Fenchlorphos (ISO)

Insecticides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Organophosphate Insecticides

Pesticide (Fenchlorphos (Ronnel)) -> USDA PDB

log Kow= 5.07

4.88

1.49 at 77 °F (NIOSH, 2024) - Denser than water; will sink

1.485 @ 25 °C/4 °C

Relative density (water = 1): 1.48

1.49 at 77 °F

(77 °F): 1.49

COLORLESS CRYSTALS

WHITE CRYSTALLINE POWDER

WHITE TO LIGHT TAN CRYSTALLINE SOLID

Powder or granules

White to light tan, crystalline solid [Note: A liquid above 106 degrees F].

0.004 % at 77 °F (NIOSH, 2024)

IN WATER: 0.004 G/100 ML @ 25 °C; FREELY SOL IN CARBON TETRACHLORIDE, ETHER, METHYLENE CHLORIDE

Readily sol in most organic solvents: in acetone 908, chloroform 347, toluene 592, xylene 503, methanol 25, kerosene 37 (all in g/100 ml)

water solubility = 1 mg/l @ 20 °C

Solubility in water at 20 °C: none

(77 °F): 0.004%

Decomposes (NIOSH, 2024)

97 °C @ 0.013 mbar

BP: decomposes.

decomposes

Decomposes

106 °F (NIOSH, 2024)

41 °C

41 °C

106 °F

106 °F

0.0008 mmHg at 77 °F (NIOSH, 2024)

0.0008 [mmHg]

8X10-4 MM HG @ 25 °C

Vapor pressure, Pa at 25 °C:

0.0008 mmHg

(77 °F): 0.0008 mmHg

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P273, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P273, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

Hazard Traits - Environmental tox

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Not combustible. Liquid formulations containing organic solvents may be flammable. Gives off irritating or toxic fumes (or gases) in a fire.

Ronnel is corrosive to the skin. [AHLS, p. 105] The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline. [TLVs and BEIs]

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Ronnel is found on List B. Case No: 2590; Pesticide type: Insecticide; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): O,O-Dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

Ronnel: Revocation of Tolerances. This document revokes the tolerances for residues of the pesticide ronnel (O,O-dimethyl-O-dimethyl-O-(2,4,5-trichlorophenyl)phosphorothioate) including its 2,4,5-trichlorophenyl containing metabolites, in or on all raw agricultural commodities. EPA is taking this action because all registered uses of ronnel on these commodities have been cancelled, therefore, there is no need to maintain these tolerances.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m.

Vacated 1989 OSHA PEL TWA 10 mg/cu m is still enforced in some states.

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Induce vomiting (ONLY IN CONSCIOUS PERSONS!). Refer for medical attention .

Excerpt from NIOSH Pocket Guide for Ronnel:

(General first aid procedures)

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

... MUST BE STORED IN ITS SEALED ORIGINAL CONTAINERS, IN WELL-AIRED, FRESH & DRYSTOREHOUSES OR IN SHADED & POSSIBLY WELL-AIRED PLACES. IT IS RECOMMENDED THAT THE PRODUCT'S TEMP ... NOT EXCEED 25-30 °C, & KEEP ... AWAY FROM SOURCES OF HEAT FREE FLAMES OR SPARK-GENERATING EQUIPMENT. CONTAINERS MUST BE STACKED IN SUCH A WAY AS TO PERMIT FREE CIRCULATION OF AIR ... AT BOTTOM & INSIDE OF PILES. STORAGE AREAS MUST BE LOCATED AT SUITABLE DISTANCE FROM INHABITED BUILDINGS, ANIMAL SHELTERS, & FOOD STORES; MOREOVER, THEY MUST BE INACCESSIBLE TO UNAUTHORIZED PERSONS, CHILDREN, & DOMESTIC ANIMALS. /PROTHOATE/

1. Ventilate area of spill. 2. Collect spilled material in the most convenient & safe manner & deposit in sealed containers for reclamation, or for disposal in a secured sanitary landfill. Molten ronnel should be absorbed in vermiculite, dry sand, earth, or a similar material.

Ronnel may be disposed of in sealed containers in a secured sanitary landfill.

Fenchlorphos is stable at temp less than or equal to 60 °C and in neutral and acidic media, though hydrolyzed by dilute alkali to the dimethyl cmpd. It is incompatible with alkaline pesticides. Recommendable method: Incineration. Peer-review: Incineration (high temp) in a unit with effluent gas scrubbing is recommendable. (Peer-review conclusions of an IRPTC expert consultation (May 1985))

A) Place the disposal in an open furnace. Add equal parts of sand and crushed limestone, then cover with a combustible solvent (alcohols, benzene, etc). Ignite from a safe distance and burn with the utmost care. B) Place the disposal with sand and crushed limestone into a paper carton. Burn in the furnace with afterburner and alkali scrubber. Recommendable method: Incineration.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations. Do NOT wash away into sewer.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

LD50 Anas platyrhynchos (mallard duck) male oral about 2000 mg/kg, 3 mo old /sample purity 92.5%

LD50 Phasianus colchicus (pheasant) male oral 611 mg/kg (95% confidence limit 351-1063 mg/kg) 3-4 moold /sample purity 92.5%/

LC50 Gammarus fasciatus (scud) 4300 ug/l (95% confidence 3400-5400 ug/l). Static bioassay without aeration, pH 7.2-7.5, water hardness 40-50 mg/l as calcium carbonate and alkalinity of 30-35 mg/l. /Technical material, 95%)

LC50 Salmo gairdneri (rainbow trout) 550 ug/l (95% confidence limit 410-730 ug/l), wt 1.1 g. Static bioassay without aeration, pH 7.2-7.5, water hardness 40-50 mg/l as calcium carbonate and alkalinity of 30-35 mg/l. /Technical material, 95%)

For more Ecotoxicity Values (Complete) data for RONNEL (9 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on photolysis in aqueous solution (estimated half-life at water surface - 9 days(1)), the loss of ronnel from soil due to photolysis by sunlight is probably not important due to the light attentuation by soil(SRC). Hydrolysis of ronnel was not accelerated by sediment-sorption which suggests that soil catalyzed hydrolysis should not be important(2,SRC). The Koc values estimated from water solubility and Kow(3-4), and regression equations(5) indicate that the leaching potential of ronnel from soil is low. Based on its low vapor pressure(3), moderate Henry's Law constant(3) and high Koc value, volatilization should not be important for the dissipation of ronnel from soil(SRC). In soil the biodegradation of ronnel may be fast since the mean half-life in surface waters is 8.4 days(6).

AQUATIC FATE: The hydrolysis half-life of ronnel in distilled water at 35 °C was estimated to be 24 days(1-2). The hydrolysis is faster at alkaline pH(1,7) and the hydrolysis half-life is reduced to 6 hrs in the presence of 0.1 mmole copper (II) catalyst(3). Although ronnel readily photolyses with light of wavelength less than 290, the rate of photolysis is slow in water with natural sunlight(4-5) and the half-life due to sunlight photolysis at near surface of a water body is 17.5 days based on 12 hr daylight(5). Biodegradation of ronnel in surface waters has a mean half-life of 8.4 days and the rate can be accelerated by adding inorganic nutrients to water(6).

AQUATIC FATE: In a sediment sample from the Mississippi River that contained 1.4% organic carbon, 96% of ronnel was found in the sediment-sorbed phase(1). This and the Koc values of 3.64-4.09 estimated from regression equations(3) indicate that ronnel would remain strongly adsorbed to suspended solids and sediment in water. Based on the Henry's Law constant value of 3.2X10-5 atm-cu m/mole estimated from the ratio of the vapor pressure and water solubility(2), volatilization half-life from a model river is estimated to be 1.4 days and from a model pond to be 24.8 days considering the effect of adsorption(2,5,SRC). However, the importance of volatilization from water will substantially decrease due to strong adsorption of ronnel to suspended solid and sediment(SRC). A lipid weight basis bioconcentration factor of 43650 in the guppy (Poecilia reticulata)(4) indicates that bioconcentration of ronnel in aquatic organisms will be important(SRC).

ATMOSPHERIC FATE: A vapor pressure of 7.5X10-5 mm Hg at 20 °C(1) indicates that ronnel may be present partly in the vapor phase and partly in the particulate form in air(2,SRC). Based on an estimation method(3), vapor phase ronnel may be removed from the atmosphere with a half-life of 2.1 hrs due to reaction with photochemically produced hydroxyl radicals(SRC). Partial removal of particulate ronnel from the air may occur by dry deposition(SRC). Particulate ronnel has been found to undergo long distance transport(4).

In a 1968-1969 survey for determining the levels of pesticides in total diet samples, ronnel was detected at a trace concn in a composite grain and cereal sample from Kansas City, MO(1). The estimated total dietary intake of ronnel for U.S. adults were: FY 1978, not detected; FY 1979, 0.001 ug/kg body wt/day; FY 1980, not detected; FY 1981, less than 0.001 ug/kg body wt/day(2). The corresponding dietary intake for infants and toddlers were FY 1978, not detected-less than 0.001 ug/kg body wt/day: FY 1979, not detected; FY 1980, not detected; FY 1981, not detected(3). The daily intake of ronnel for 8 population groups (6-11 months old, 2 yr old, 14-16 yr old male/female, 25-30 yr old male/female and 60-65 yr old male/female) during 1982-1984 were all less than 0.1 ng/kg body wt/day(4). Ronnel was not detected in the 1989 FDA regulatory monitoring survey for pesticides in foods, but was detected in trace amounts in the 1990 regulatory monitoring survey(5-6).

The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.

inhalation, ingestion, skin and/or eye contact

Dizziness. Sweating. Laboured breathing. Unconsciousness. Vomiting. Pupillary constriction, muscle cramp, excessive salivation.

MAY BE ABSORBED!

Abdominal cramps. Diarrhoea. Nausea. Vomiting. Pupillary constriction. Muscle cramps. Excessive salivation.

In Animals: irritation eyes; cholinesterase inhibition; liver, kidney damage

Based on regression equations(3), log Koc values of 3.64 and 4.09 are estimated assuming a water solubility of 1 mg/l at 20 °C(2) and a log Kow value of 4.98(1), respectively(SRC). These log Koc values indicate that ronnel would have a very low mobility in soil(4). Conversely, ronnel would remain strongly adsorbed to sediment and suspended solids in water(SRC). In sediment from Mississippi River that contained 1.4% organic carbon, 96% of ronnel was found in the sediment-sorbed phase(5).

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Ronnel is found on List B. Case No: 2590; Pesticide type: Insecticide; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): O,O-Dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

Ronnel: Revocation of Tolerances. This document revokes the tolerances for residues of the pesticide ronnel (O,O-dimethyl-O-dimethyl-O-(2,4,5-trichlorophenyl)phosphorothioate) including its 2,4,5-trichlorophenyl containing metabolites, in or on all raw agricultural commodities. EPA is taking this action because all registered uses of ronnel on these commodities have been cancelled, therefore, there is no need to maintain these tolerances.

MOST ... /ORGANOPHOSPHATE PESTICIDES/ ARE NOT POTENT INHIBITORS OF ESTERASES UNTIL THEY ARE ACTIVATED IN LIVER ... BY MICROSOMAL OXIDATIVE ENZYMES. /ORGANOPHOSPHORUS PESTICIDES/

Ronnel is a weak inhibitor of cholinesterase. It affects the pseudoesterase of the plasma predominantly, rather than the true acetylcholinesterase of the red blood cells, upon both single and repeated oral doses.

TROLENE & ITS OXYGEN ANALOG WERE HYDROLYZED IN RATS & EXCRETED IN URINE INITIALLY AS PHENYL PHOSPHORIC & PHOSPHOROTHIOIC ACIDS. THESE DECR ... WHILE EXCRETION OF DIMETHYL PHOSPHORIC ACID INCR.

... 42% OF RONNEL AT 100 MG/KG DOSAGE WAS METABOLIZED TO DESMETHYL RONNEL COMPARED TO 6% AT 2 MG/KG DOSAGE. /IN URINE OF RATS AFTER ORAL ADMIN/

TWO PRIMARY PATHWAYS OF APPROX EQUAL IMPORTANCE FOR RONNEL METABOLISM WERE DEMONSTRATED, HYDROLYSIS OF P-O-PHENOL BOND & HYDROLYSIS OF P-O-METHYL BOND TO SECONDARY ESTERS ... .

In vitro studies with preparations from rat brain and liver, indicated the formation of the oxygen analog of ronnel and that this was the source of ronnel toxicity.

For more Metabolism/Metabolites (Complete) data for RONNEL (6 total), please visit the HSDB record page.

AFTER ADMIN OF RADIOACTIVE TROLENE, HIGHEST LEVELS OF TROLENE & ITS DERIVATIVES IN ALL TISSUES WERE REACHED AFTER 12 HR. ... RESIDUES PERSISTING 7 DAYS AFTER ORAL ADMIN WERE SIMILAR FOR TROLENE & ITS OXYGEN ANALOG. TISSUES IN ORDER OF DECR PERSISTENCE ... /WERE/ LIVER, KIDNEY, SPLEEN, SUBCUTANEOUS & MESENTERIC FAT, HEART, BRAIN.

FOLLOWING ABSORPTION FROM GI TRACT, SKIN, OR LUNGS, ORGANOPHOSPHATE PESTICIDES ARE DISTRIBUTED THROUGHOUT BODY. THEY DO NOT ACCUM IN ANY PARTICULAR TISSUE. /ORGANOPHOSPHATE PESTICIDES/

... SIX PESTICIDES (DIAZINON, DIMETHOATE, DISULFOTON, ETHION, PARATHION, & RONNEL) ... /HAVE BEEN RECOVERED/ IN LOW NANOGRAM RANGE FROM SUCH DIVERSE EXTRACTS AS ALFALFA, LETTUCE, MILK ... CHICKENS, HALIBUT, BEES, & URINE.

... FENCHLORPHOS IS STORED IN BODY FAT ... IT IS FOUND IN MILK AFTER ORAL DOSING ... /OF CATTLE/.

Used as an oral or topical medication to kill insects infesting cattle; [ACGIH]

Farming (Pesticides) [Category: Industry]

For Ronnel (USEPA/OPP Pesticide Code: 058301) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

Medication: (Human and Vet). /Former use/

MEDICATION (VET)

The analysis of technical organophosphorus insecticides by (31)P nuclear magnetic resonance showed the major known toxic contaminants to be simple trialkyl phosphorothio- and -dithioic acid esters and the S-alkyl insecticide isomers. Small amt of the bis derivatives & the dithiopyrophosphate were also detected. These contaminants included both byproducts from the synthesis as well as degradation products. This procedure was used to analyze ... technical grade products /including/ ronnel.

(1972) 9.1X10+8 G

(1974) 4.99X10+8 G (CONSUMPTION)

USEPA/OPP Pesticide Code 058301; Trade Names: Korlan, Nankor, Trolene, Viozene, Fenchlorfos, ENT-23284, Blitex, Dermafos, Dow et 14, Dow et 57, Ectoral, ET 14, ET 57, Rovan.

Nankor - 4% dust; Trolene - 15 g boluses- oral for cattle; Korlan (technical grade) - spray; granules - 5% active ingredient; aerosole -2.5% active ingredient; Smear - 5% active ingredient; liquid formulation - 2 lb/active ingredient gal.

EMULSIFIABLE CONCENTRATES

The WHO Recommended Classification of Pesticides by Hazard identifies Fenchlorfos (technical grade) as an active ingredient believed to be obsolete or discontinued for use as a pesticide.

NOT COMPATIBLE WITH ALKALINE MATERIALS SUCH AS LIME SULFUR, LIME OR BORDEAUX MIXTURE.

PRESLAUGHTER WITHDRAWAL TIME FOR DAIRY CATTLE (DAYS) 10. /FROM TABLE/

SINCE FENCHLORPHOS IS STORED IN BODY FAT IT IS RECOMMENDED BY US DEPARTMENT OF AGRICULTURE THAT 60 DAY PERIOD SHOULD ELAPSE BEFORE SLAUGHTER OF TREATED BEEF CATTLE.

Discontinued by Dow Chemical Co.