean up &/or contain all pesticide spills immediately • Report spills to GA EPD Emergency Response Program 1-800-241-4113

  44. Georgia’s Forestry BMPsPractices to Avoid During Chemical Applications • Applying a pesticide directly to water bodies (streams, lakes, and swamps) unless it is specifically prescribed & labeled for aquatic management • Broadcast applications of pesticides in SMZs

  45. On-Line References Pesticide Applicator Training Course USDA Forest Service Region 8 www.bugwood.org

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