Parathion

H300: Fatal if swallowed [Danger Acute toxicity, oral]

H311: Toxic in contact with skin [Danger Acute toxicity, dermal]

H330: Fatal if inhaled [Danger Acute toxicity, inhalation]

H372 **: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P319, P320, P321, P330, P361+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]

H310 (14.6%): Fatal in contact with skin [Danger Acute toxicity, dermal]

H311 (85.4%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H330 (100%): Fatal if inhaled [Danger Acute toxicity, inhalation]

H372 (100%): Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

Aggregated GHS information provided per 48 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H310: Fatal in contact with skin [Danger Acute toxicity, dermal]

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H351: Suspected of causing cancer [Warning Carcinogenicity]

H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

P203, P260, P262, P264, P264+P265, P270, P271, P273, P280, P284, P301+P316, P302+P352, P304+P340, P305+P351+P338, P308+P316, P316, P318, P319, P320, P321, P330, P337+P317, P361+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

H316: Causes mild skin irritation [Warning Skin corrosion/irritation]

P203, P260, P262, P264, P264+P265, P270, P271, P280, P284, P301+P316, P302+P352, P304+P340, P305+P351+P338, P308+P316, P316, P318, P319, P320, P321, P330, P332+P317, P337+P317, P361+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Artificial respiration may be needed. 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.

Give a slurry of activated charcoal in water to drink. Refer for medical attention .

CAUTION: Parathion is a cholinestorase inhibitor. It has been reported that as little as one drop of parathion can endanger life if splashed in the eye. Toxicity is highest by inhalation.

Signs and Symptoms of Acute Parathion Exposure: Acute exposure to parathion may produce the following signs and symptoms: pinpoint pupils, blurred vision, headache, dizziness, muscle spasms, and profound weakness. Vomiting, diarrhea, abdominal pain, seizures, and coma may also occur. The heart rate may decrease following oral exposure or increase following dermal exposure. Hypotension (low blood pressure) is not uncommon. Respiratory symptoms include dyspnea (shortness of breath), respiratory depression, and respiratory paralysis. Psychosis may occur.

Emergency Life-Support Procedures: Acute exposure to parathion may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:

1. Move victims to fresh air. Emergency personnel should avoid self-exposure to parathion.

2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

4. Transport to a health care facility.

Dermal/Eye Exposure:

1. Remove victims from exposure. Emergency personnel should avoid self- exposure to parathion.

3. Remove contaminated clothing as soon as possible.

4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.

5. Wash exposed skin areas three times with soap and water.

6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

7. Transport to a health care facility.

Ingestion Exposure:

1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.

2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.

3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of parathion is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step

4.Ipecac should not be administered to children under 6 months of age.Warning: Ingestion of parathion may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step

4.The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal.

4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.

5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.

6. Transport to a health care facility. (EPA, 1998)

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly.

Breathing: Respiratory support

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

Use water spray to keep fire-exposed containers cool. If a leak or spill has not ignited, use water spray to disperse vapors and to provide protection for firefighters. Water spray may be used to flush spills away from exposures. Fight advanced or massive fires from a safe distance or from a protected location. Special protective clothing should be worn; normal protective clothing may be penetrated.

Use water spray, dry chemical, foam, or carbon dioxide. (EPA, 1998)

Use water spray, dry powder, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective.

Self contained breathing apparatus with a full facepiece operated in pressure demand, or other positive pressure mode /should be used in firefighting/.

If material /is/ on fire or /is/ involved in fire, extinguish fire using agent suitable for type of surrounding fire. ... Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use foam, dry chemical, or carbon dioxide. /Parathion and compressed gas mixture/

If material /is/ on fire or involved in fire, extinguish fire using agent suitable for type of surrounding fire. ... Use water in flooding quantities as fog. Use "alcohol" foam, dry chemical or carbon dioxide. /Parathion mixture, dry/

If material /is/ on fire or involved in fire, do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may be ineffective. Use "alcohol" foam, dry chemical or carbon dioxide. /Parathion mixture, liquid/

High pressure water hoses may scatter parathion from broken containers, increasing the contamination hazard.

Excerpt from ERG Guide 152 [Substances - Toxic (Combustible)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Collect leaking liquid in sealable containers. Treat remaining liquid with an alkaline substance. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

1. VENTILATE AREA OF SPILL OR LEAK. 2. COLLECT FOR RECLAMATION, OR ABSORB IN VERMICULITE, DRY SAND, EARTH, OR A SIMILAR MATERIAL.

If material is not on fire & is not involved in fire ... build dikes to contain flow as necessary. Attempt to stop leak if ... /it can be done/ without hazard. ... If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location & weather conditions.

Air spill: Apply water spray to knock down vapors.

Spills of parathion on floors ... absorbed with an absorbing clay. Sweeping compound ... facilitate the removal of all visible traces of parathion contaminated clay.

For more Cleanup Methods (Complete) data for PARATHION (9 total), please visit the HSDB record page.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P089, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Potential candidate for rotary kiln incineration, with a temperature range of 820 to 1,600 °C and a residence time of seconds. Also, a potential candidate for fluidized bed incineration, with a temperature range of 450 to 980 °C, and a residence time of seconds. Also, a potential candidate for liquid injection incineration with a temperature range of 650 to 1,600 °C, and a residence time of 0.1 to 2 seconds.

The following wastewater treatment technologies have been investigated for parathion: Reverse osmosis.

At the end of the work day the protective clothes should be removed and a shower taken before returning to street clothes. If clothing becomes contaminated with parathion, it should be immediately removed and a shower taken without delay. ... Smoking or eating should not be permitted when handling parathion until all outer working clothing is removed and the hands and face are washed.

Hydrogen peroxide or hypochlorous acid (dilute) should be available to decontaminate badly contaminated clothing before it /is to be/ laundered.

If material is not on fire & is not involved in fire; keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. ... Avoid breathing vapors. Keep upwind. Avoid bodily contact with the material. Wear appropriate chemical protective clothing. Do not handle broken packages without protective equipment.

Where there is any possibility of exposure of an employee's body to parathion, facilities for quick drenching of the body should be provided within the immediate work area for emergency use. ... Clothing which has had any possibility of being contaminated with parathion should be placed in closed containers for storage until it can be discarded, or until provision is made for the removal of parathion from the clothing. If the clothing is to be laundered, or otherwise cleaned to remove the parathion, the person performing the operation should be informed of parathion's hazardous properties. ... Where there is any possibility that employee's eyes may be exposed to parathion, an eye wash fountain should be provided within the immediate work area for emergency use.

For more Preventive Measures (Complete) data for PARATHION (19 total), please visit the HSDB record page.

In case of leaks or spills, special protective clothing should be worn. Use water spray to disperse vapors and flush spills away. Ventilate area of spill or leak. Spills may be absorbed in vermiculite, dry sand, earth, or a similar material. (EPA, 1998)

Provision to contain effluent from fire extinguishing. Separated from strong oxidants and food and feedstuffs. Well closed. Keep in a well-ventilated room.

All parathion containers shall be protected from ... corrosion, mechanical damage, and sources of ignition. ... Outdoor storage facilities shall be located at least 20 feet from any dwellings, or a populated area and shall be equipped with a sprinkler system, where feasible.

Pesticides containers must be provided with labels indicating the degree of toxicity of the product they contain. The labels must not only give a short description of how to use the prepn, but also state basic precautions to be taken when applying it. /Organophosphorus pesticides/

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Total p-nitrophenol in urine = 0.5 mg/g' Sample at end of shift; [ACGIH, 2020]]

0.1 [mg/m3], inhalable fraction[German Research Foundation (DFG)]

AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: mg/m3)

AEGL 2: Irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape (Unit: mg/m3)

AEGL 3: Life-threatening health effects or death (Unit: mg/m3)

2.8 mg/m3

3.6 mg/m3

1.9 mg/m3

2.5 mg/m3

1.5 mg/m3

2.0 mg/m3

0.96 mg/m3

1.3 mg/m3

0.48 mg/m3

0.63 mg/m3

NOTE THAT VALUES ARE IN mg/m3 , NOT ppm.

AEGLs Status: Interim

0.14 [mg/m3]

1.5 [mg/m3]

2.0 [mg/m3]

0.05 mg/m³

TWA 0.05 mg/m3 [skin]

0.1 [mg/m3]

0.1 mg/m³

TWA 0.1 mg/m3 [skin]

10 mg/m3 (NIOSH, 2024)

10.0 [mg/m3]

10 mg/cu m

10 mg/m³

10 mg/m3

See: 56382

0.05 [mg/m3], inhalable fraction and vapor

8 hr Time Weighted Avg (TWA): 0.05 mg/cu m, skin. /Inhalable fraction and vapor/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.

A4; Not classifiable as a human carcinogen.

Biological Exposure Index (BEI): Determinant: total p-nitrophenol in urine; Sampling Time: end of shift; BEI: 0.5 mg/g creatinine. The determinant is nonspecific, since it is also observed after exposure to other chemicals.

Biological Exposure Index (BEI): Determinant: cholinesterase activity in red cells; Sampling Time: discretionary; BEI: 70% of individual's baseline. The determinant may be present in biological specimens collected from subjects who have not been occupationally exposed, at a concentration which could affect interpretation of the result. Such background concentrations are incorporated in the BEI value. The determinant is nonspecific, since it is also observed after exposure to other chemicals. The biological determinant is an indicator of exposure to the chemical, but the quantitative interpretation of the measurement is ambiguous. These determinants should be used as a screening test if a quantitative test is not practical or as a confirmatory test if the quantitative test is not specific and the origin of the determinant is in question.

0.05 mg/m

(inhalable fraction): 0.1 mg/m

PERMISSIBLE LEVELS OF PARATHION IN WORKING ENVIRONMENT IN 14 COUNTRIES BY REGULATION OR RECOMMENDED GUIDELINES: AUSTRALIA 1978 CEILING 0.1 MG/CU M GUIDELINE; BELGIUM 1978 CEILING 0.1 MG/CU M REGULATION; BULGARIA 1971 MAXIMUM 0.05 MG/CU M REGULATION; FINLAND 1975 CEILING 0.1 MG/CU M REGULATION; FEDERAL REPUBLIC OF GERMANY 1979 TWA 0.1 MG/CU M GUIDELINE; HUNGARY 1974 TWA 0.05 MG/CU M REGULATION; ITALY 1978 TWA 0.1 MG/CU M GUIDELINE; JAPAN 1978 CEILING 0.1 MG/CU M GUIDELINE; THE NETHERLANDS 1978 CEILING 0.1 MG/CU M GUIDELINE; ROMANIA 1975 TWA 0.05 MG/CU M REGULATION; SWITZERLAND 1978 TWA 0.1 MG/CU M REGULATION; USSR 1977 MAXIMUM 0.05 MG/CU M REGULATION; YUGOSLAVIA 1971 CEILING 0.1 MG/CU M REGULATION; ACGIH 1981 TWA 0.1 MG/CU M GUIDELINE. /FROM TABLE/

Parathion is a deep brown to yellow liquid with a faint odor of garlic. It is an organic phosphate insecticide which acts as an inhibitor of cholinesterase, and as such it is highly toxic by all routes of exposure. It may be found as a liquid or as a dry mixture where the liquid is absorbed onto a dry carrier.

Pale-yellow to dark-brown liquid with a garlic-like odor. [Note: A solid below 43 degrees F.] [NIOSH]

PALE YELLOW-TO-BROWN (TECHNICAL-GRADE PRODUCT) LIQUID WITH CHARACTERISTIC ODOUR.

Pale-yellow to dark-brown liquid with a garlic-like odor.

Pale-yellow to dark-brown liquid with a garlic-like odor. [Note: A solid below 43 °F. Pesticide that may be absorbed on a dry carrier.]

The pure material is a yellowish liquid at temperatures above 6 °C

Pale-yellow to dark-brown liquid ... [Note: A solid below 43 degrees F. Pesticide that may be absorbed on a dry carrier].

Pale yellow liquid

Deep brown to yellow liquid

Usually has a faint odor

... Garlic-like odor ...

Phenol-like odor

707 °F at 760 mmHg (EPA, 1998)

375 °C AT 760 MM HG

375 °C @760 [mm Hg]

43 °F (EPA, 1998)

248 to 320 °F (EPA, 1998)

FLASH POINT AT 120-160 °C UNTIL FLAMMABLE IMPURITIES OF TECHNICAL MATERIALS ARE REMOVED ...

248-320F

(oc) 392 °F

less than 1 mg/mL at 73 °F (NTP, 1992)

PRACTICALLY INSOL IN PETROLEUM ETHER, KEROSENE, & USUAL SPRAY OILS

COMPLETELY SOL IN ALCOHOLS, ESTERS, ETHERS, KETONES, AROMATIC HYDROCARBONS, ANIMAL & VEGETABLE OILS

SOL IN CHLOROFORM

Water solubility = 11 mg/l @ 20 °C

Completely miscible with most organic solvents, e.g. dichloromethane >200, isopropanol, toluene, hexane 50 to 100 (all in g/l at 20 °C).

0.011 mg/mL

Solubility in water, g/100ml at 25 °C: 0.002

1.26 (EPA, 1998) - Denser than water; will sink

1.26 AT 25 °C/4 °C

Relative density (water = 1): 1.26

1.2681 @ 20°C

3.78e-05 mmHg at 68 °F (EPA, 1998)

0.00004 [mmHg]

6.68X10-6 mm Hg @ 20 °C

0.00004 mmHg

Log Kow= 3.83

Henry's Law constant = 0.0302 Pa/cu m mole

STABLE IN DISTILLED WATER IN ACID SOLN; HYDROLYZED IN PRESENCE OF ALKALINE MATERIAL & SLOWLY DECOMP IN AIR.

Temperatures above 100 °C (212 °F) may cause decomposition so that containers may burst.

Slightly soluble in water.

Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic

Sulfonates, Phosphonates, and Thiophosphonates, Organic

Light-yellow liquid, it turns solid at 6 °C, a deadly poison by all routes. Organic phosphate insecticide, acts as an inhibitor of cholinesterase. Violent reaction when used as solvent to dissolve endrin. When heated to decomposition it emits very toxic fumes of oxides of sulfur, phosphorus, and nitrogen [Lewis, 3rd ed., 1993, p. 984].

Strong oxidizers, alkaline materials.

Violent reaction with endrin. Highly dangerous; shock can shatter the container, releasing the contents.

While a mixture of parathion & endrin were being blended into a petroleum solvent an exothermic reaction occurred which caused some of the solvent to vaporize. The solvent vapor-air mixture exploded. Overheating, possibly caused by mechanical agitation started the exothermic reaction.

Strong oxidizers, alkaline materials

CDC-ATSDR Toxicological Profile

Parathion is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

Parathion

Pesticide

Listed as Ethyl Parathion

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

Classification of carcinogenicity: 1) evidence in humans: no adequate data; 2) evidence in animals: limited. Overall summary evaluation of carcinogenic risk to humans is Group 3: The agent is not classifiable as to its carcinogenicity to humans. /From table/

Cancer Classification: Group C Possible Human Carcinogen

CLASSIFICATION: C; possible human carcinogen. BASIS FOR CLASSIFICATION: Increased adrenal cortical tumors in female and male Osborne-Mendel rats and positive trends for thyroid follicular adenomas and pancreatic islet-cell carcinomas in male rats in one study. HUMAN CARCINOGENICITY DATA: None. ANIMAL CARCINOGENICITY DATA: Limited.

A4; Not classifiable as a human carcinogen.

Group 2B: Possibly carcinogenic to humans

Volume 30: (1983) Miscellaneous Pesticides

Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print)

Volume 112: (2017) Some Organophosphate Insecticides and Herbicides

TR-070: Bioassay of Parathion for Possible Carcinogenicity (CASRN 56-38-2) (1979 )

08/31/78

Equivocal Evidence

No Evidence

It is concluded that under the conditions of this bioassay, parathion was not carcinogenic to B6C3F1 mice. In the male and female Osborne-Mendel rats receiving parathion in their diet, there was a higher incidence of cortical tumors of the adrenal than in pooled or historical controls, suggesting that parathion is carcinogenic to this strain of rat.

3, not classifiable as to its carcinogenicity to humans. (L135)

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.

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

inhalation, skin absorption, ingestion, skin and/or eye contact

Oral(L633) ; inhalation (L633) ; dermal (L633).

Pupillary constriction, muscle cramp, excessive salivation. Sweating. Nausea. Vomiting. Dizziness. Headache. Convulsions. Diarrhoea. Weakness. Laboured breathing. Wheezing. Unconsciousness.

MAY BE ABSORBED! Further see Inhalation.

MAY BE ABSORBED! Redness. Pain. Blurred vision.

Abdominal cramps. Diarrhoea. Vomiting. Further see Inhalation.

irritation eyes, skin, respiratory system; miosis; rhinorrhea (discharge of thin nasal mucus); headache; chest tightness, wheezing, laryngeal spasm, salivation, cyanosis; anorexia, nausea, vomiting, abdominal cramps, diarrhea; sweating; muscle fasciculation, lassitude (weakness, exhaustion), paralysis; dizziness, confusion, ataxia; convulsions, coma; low blood pressure; cardiac irreg

Parathion exposure can result in headaches, convulsions, poor vision, vomiting, abdominal pain, severe diarrhea, unconsciousness, tremor, dyspnea, and finally lung-edema as well as respiratory arrest. (L633)

Endocrine (Glands and Hormones), Immunological (Immune System), Neurological (Nervous System)

Eyes, skin, respiratory system, central nervous system, cardiovascular system, blood cholinesterase

Chemical: PARATHION

Neurotoxin - Predominantly motor

Other Poison - Organophosphate

ACGIH Carcinogen - Not Classifiable.

FAO/WHO ADI: 0.005 mg/kg bw

ATSDR Final

Ethyl Parathion

Children

LD50 DENDROCYGNA BICOLOR (FULVOUS WHISTLING-DUCK) ORAL 0.125-0.250 MG/KG /SAMPLE PURITY, 98.76%/

LD50 MALLARD ORAL 2.13 MG/KG (95% CONFIDENCE LIMIT 1.54-2.96 MG/KG), 3-4 MO OLD MALES /98.76% TECHNICAL GRADE/

LD50 ANAS PLATYRHYNCHOS (MALLARD) ORAL 1.90 MG/KG (95% CONFIDENCE LIMIT 1.37-2.64 MG/KG), 2-3 MO OLD FEMALES /SAMPLE PURITY, 98.76%/

LD50 PHASIANUS COLCHICUS (PHEASANT) ORAL 12.4 MG/KG, 2-3 MO OLD MALES /SAMPLE PURITY, 98.76%

For more Ecotoxicity Values (Complete) data for PARATHION (43 total), please visit the HSDB record page.

3.80e+02

4.90e+03

8.60e+01

2.00e+02

4.30e-01

6.00e-03

Volatile

1.10e+03

1.50e+04

2.60e+02

The substance is very toxic to aquatic organisms. This substance may be hazardous to the environment. Special attention should be given to birds. The substance may cause long-term effects in the aquatic environment. This substance does enter the environment under normal use. Great care, however, should be taken to avoid any additional release, for example through inappropriate disposal.

Parathion's former use as an insecticide and acaricide resulted in its direct release to the environment. If released to air, a vapor pressure of 6.68X10-6 mm Hg at 20 °C indicates parathion will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase parathion will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 4.2 hours. Particulate-phase parathion will be removed from the atmosphere by wet and dry deposition. Parathion absorbs radiation with wavelengths shorter than 320 nm, suggesting a potential for direct photolysis. If released to soil, parathion is expected to have moderate to no mobility based upon Koc values ranging from 314 to 15,860. Volatilization from moist and dry soil surfaces is not expected to be an important fate process based upon its Henry's Law constant of 2.98X10-7 atm-cu m/mole and vapor pressure, respectively. After 8 weeks of incubation in an organic and a mineral soil, <2 and 6%, respectively, of the applied parathion remained. Prior exposure of soils to p-nitrophenol resulted in increased mineralization of parathion to carbon dioxide. p-Nitrophenol, diethylthiophosphoric acid and paraoxon have been identified as metabolites under oxidative conditions; under low oxygen conditions reduction to aminoparathion occurs. The half-life for photodecomposition of parathion on 3 soils ranged from 31 to 70 hr. If released into water, parathion is expected to adsorb to suspended solids and sediment in the water column based upon sediment Koc values ranging from 3,086 to 38,000. Parathion biodegrades in acclimated natural waters within several weeks; it completely degraded to aminoparathion within 2 weeks in acclimated water from Holland Marsh, Ontario. After 30 days incubation in non-sterile coastal river water, only 6 to 21% of parathion remained. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's Henry's Law constant. BCFs ranging from 63 to 462 suggest bioconcentration in aquatic organisms is moderate to high. Reported hydrolysis half-lives at 20 °C at environmentally relevant pHs range from 3 weeks at pH 9 to 43 weeks at pH 5. The half-life for hydrolysis in sterile sea water has been reported to be approximately 1 yr at 4 °C. Divalent cations may catalyze hydrolysis. 20% of parathion was lost by photolysis in 2 hr in Okeefenokee Swamp water. Occupational exposure to parathion may occur through inhalation of spray mists and dermal contact with this insecticide during or after its application. The general population may be exposed to parathion via inhalation of ambient air and ingestion of contaminated food. Parathion has been widely detected in soil and surface water. (SRC)

Parathion is not known to occur as a natural product(1).

/The authors/ called attention to the residue of parathion on the foliage of trees and vines as a source of poisoning. They investigated 11 episodes of group poisoning involving more than 70 persons from pesticide residues on the surfaces of plants. Illness was confirmed by low blood cholinesterase values.

In the US, some or all applications are classified as Restricted Use Pesticide(1). Parathion's former use as an insecticide and acaricide(1) resulted in its direct release to the environment(SRC). Parathion's use in U.S. agriculture in 1966, 1971, 1976, 1982, and 1989 was 8,452,000, 9,481,000, 9,268,000, 6,384,000, and 6,030,000 lbs AI/year, respectively(2). Parathion was released into the Rhine River following a fire at a Sandoz warehouse in Switzerland; the estimated discharge was 50 to 290 kg(3). 21.5% and 5.6% of the acres planted with lettuce and tomatoes, respectively, in California were treated with parathion in 1986; <1.0% of the acres planted with apples in CA in 1986 were treated with parathion(4).

AQUATIC FATE: ... PARATHION ... SHOWN TO BE 2-3 TIMES MORE PERSISTENT THAN METHYL PARATHION IN NATURAL WATER SYSTEMS.

TERRESTRIAL FATE: PERSISTENCE OF PARATHION WAS PARTIALLY DEPENDENT ON SOIL TYPE. IN SOME SOILS DEGRADATION WAS RAPID & PROBABLY THROUGH COMBINATION OF HYDROLYSIS & STRONG MICROBIAL ACTIVITY. IN OTHER SOILS ... LOSS WAS SLOW & ATTRIBUTABLE TO HYDROLYSIS.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 314 to 15,860(2) indicate that parathion is expected to have moderate to no mobility in soil(SRC). Volatilization of parathion from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 2.98X10-7 atm-cu m/mole(4). Parathion is not expected to volatilize from dry soil surfaces based upon a vapor pressure of 6.68X10-6 mm Hg at 20 °C(4). The half-life for photodecomposition of parathion on 3 soils with various water contents ranged from 31 to 70 hr(5). After 8 weeks of incubation in an organic and a mineral soil, <2 and 6%, respectively, of the 1 ppm parathion applied remained; in sterilized controls 80 and 95% remained(6). Prior exposure of soils to p-nitrophenol resulted in increased mineralization of parathion to carbon dioxide(7). Metabolic pathways involve both oxidative and reductive reactions(8). The primary oxidative pathway involves an initial hydrolysis to p-nitrophenol and diethylthiophosphoric acid; a second oxidative pathway involves oxidation to paraoxon(8). Under low oxygen conditions reduction to aminoparathion occurs(8).

AQUATIC FATE: Based on a classification scheme(1), sediment Koc values ranging from 3,086 to 38,000(2) indicate that some adsorption of parathion to suspended solids and sediment in the water column is expected(SRC). Parathion is not expected to volatilize from water surfaces(3) based upon a Henry's Law constant of 2.98X10-7 atm-cu m/mole(4). According to a classification scheme(5), BCFs ranging from 63 to 462(6), suggest bioconcentration in aquatic organisms is moderate to high(SRC). Irradiation of parathion for 10 hr in aerated distilled water resulted in 88% degradation(7). 20% of parathion was lost by photolysis in 2 hr in Okeefenokee Swamp water(8). Reported hydrolysis half-lives at 20 °C at environmentally relevant pHs range from 3 weeks at pH 9(9) to 43 weeks at pH 5(10); the half-life for hydrolysis in sterile sea water has been reported to be approximately 1 yr at 4 °C(11). It is thought that divalent cations catalyze hydrolysis(11). Parathion biodegrades in acclimated natural waters within several weeks(12,13). Parathion, 5 ppm, completely degraded within 2 weeks in acclimated water from Holland Marsh, Ontario, being almost quantitatively converted to aminoparathion; only 10% degradation occurred in 16 weeks when the water was sterilized(12). After 30 days incubation in non-sterile (sterile) coastal river water, only 21, 14, and 6% (64, 57, and 49%) of parathion remained at pH values of 6,7, and 8.16, respectively(14).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), parathion, which has a vapor pressure of 6.68X10-6 mm Hg at 20 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase parathion is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4.2 hours(SRC) from the estimated rate constant(3). Particulate-phase parathion may be removed from the air by wet and dry deposition(SRC). Parathion absorbs radiation with wavelengths shorter than 320 nm(4), suggesting a potential for direct photolysis(SRC).

Parathion biodegrades in acclimated natural waters within several weeks(1,2). 5 ppm of parathion completely degraded within 2 weeks in acclimated water from Holland Marsh, a vegetable growing area in Ontario, being almost quantitatively converted to aminoparathion; only 10% degradation occurred in 16 weeks when the water was sterilized(1). In the waters of the Little Miami River, OH, a small stream which receives domestic and industrial waste as well as farm runoff, 50% of parathion (10 ppb) degraded in 1 week and none could be detected after 4 weeks(2). Surface water of varying salinity (0 to 28 ppt), collected from the Mississippi Sound estuary system degraded parathion with a 45-day half-life at 30 °C which was independent of salinity(3). Both chemical and the biological action of marine plankton were responsible(4). When the water was filtered to remove the plankton, the half-life at 27 °C increased from 41 to 56 days(4). Parathion (1.4 to 28 ppm) degradation in soil with 3 different moisture contents increased with parathion concentration and moisture content(5). The percentage of parathion degraded after 11 days ranged from 96% at high concentration and moisture levels to 20% at low concentrations and moisture levels(5). Further degradation was very slow and the degradation was never complete(5). One reference claims that residues of parathion persisted for >16 yr but the level of application was extremely high(6). After 8 weeks of incubation in an organic and a mineral soil, <2 and 6%, respectively, of the 1 ppm parathion applied remained; in sterilized controls 80 and 95% remained(7). The half-life of parathion (10 ppm) in a sandy loam and organic soil was <1 and 1.5 weeks with only 5% remaining after 3 and 10 weeks, respectively(9). A lag period of approximately 2 weeks occurred when 0.1 and 1 ppm parathion was incubated in Willamette clay loam at moisture levels of 50% field capacity; half-lives were 16 and 26 weeks, respectively(11). Metabolic pathways involve both oxidative and reductive reactions(9). The primary oxidative pathway involves an initial hydrolysis to p-nitrophenol and diethylthiophosphoric acid(9). A second oxidative pathway involves oxidation to paraoxon(9). Under low oxygen conditions reduction to aminoparathion occurs(9). When parathion (500 ppm) is incubated in flooded alluvial soil, 43% remained after 6 days and 0.09% after 12 days(12). The parathion is reduced to aminoparathion under these anaerobic conditions. Amendation of the soil with rice straw increases the rate of degradation(12). In parallel experiments in which parathion was incubated for 30 min in soil suspensions of 5, 30-day flooded (anaerobic) soils and aerobic soils, no degradation occurred in the aerobic soils, while 35 to 68% degradation occurred in the anaerobic soils. The most reduced soils effected the most rapid degradation(13). After repeated application of parathion to flooded soils the degradation pathway shifts from reduction to hydrolysis(14). Parathion is more persistent in flooded saline soils than non-saline soils; degradation was completed in 20 days in a non saline soil and the degradation rate decreased with salinity in 5 soils, ranging from 10 to 50% in 20 days(15). Parathion is degraded in activated sludge treatment plants. With adequate aeration, high levels of parathion wastes were destroyed within 7-10 days in a treatment plant(8). Parathion is destroyed during composting agricultural wastes(10).

Prior exposure of soils to p-nitrophenol resulted in increased mineralization of parathion to carbon dioxide; nearly two-thirds of applied parathion was converted to soil-bound residues and carbon dioxide in soils pre-treated 4 times with p-nitrophenol as compared to 39% in soils with no pretreatment(1). After 30 days incubation in non-sterile coastal river water, only 21, 14, and 6% of parathion remained at pH values of 6,7, and 8.16, respectively; in sterilized coastal river water, 64, 57, and 49% of the initial parathion remained after 30 days incubation at pH values of 6, 7, and 8.16, respectively(2).

The photolysis of parathion was studied in water, aqueous methanol, or aqueous propanol in presence of other compounds, under aerated, or degassed conditions. p-Nitrophenol was the main product of photolysis. Paraoxon was also obtained in some cases. Degradation was higher in water, than in other solvents.

PARATHION UNDERGOES 3 /TYPES/ CHEMICAL CONVERSIONS IN THE ENVIRONMENT. FIRST IS SUBSTITUTION OF OXYGEN FOR SULFUR BOUND TO PHOSPHORUS, YIELDING PARAOXON. FORMATION OF PARAOXON IS ENHANCED IN PRESENCE OF ULTRA-VIOLET LIGHT, & DECOMP ALSO RESULTS IN FOLLOWING PRODUCTS: O,S-DIETHYL O-4-NITROPHENYL PHOSPHOROTHIOATE; O,O-DIETHYL S-4-NITROPHENYL PHOSPHOROTHIOATE; O,O-BIS(4-NITROPHENYL) O-ETHYL PHOSPHOROTHIOATE; O,O-BIS(4-NITROPHENYL) O-ETHYL PHOSPHATE; O,O-DIETHYL O-PHENYL PHOSPHOROTHIOATE & O,O-DIETHYL O-PHENYL PHOSPHATE. THE SECOND CHEMICAL REACTION ... IS HYDROLYSIS AT ESTER LINKAGE, YIELDING DIETHYLPHOSPHOROTHIOIC ACID & PARA-NITROPHENOL. THIS IS PRINCIPAL MECHANISM BY WHICH PARATHION DEGRADES IN THE ENVIRONMENT. ... THIRD CHEMICAL REACTION INVOLVES REDN OF AROMATIC NITRO GROUP TO FORM AMINOPARATHION ...

Reported hydrolysis half-lives at 20 °C at environmentally relevant pHs are: 22 wk(1) and 43 wk(2) at pH 5; 33 wk(2) and 24 wk(3) at pH 6; 24 wk at pH 7(2); 15 wk(1) and 19 wk(3) at pH 7.4; 15 wk at pH 8(2); and 3 wk at pH 9(1). An increase in temperature from 20 to 37.5 °C at pH 7.4 resulted in a decrease in the half-life from 19 wk to 3.8 wk(3). At pH 9 the half-life decreases from 22 days to 5 days when the temperature is increased from 20 to 40 °C(4). The presence of metal ions can have a catalytic effect on hydrolysis as is shown by the decrease in half-life of formulated sprays in the presence of Cu(II)(5) and in other experiments by Cu(II) and Ca(II)(6). However, it is not clear how much of an effect the presence of metal ions will have in natural waters. Experiments which were performed in 4 soils with pH 5.2 to 8.0 gave somewhat erratic results but did not show any pronounced effect of pH on the degradation rate(2). The half-life for chemical hydrolysis in sterile sea water has been reported to be approximately 1 yr at 4 °C(7). pH is not a demonstrable factor in the hydrolysis of parathion in seawater at pHs between 7.8 and 8.8 and it is thought that divalent cations catalyze the hydrolysis(7).

Parathion absorbs light in the environmental spectrum, >290 nm; irradiation for 10 hr in aerated distilled water resulted in 88% degradation(1). Other studies resulted in seemingly contradictory results - slow degradation under photolysis - but at pH 5.5(2). The predicted half life for photolysis in near surface water during midsummer at 40 deg N latitude is 10 days(11). Photosensitizers which may occur in eutropic natural waters may accelerate photolysis. While 20% of parathion in distilled water was lost by photolysis in 18 hr, the same loss occurred in only 2 hr in Okeefenokee Swamp water(5). It has also been shown that the presence of algae can accelerate the photolysis rate by a factor of 27(6,12). The presence of hydrogen peroxide at concentrations that occur naturally in agricultural irrigation water and other surface water has been shown to increase the rate of photodegradation(7). The addition of hydrogen peroxide to distilled water reduced parathion remaining in solution from 65 to 28% when exposed to October sunlight for 245 hr(7). Thin films of parathion such as may be formed on leaves and other surfaces after spraying have a photodegradation half-life of 88 hr(3). Conversion products on leaf surfaces and dry dust particles in field tests are paraoxon and p-nitrophenol(4). Parathion conversion to paraoxon occurs rapidly in air, is promoted by sunlight and takes place largely in the vapor phase(13). The photolysis half-life of parathion as determined in a laboratory photoreactor was 41 min (8,9). This half-life was reduced to 23 min in the presence of >1 ppm ozone (8,9). Field experiments performed by releasing parathion as an emulsifiable concentrate and sampling downwind resulted in a half-life of 5 min at 4 PM (early June), and 131 min after sunset(8,9). The reason for the discrepancy between laboratory and field experiments has not been completely resolved. The presence of soil, dust, or clay minerals in addition to ozone and UV light catalyzes the conversion of parathion to paraoxon(10). While at normal ozone levels (30 ppb) paraoxon production was quite low (approx 2.1 to 4.1% in 8 hr), at ozone levels found under smog conditions (300 ppb), 10 to 65% conversion was found in 8 hr(10). Kaolinite was more effective than montmorillonite in catalyzing photooxidation(10).

For more Environmental Abiotic Degradation (Complete) data for PARATHION (6 total), please visit the HSDB record page.

... ALTHOUGH NO SPECIFIC DATA ARE AVAILABLE ON POSSIBLE BIOACCUMULATION OR BIOMAGNIFICATION OF PARATHION ... PHYS, CHEM, & BIOL PROPERTIES MAKE IT UNLIKELY THAT THESE PHENOMENA WILL OCCUR IN FOOD CHAINS OR FOOD WEBS.

Tadpoles, a species resistant to cholinesterase inhibitors such as organophosphate pesticides, had an average bioconcentration factor of 64(1). BCFs ranging from 63 to 462 were observed in bluegill after 0.5 and 3 days exposure to parathion concentrations of 510 and 640 ug/l, respectively(2). BCFs ranging from 68 to 344 were observed in brook trout after 0.33 and 5.83 days exposure to parathion concentrations of 3,180 and 270 ug/l, respectively(2). In a terrestrial-aquatic ecosystem, there was no evidence for bioaccumulation in any of the organisms, including snails, algae, daphnia, mosquito larvae, and fish, at the end of the 38-day experiment, although the ecosystem organisms contained radiolabeled carbon indicating the presence of metabolism products(3). There is no evidence of bioaccumulated parathion in cattle, sheep, or rabbits(3). The average BCF in killifish after 24 to 72 hours exposure to the individual pesticide was 98; the average BCF was 88 in killifish after 24 to 72 hours exposure to a mixture of pesticides, including parathion(4). According to a classification scheme(5), these BCFs suggest bioconcentration in aquatic organisms is moderate to high. The accumulation of total radioactivity by midge larvae over a 24-hour period was inversely correlated with temperature, respective (14)C-equivalents of parathion, paraoxon, and metabolites were, ng/kg: 48.7, 310.3, and 1201.0 at pH 4 and 10 °C ; 16.7, 8.3, and 1177.0 at pH 4 and 20 °C; 36.3, 40.0, and 884.0 at pH 4 and 30 °C; 67.7, 505.0, and 878.3 at pH 6 and 10 °C; 33.0, 63.3, and 1025.7 at pH 6 and 20 °C; 22.7, 69.7, and 895.0 at pH 6 and 30 °C ; 61.3, 123.3, 1094.7 at pH 8 and 10 °C; 83.3, 89.3, and 126.2 at pH 8 and 20 °C; and 86.0, 60.7, and 767.0 at pH 8 and 30 °C(6).

Parathion had a mobility 0.01 compared to that of water in a French soil(2) and ranked 36 and 40 in a ranking of 41 pesticides by attenuation factor and retardation factor respectively, in 2 sandy soils(5). Some reported Koc values are: 674 (average for 8 Israeli soils) and 1538 (average for 4 Israeli sediments)(1); 10454 for 4 soils(3); 314 to 15860 for unspecified number of soils(4); 2000 average(6); 1310 to 4490 in 6 soils from India(7); 4800(8); 965 to 1700 in 4 soil types with percent organic carbon ranging from 0.41 to 43.7%(9); 1600 to 6200 for 4 Israeli soils(11); 602 to 805 in 5 sterilized Iowa soils(12). The fraction of parathion leached from soil by 10 successive 200 ml applications of water to a soil column was 1.24 and 4.36 for an organic soil and sand, respectively(9). Only a small fraction of parathion adsorbed to a sandy loam, 10%, was found to undergo diffusion (diffusion constant in soil with highest moisture content 0.03 sq cm/day)(10). In soil columns of Nacodoches clay subsoil, parathion leached to 60 inches when 230 inches of rainfall was simulated, while in Houston black clay, 1725 inches of rain were required to produce leaching to 60 inches(13). In field studies, little leaching occurred in 16 yr after 4 annual applications of parathion despite 42 inches of precipitation per year(13). Little parathion was found below 9 inches, 6 yr after 30,000 to 95,000 ppm was applied to the soil(14). In a 15-yr study of residues in a light sand soil, no parathion was found below 8 inches(13). In an 8 mo persistence test under experimental conditions with 20 cm of simulated rain, no parathion was found below 1 inch. In cases where small amounts of parathion penetrated into the soil, it was believed to be the result of the movement of particulate or microparticulate matter containing sorbed parathion(13). In a field study involving the application of parathion to a peach orchard providing watershed for a 2.7 acre pond, no residue was found below 6 inches and there appeared to be little desorption of the insecticide from the bottom sediment of the pond(15). According to a classification scheme(16), these Koc values suggest that parathion is expected to have moderate to no mobility in soil.

In wet soils, parathion sorbed to soil by complexing with water, whereas in dehydrated soil saturated with cations, complexation was direct(1). Koc values of 38,000, 3,086, and 6,404 were determined in batch adsorption experiments using sediments from the Windrush river catchment(2).

The Henry's Law constant for parathion is 2.98X10-7 atm-cu m/mole(1). This Henry's Law constant indicates that parathion is expected to be essentially nonvolatile from water surfaces(2). Parathion's Henry's Law constant(1) indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Parathion is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 6.68X10-6 mm Hg(1). The vapor loss rate of the technical grade chemical from a non-absorbing surface is 0.210 ug/sq cm/hr(3). Vapor losses from soil-incorporated methyl parathion were much lower than from glass surfaces and the same trend would probably apply to parathion(3). Simulations of parathion losses from soil result in only 0.1 to 0.3% losses in 30 days when incorporated into 10 cm of soil(4). Volatilization in a laboratory environmental chamber designed to simulate a soil pit resulted in 0.8% volatilization in 1 day from wet soil and considerably less from dry soil(5). A laboratory experiment determined that the volatilization half-life for parathion from water 4.5 cm deep was 14 and 9.3 days from unstirred and stirred solutions respectively, at 24 °C (equivalent to 311 and 206 days for water 1 m deep)(6). 8% of parathion volatilized in one day in a laboratory experiment designed to simulate an evaporation pond during which time none was lost from hydrolysis(7).

DRINKING WATER: Parathion was not detected in samples of drinking water from 10 to 13 US cities collected between Oct 1975 and Mar 1982 for Infant and Toddler Total Diet samples(1-5). It was not detected in beverages (which included drinking water) in the adult Total Diet Studies from Oct 1965 to Mar 1982(6-9). No parathion was detected in 54 monitored wells in selected California communities(10). The wells selected for monitoring were primarily municipal supply systems near agricultural areas(10). Contaminated drinking water wells in CA contained 4.6 ppb(11). In unspecified drinking water parathion was detected at a level of 30 parts per trillion(12). It was not detected in Ottawa tap water (detection limit <1 parts per trillion)(13).

SURFACE WATER: Parathion was detected in the following samples collected during a USGS survey of western streams in which 20 stations were analyzed for parathion quarterly from Jan to June 1970 and monthly from July 1970 to Sept 1971: Gila River, AZ 40 parts per trillion (2 samples), Sacramento River at Verna CA, 40 parts per trillion and 160 parts per trillion in 2 samples(1). Parathion was not detectable in any water sample in Little Miami River, OH above and below municipal wastewater outfall, July-Sept 1984(2). In a survey of surface waters in Germany 5 to 65 parts per trillion were detected in 4 of 119 samples of unfiltered water from 28 locations and 0.15 to 0.4 parts per trillion in suspended solids in 3 samples from 20 sites(3). It was not detected in any water or suspended particulate matter samples in Lake Superior, and Lake Huron, including Georgian Bay at quantitation limits of 5 parts per trillion and 100 pg, respectively(4). The highest parathion concentration reported in surface water was 0.4 ppb(5). In the Erie River Basin, parathion was not detected in the >100 samples tested(6). Parathion was detected at 0.6% of 174 sampling stations of the nation's rivers(7). Parathion was detected in water samples collected from the Po River and the Adriatic Sea between April and Aug 1988 at concentrations ranging from <1 to 8.9 ng/l; the highest concentration was detected in the Po River near the town of Ferrara, Italy in June(8). Parathion was detected in a water sample collected from the Pinios River, Greece in Feb 1993 at a concentration of 0.15 ug/l(9). Parathion was detected in water from the Rhine River near Cologne at a concentration of 0.08 ug/l(10). 8 of 40 water samples collected from the Valencia Community, Spain, between Feb 1992 and July 1992, contained parathion at concentrations ranging from 0.012 to 0.176 ug/ml(11).

SURFACE WATER: Parathion was detected in ditch water draining cranberry bogs treated with parathion in the Lower Fraser Valley of British Columbia, Canada; concentrations ranged from not detected to 21 ug/l(1). Parathion was detected in farm ditch water collected from the Lower Fraser Valley of British Columbia, Canada, between July and Dec 1991, at mean concentrations of 0.13 and 0.20 ug/kg at Westham Island and Cloverdale, respectively(2).

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P089, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Potential candidate for rotary kiln incineration, with a temperature range of 820 to 1,600 °C and a residence time of seconds. Also, a potential candidate for fluidized bed incineration, with a temperature range of 450 to 980 °C, and a residence time of seconds. Also, a potential candidate for liquid injection incineration with a temperature range of 650 to 1,600 °C, and a residence time of 0.1 to 2 seconds.

The following wastewater treatment technologies have been investigated for parathion: Reverse osmosis.

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas.

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

For more DOT Emergency Guidelines (Complete) data for PARATHION (8 total), please visit the HSDB record page.

UN 2783; Organophosphorus pesticides, solid, toxic

NA 2783; Parathion

IMO 6.1; Organophosphorus pesticides, solid, toxic

49 214 69; Parathion liquid

49 214 71; Parathion mixture, liquid

49 205 35; Parathion and compressed gas mixture

49 214 70; Parathion mixture, dry

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Do not transport with food and feedstuffs. Severe marine pollutant.

Symbol: T+, N; R: 24-26/28-48/25-50/53; S: (1/2)-28-36/37-45-60-61

UN Hazard Class: 6.1; UN Pack Group: I