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How Poisonous Are Pesticides

This is a summary of the toxicity of certain insecticides to test animals (usually the white rat) based on the amount of chemical that would need to be eaten at one time to cause death.

Insecticide Acute oral LD50 to rats
(mg/kg)
Approximate ingested lethal dose for humans (concentrated chemical)
aldicarb (Temik) 0.93
Disyston 2.7
oxamyl (Vydate) 4.7 1/70 to 1/5 teaspoonful
fenaminphos (Nemacur) 8
abamectin (Avert) 10
azinphosmethyl (Guthion) 11-13
methomyl (Lannate) 17
endothall 38-51 1/5 to ½ teaspoonful
dichlorvos (DDVP or Vapona) 50
nicotine 50-60
bifenthrin (Talstar) 55
Metasystox R 65-75 ½ to 1-1/2 teaspoonfuls
lambda-Cyhalothrin(Scimitar, Demand) 79
chlorpyrifos (Dursban) 97-276 1-1/2 to 3 teaspoonfuls
fipronil 100
endosulfan (Thiodan) 100
Rotenone 132-1500
trichlorfon (Dylox) 144
imidan 216
cypermethrin (Cynoff, Demon, ) 247-250
2,4-D 375
Diazinon (Knox-out) 300-400
naled (Dibrom) 430
imidacloprid (Merit) 450 3 to 9 teaspoonfuls
cyfluthrin (Tempo) 500
carbaryl (Sevin) 540-800
MSMA 700
acephate (Orthene) 866-945
pendimethalin 1050
malathion 1500
propiconazole (Banner) 1517
DEET (Off) 2000
oxythioquinox (Morestan) 2500
permethrin (Dragnet, Flee) 430-4000 ¼ to 1 cup
glyphosate (Roundup) 5600
dithiopyr (Dimension) >5000
Resmethrin 715-10,200 1-1/2 to over 3 cups
chlorothalonil (Daconil) >10,000
fosamine ammonium (Krenite) 24,000

For more information, please call the Pesticide Management Program at (860) 424-3369 or email the deep.pesticideprogram@ct.gov or write to:

Department of Energy and Environmental Protection
Bureau of Materials Management and Compliance Assurance
Pesticide Management Program
79 Elm Street
Hartford, CT 06106-5127

Pesticide Certification

 Content Last Updated on November 29, 2011