Ecological Assessment of Storm Impacts

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Data Collection

Chlorpyrifos

CAS Number: 2921-88-2

Basic Information

The chemical structure of Chlorpyrifos Synonym(s): O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphorothioic acid; O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) phosphorothioate; O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioic acid
Formula: C9H11Cl3NO3PS
 Molecular Weight: 350.584
 Boiling Point (°C): 200
 Melting Point (°C): 42 - 43.5
 Contaminant Type: Chlorpyrifos is an insecticide.
Notes: Colorless or white crystals
Additional Information: In animals, chlopyrifos transforms to chlorpyrifos-oxon, which is about 3000 times as potent against the nervous system as chlorpyrifos itself. a

Solubility (in water)

  • Solubility: 2 mg/l g
    Temperature (°C): 25
  • Solubility: 0.4 mg/l e
    Temperature (°C): 23

Half-Life (in soil unless otherwise noted)

  • t1/2: 22 days e
    Temperature (°C): 25
     pH Value: 8.1
     Environment: Buffered distilled water
  • t1/2: 35 days e
    Temperature (°C): 25
     pH Value: 6.9
     Environment: Buffered distilled water
  • t1/2: 62 days e
    Temperature (°C): 25
     pH Value: 4.7
     Environment: Buffered distilled water
  • t1/2: 60-120 days a
    Environment: Can range from 2 weeks to over one year depending on the soil type, climate, and other conditions
  • t1/2: 17 weeks e
    Environment: Sterile sandy loam at 10 ppm initial concentration
  • t1/2: > 24 weeks e
    Environment: Sterile organic soil at 10 ppm initial concentration
  • t1/2: < 1 weeks e
    Environment: Nonsterile sandy loam at 10 ppm initial concentration
  • t1/2: 2.5 weeks e
    Environment: Nonsterile organic soil at 10 ppm initial concentration

Toxicity Effects

  • Organism Type: Birds g
    Common Name: Hen
     Toxicity: 32 mg/kg
     Test: LD50
  • Organism Type: Crustaceans e
    Scientific Name: Gammarus fasciatus
     Toxicity: 0.32 µg/l
     Test: 96h LC50
  • Organism Type: Crustaceans e
    Scientific Name: Gammarus lacustris
     Toxicity: 0.11 µg/l
     Test: 96h LC50
  • Organism Type: Crustaceans e
    Scientific Name: Gammarus pulex
     Toxicity: 0.05-0.1 µg/l
     Test: 1h LC90-95
  • Organism Type: Crustaceans e
    Common Name: Mysid shrimp
     Scientific Name: Mysidopsis bahia
     Toxicity: 1.7 µg/l
     Test: 96h LC50
  • Organism Type: Crustaceans e
    Common Name: Mysid shrimp
     Scientific Name: Mysidopsis bahia
     Toxicity: 0.37 µg/l
     Test: MATC
  • Organism Type: Crustaceans e
    Common Name: Migrant prawn, oriental shrimp
     Scientific Name: Palaemon macrodactylus
     Toxicity: 0.01; 0.25 µg/l
     Test: 96h LC50
  • Organism Type: Fish g
    Common Name: Goldfish
     Scientific Name: Carassius auratus
     Toxicity: 0.18 mg/l
     Test: 24h LC50
  • Organism Type: Fish e
    Common Name: Shiner perch
     Scientific Name: Cymatogaster aggregata
     Toxicity: 3.5; 3.7 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Sheepshead minnow
     Scientific Name: Cyprinodon variegatus
     Toxicity: 2.3 µg/l
     Test: MATC
  • Organism Type: Fish e
    Common Name: Carp
     Scientific Name: Cyprinus carpio
     Toxicity: 0.13 mg/l
     Test: 48h LC50
  • Organism Type: Fish e
    Common Name: Mummichog
     Scientific Name: Fundulus heteroclitus
    Toxicity: 4.7-12.2 µg/l
     Test: 96h LC50
  • Organism Type: Fish g
    Common Name: Mosquitofish
     Scientific Name: Gambusia affinis
     Toxicity: <1 mg/l
     Test: 24h LC50
  • Organism Type: Fish e
    Common Name: Mosquitofish
     Scientific Name: Gambusia affinis
     Toxicity: 260 µg/l
     Test: 72h LC50,S
  • Organism Type: Fish e
    Common Name: Green sunfish
     Scientific Name: Lepomis cyanellus
     Toxicity: 40 µg/l
     Test: 72h LC50,S
  • Organism Type: Fish e
    Common Name: Bluegill
     Scientific Name: Lepomis macrochirus
     Toxicity: 0.007 mg/l
     Test: 24h LC50,S
  • Organism Type: Fish e
    Common Name: Bluegill
     Scientific Name: Lepomis macrochirus
     Toxicity: 2.6 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Bluegill
     Scientific Name: Lepomis macrochirus
     Toxicity: 0.003 mg/l
     Test: 96h LC50,S
  • Organism Type: Fish e
    Common Name: California grunion
     Scientific Name: Leuresthes tenuis
     Toxicity: 1.3 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: California grunion
     Scientific Name: Leuresthes tenuis
     Toxicity: 1.2 µg/l
     Test: MATC
  • Organism Type: Fish e
    Common Name: Inland silverside, tidewater silverside
     Scientific Name: Menidia beryllina
     Toxicity: 4.2 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Inland silverside, tidewater silverside
     Scientific Name: Menidia beryllina
     Toxicity: 0.54 µg/l
     Test: MATC
  • Organism Type: Fish e
    Common Name: Tidewater silverside
     Scientific Name: Menidia peninsulae
    Toxicity: 1.3 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Tidewater silverside
     Scientific Name: Menidia peninsulae
    Toxicity: 46 µg/l
     Test: MATC
  • Organism Type: Fish e
    Common Name: Gulf toadfish
     Scientific Name: Opsanus beta
     Toxicity: 560 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Gulf toadfish
     Scientific Name: Opsanus beta
     Toxicity: <3.7 µg/l
     Test: MATC
  • Organism Type: Fish e
    Common Name: Fathead minnow
     Scientific Name: Pimephales promelas
     Toxicity: 3.9-7.1 µg/l
     Test: 30d EC50, growth
  • Organism Type: Fish e
    Common Name: Fathead minnow
     Scientific Name: Pimephales promelas
     Toxicity: 7.1 µg/l
     Test: 30d LC50
  • Organism Type: Fish e
    Common Name: Fathead minnow
     Scientific Name: Pimephales promelas
     Toxicity: 122; 200-506 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Columbia River redband trout
     Scientific Name: Salmo gairdneri
     Toxicity: 11 µg/l
     Test: 96h LC50
  • Organism Type: Fish e
    Common Name: Blue tilapia
     Scientific Name: Tilapia aurea
     Toxicity: 418 µg/l
     Test: 24h LC50
  • Organism Type: Fish e
    Common Name: Nile tilapia
     Scientific Name: Tilapia nilotica
     Toxicity: 151 µg/l
     Test: 72h LC50
  • Organism Type: Mammals g
    Common Name: Guinea pig
     Toxicity: 504 mg/kg
     Test: LD50
  • Organism Type: Mammals g
    Common Name: Rat
     Scientific Name: Muridae (Family)
     Toxicity: 96-270 mg/kg
     Test: LD50

Soil Organic Carbon/Water Partition Coefficients

  • Koc: 9930 l/kg x
  • Koc: 3.8 e

Octanol-Water Partition Coefficients

  • Log Kow: 5.11 e
    Formulation: at 20C
  • Log Kow: 4.82; 4.7 e

Resource Map: Click below to open in a new window to view or print.
Potential applications of this contaminant in the St. Johns Water River Management District

Work Cited

a Beyond pesticides fact sheets. Pages retrieved November, 2003 from http://www.beyondpesticides.org. Beyond Pesticides, Washington, DC.
e Verschueren, K. 1996. Handbook of Environmental Data on Organic Chemicals, 3rd edition. John Wiley & Sons, Inc., New York.
g Meister, R. T., and C. Sine (Ed). 2003. Crop Protection Handbook, volume 89. Meister Publishing Company, Willoughby, OH.
x Armbrust, K. L. 2001. Chlorothalonil and chlorpyrifos degradation products in golf course leachate. Pest Management Science 57:797-802.