malathion

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

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

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]

P261, P264, P270, P272, P273, P280, P301+P317, P302+P352, P321, P330, P333+P317, P362+P364, P391, and P501 (click each P-code to see the statement)

H302 (97.4%): Harmful if swallowed [Warning Acute toxicity, oral]

H317 (98.3%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H331 (15.9%): Toxic if inhaled [Danger Acute toxicity, inhalation]

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]

P261, P264, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P316, P321, P330, P333+P317, P362+P364, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 232 reports by companies from 8 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.

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

H350: May cause cancer [Danger Carcinogenicity]

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]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

P203, P260, P261, P264, P264+P265, P270, P272, P273, P280, P302+P352, P305+P351+P338, P308+P316, P318, P319, P321, P333+P317, P337+P317, P362+P364, P391, P405, and P501 (click each P-code to see the statement)

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

P260, P261, P264, P270, P272, P280, P301+P317, P302+P352, P308+P316, P321, P330, P333+P317, P362+P364, P405, and P501 (click each P-code to see the statement)

P203, P261, P264, P270, P272, P273, P280, P301+P317, P302+P352, P318, P321, P330, P333+P317, P362+P364, P391, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Half-upright position. Refer immediately for medical attention.

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

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

Rinse mouth. Refer immediately for medical attention.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, administer a slurry of activated charcoal in water and simultaneously call a hospital or poison control center. IMMEDIATELY transport the victim to a hospital. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

(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 promptly - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly.

Breathing: Respiratory support

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

Fire Extinguishing Agents: Dry chemical, carbon dioxide, water spray, foam (USCG, 1999)

Use foam, powder, carbon dioxide.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

A fire should be extinguished with agents suitable to the surrounding combustibles. ... If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. ... From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. ... The only respirators recommended for firefighting are self-contained breathing apparatuses that have full face-pieces and are operated in a pressure-demand or other positive-pressure mode.

Fire extinguishing media: Water, foam, carbon dioxide, dry chemical.

For more Fire Fighting Procedures (Complete) data for MALATHION (6 total), please visit the HSDB record page.

Containers may explode in fire.

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)

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. See Chemical Dangers. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Soak up with inert absorbent material and dispose of as hazardous waste. Keep in suitable, closed containers for disposal.

Evacuate persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Ventilate the area of spill or leak. Absorb liquids in vermiculite, dry sand, earth, peat, carbon, or a similar material and deposit in sealed containers. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.

Do not contaminate water when disposing of equipment washwater or rinsate. /Malathion 8/

Environmental considerations: Air spill: Apply water spray or mist to knock down vapors. /Organophosphorus pesticides, liquid, NOS; Organophosphorus pesticides, solid, NOS/

For more Cleanup Methods (Complete) data for MALATHION (12 total), please visit the HSDB record page.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

MALATHION MAY BE DISPOSED OF BY ABSORBING IN VERMICULITE, DRY SAND, EARTH, OR A SIMILAR MATERIAL ... & /DISPOSING OF SO AS TO MEET LOCAL, STATE, & FEDERAL REGULATIONS/.

For more Disposal Methods (Complete) data for MALATHION (10 total), please visit the HSDB record page.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid inhalation of vapor or mist.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

For more Preventive Measures (Complete) data for MALATHION (27 total), please visit the HSDB record page.

Neutralizing Agents for Acids and Caustics: Liquid bleach solution for decontamination. (USCG, 1999)

Store only in original packaging. Separated from strong oxidants and food and feedstuffs. Keep in a well-ventilated room. Store in an area without drain or sewer access.

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Recommended storage temperature 2 - 8 °C

Store in a secure poison location. ... Store in tightly closed containers in a cool, well-ventilated, uninhabited area below 25 °C. Store to avoid contact with oxidizers and alkaline pesticides. Store where possible leakage from containers cannot endanger the worker. Maintain regular inspection of containers for any leakage. Sources of ignition, such as smoking and open flames, are prohibited where this chemical is handled, used, or stored.

Store in cool, dry, well-ventilated, secure area out or reach of children and animals. ... Do not contaminate food or feed.

Storage of malathion at 54 °C for 2 weeks resulted in an increase of isomalathion from about 0.05% to 0.2%.

For more Storage Conditions (Complete) data for MALATHION (6 total), please visit the HSDB record page.

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]

15.0 [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)

15 mg/m3

150 mg/m3

500 mg/m3

120 mg/m3

390 mg/m3

77 mg/m3

250 mg/m3

50 mg/m3

140 mg/m3

AEGLs Status: Interim

15 [mg/m3]

120 [mg/m3]

390 [mg/m3]

10 mg/m³

TWA 10 mg/m3 [skin]

15.0 [mg/m3], total dust

15 mg/m³ (total dust)

TWA 15 mg/m3 [skin] See Appendix G

250 mg/m3 (NIOSH, 2024)

250.0 [mg/m3]

Excerpts from Documentation for IDLHs: Human data: Workers exposed to initial concentrations up to 85 mg/m3 for 1 hour (that may have declined rapidly) over 42 consecutive days suffered no adverse effects [Golz 1959]. Workers exposed to concentrations that peaked at 56 mg/m3 and averaged 3.3 mg/m3 for 5 hours had normal cholinesterase levels [Culver et al. 1956]. A lethal oral dose of 246 to 471 mg/kg has been reported [Farago 1967; Jusic and Milic 1978]. [Note: An oral dose of 246 to 471 mg/kg is equivalent to a 70­kg worker being exposed to about 11,500 to 22,100 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

250 mg/cu m

250 mg/m³

See: 121755

1.0 [mg/m3], inhalable fraction and vapor

8 hr Time Weighted Avg (TWA): 1 mg/cu m, skin, Inhalable fraction and vapor

Peak Exposure Recommendation: Transient increases in workers' exposure levels may exceed 3 times the value of the TLV-TWA level for no more than 15 minutes at a time, on no more than 4 occasions spaced 1 hour apart during a workday, and under no circumstances should they exceed 5 times the value of the TLV-TWA level. In addition, the 8-hour TWA is not to be exceeded for an 8-hour work period.

Biological Exposure Index (BEI): Determinant: cholinesterase activity in red blood cells; Sampling Time: discretionary; BEI: 70% of individual's baseline. The determinant is nonspecific, since it is also observed after exposure to other chemicals. /Acetylcholinesterase inhibiting pesticides/

A4; Not classifiable as a human carcinogen.

1 mg/m³ (inhalable fraction and vapor) [2000]

(inhalable fraction): 15 mg/m

Although approval of malathion for the European Union market was revoked in 2008, Member States of the European Union voted in 2010 to allow malathion end-use products to be registered for the control of insect pests in agricultural crops; malathion has been re-authorized at the national level in Austria, the Czech Republic, France, Poland, Romania, and Slovakia, and authorization is in progress in Bulgaria and Italy.

Australia: 10 mg/cu m, skin (1990); Federal Republic of Germany: 15 mg/cu m (total particulate), short-term exposure values in preparation, Pregnancy group C, no reason to fear a risk of damage to the developing embryo or fetus when MAK and BAT values are adhered to (1991); United Kingdom: 10 mg/cu m, skin (1991).

A harmful contamination of the air will not or will only very slowly be reached on evaporation of this substance at 20 °C; on spraying or dispersing, however, much faster.

The substance may cause effects on the central nervous system. Cholinesterase inhibition. This may result in convulsions and respiratory depression. The effects may be delayed. Medical observation is indicated.

Malathion is a yellow to dark-brown liquid with a skunk-like odor. Sinks in water. Freezing point is 37 °F. (USCG, 1999)

Deep-brown to yellow liquid with a garlic-like odor. [insecticide]; [NIOSH]

YELLOW-TO-BROWN LIQUID WITH CHARACTERISTIC ODOUR.

Deep-brown to yellow liquid with a garlic-like odor.

Deep-brown to yellow liquid with a garlic-like odor. [insecticide] [Note: A solid below 37 °F.]

Colorless or slightly yellow

Clear colorless liquid when pure

Deep-brown to yellow liquid ... [Note: A solid below 37 degrees F]

Skunk-like odor

Garlic-like odor

Mercaptan odor

313 to 315 °F at 0.7 mmHg (decomposes) (NTP, 1992)

156-157 °C at 7.00E-01 mm Hg

BP: 156-157 °C at 0.7 mm Hg

140 °F (decomposes)

140 °F (Decomposes)

37.1 °F (NTP, 1992)

greater than 325 °F (NTP, 1992)

Above 325 °F (tag open cup)

163 °C c.c.

>325 °F (open-cup)

(oc) >325 °F

less than 1 mg/mL at 70.7 °F (NTP, 1992)

In water, 143 mg/L at 20 °C

Miscible with many organic solvents including alcohols, esters, ketones, ethers, aromatic and alkylated aromatic hydrocarbons and vegetable oils. Limited solubility in certain paraffin hydrocarbons

Soluble in ethanol, benzene and ethyl ether

1.65e-01 g/L

Solubility in water, mg/l: 143 (very slightly soluble)

1.234 at 77 °F (USCG, 1999) - Denser than water; will sink

1.2076 g/cu cm at 20 °C

Relative density (water = 1): 1.2

1.234 at 77 °F

1.2076 @ 20°C

Relative vapor density (air = 1): 11.4

4e-05 mmHg at 86 °F (NTP, 1992)

0.00004 [mmHg]

3.97X10-5 mm Hg at 30 °C

Vapor pressure at 30 °C: negligible

0.00004 mmHg

log Kow = 2.36

Insoluble in water.

Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters

MALATHION is a yellow to brown liquid that solidifies at 2.9 °C, moderately toxic. Organic phosphate insecticide, acts as an inhibitor of cholinesterase. When heated to decomposition it emits toxic fumes of oxides of sulfur and phosphorus [Lewis, 3rd ed., 1993, p. 789].

Incompatible materials: Strong oxidizing agents. Corrodes metal.

Reacts violently with strong oxidizers, magnesium, alkaline pesticides. Attacks metals including iron, steel, tin plate, lead, copper, and some plastics, coatings, and rubbers.

Strong oxidizers, magnesium, alkaline pesticides [Note: Corrosive to metals].

Strong oxidizers, magnesium, alkaline pesticides [Note: Corrosive to metals.]

CDC-ATSDR Toxicological Profile

IDENTIFICATION AND USE: Malathion is a clear colorless liquid when pure. It has been employed for control of citrus orchard-destructive Mediterranean fruit flies and mosquitoes. Malathion is used for the topical treatment of head lice infestation. The drug also has been used for the topical treatment of pubic lice infestation, body lice infestation, and scabies (mite infestation). HUMAN EXPOSURE AND TOXICITY: Manifestations of acute intoxication may include a mix of muscarinic, nicotinic, and CNS effects. Following ingestion of malathion, symptoms may appear rapidly or may be delayed up to 12 hours. Initial signs and symptoms of malathion poisoning may be largely due to excessive muscarinic effects, which may predominate in milder cases; such effects may include nausea, vomiting, abdominal cramps, diarrhea, urinary and/or fecal incontinence, hyperhidrosis, sialorrhea, miosis (pinpoint pupils), bradycardia, lacrimation, and increased nasal, pharyngeal, and bronchial secretions. Nicotinic effects, including muscle fasciculation, muscle weakness, tachycardia, weakness or paralysis of respiratory muscles, and hypotonia, may occur in moderate and severe intoxications. CNS effects may include anxiety, restlessness, and headache. In more severe cases, tremors, confusion, dizziness, drowsiness, a reduction or loss of deep tendon reflexes, seizures, bradycardia, and coma also have been reported; death may occur. Respiratory failure may result from a combination of muscarinic, nicotinic, and CNS effects. In children, the signs and symptoms of poisoning may be predominantly related to the CNS (e.g., seizures, alterations in mental status including lethargy and coma). Hypotonia, muscle weakness, miosis, and excessive salivation also have occurred in children, while some of the typical cholinergic effects (e.g., bradycardia, muscular fasciculation, excessive lacrimation, sweating, bronchial secretion) may be observed less frequently than in adults. Concentrations of up to 400 ug/mL of 95% malathion failed to increase chromosomal aberrations in human hematopoietic cell cultures; however, others reported a positive result in human lymphocytes with 99% pure malathion. A significant increase in chromosomal aberrations was found in the lymphocytes of 14 people intoxicated with a commercial formulation of malathion, as compared with that in healthy controls. Aberrations observed included chromatid breaks, chromatid isobreaks, chromatid exchanges and unstable chromosomal and structural aberrations. There is limited evidence of malathion carcinogenicity in humans for non-Hodgkin lymphoma and prostate cancer. ANIMAL STUDIES: Undiluted malathion dropped on rabbit's eye caused slight immediate irritation. A daily dose of 46 mg/kg malathion ip for fifteen days affected the activity of the adrenal gland and liver glycogen in rats. Neurotoxicity, reflected by the occurrence of leg weakness in atropinized chickens given single, subcutaneous doses of 100 mg/kg malathion. A bioassay of malathion for possible carcinogenicity was conducted in rats. Groups of 49 or 50 rats of each sex were fed diets containing 2,000 or 4,000 ppm malathion for 103 weeks. All surviving rats were killed at 105 or 106 weeks. Malathion was not carcinogenic in male or female rats. Zebrafish larvae were used in order to determine the effects of malathion, on zebrafish behavior and AChE activity. Embryos and larvae were exposed to malathion during different time points in development and then tested at 5 days post-fertilization for behavioral, neurodevelopmental and AChE abnormalities. Malathion altered behaviors in the larvae such as swim speed and rest. Larvae treated with malathion also had significantly smaller forebrain and hindbrain regions compared to controls by 5 days post-fertilization. Malathion was ineffective in inducing sex linked recessive lethal mutations in Drosophila melanogaster. The clastogenic effect of malathion was studied in mice. At 230 mg/kg, increasing the frequencies of abnormal metaphases and chromosomal aberrations were noted in animals killed 6 or 24 hr after injection. Mice injected with 460 mg/kg, exhibited significant increments of abnormal metaphases, gaps, breaks, and chromatid exchanges in relation to controls. Malathion was tested by the plate incorporation assay with Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98 and TA100 as well as with Escherichia coli strain WP2 uvrA-. No increases in revertants with any strain were reported. ECOTOXICITY STUDIES: Moribund mullet, Mugil cephalus, in an estuary sprayed with malathion (3 oz/acre) during a large scale mosquito control operation had about 98% inhibition of brain acetylcholinesterase. Inhibition of acetylcholinesterase and mortality were noted in pinfish 24, 48, and 72 hours at measured concentrations of 142, 92, and 58 ug/L, respectively. A concentration of 31 ug/L caused 34 percent acetylcholinesterase inhibition in pinfish but no deaths in 72 hours. Growth of oyster, Crassostrea virginica, was reduced 32% by 96 hr exposure to 1 mg/L. Bullfrogs (Rana catesbeiana) were exposed to malathion in water in a 28-day static renewal test. Survival was decreased at the level of 2,500 ug/L and higher. Development of tadpoles was significantly delayed by malathion exposure.

Malathion 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.

Malathion

2 x 10 ^-2 mg/kg-day

Pesticide

steady-state adult population; 6/9/2016

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

Cancer Classification: Suggestive Evidence of Carcinogenicity, but Not Sufficient to Assess Human Carcinogenic Potential

There is limited evidence in humans for the carcinogenicity of malathion. Positive associations have been observed with non-Hodgkin lymphoma and cancer of the prostate. There is sufficient evidence in experimental animals for the carcinogenicity of malathion. Malathion is probably carcinogenic to humans (Group 2A).

A4; Not classifiable as a human carcinogen.

Group 2A: Probably 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-192: Bioassay of Malathion for Possible Carcinogenicity (CASRN 121-75-5) (1979 )

05/01/79

No Evidence

Chemical Not Tested in Species/Sex

It was concluded that under the conditions of this bioassay, malathion was not carcinogenic in male or female rats, but the females may not have received a maximum tolerated dose.

TR-024: Bioassay of Malathion for Possible Carcinogenicity (CASRN 121-75-5) (1978 )

01/18/77

It is concluded that under the conditions of this bioassay, there was no clear evidence of the association of the tumor incidence with the administration of malathion to Osborne-Mendel rats or B6C3F1 mice.

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.

◉ Summary of Use during Lactation

Malathion appears to be poorly absorbed after topical application, so it is not likely to reach the breastmilk in large amounts. Some guidelines consider it a second-choice alternative for the treatment of scabies in nursing mothers.

◉ Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

◉ Effects on Lactation and Breastmilk

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

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

Malathion in an acetone vehicle has been reported to be absorbed through normal human skin only to the extent of 8% of the applied dose. Absorption may be increased when malathion is applied to damaged skin. Malathion is rapidly and effectively absorbed by practically all routes including the gastrointestinal tract, skin, mucous membranes, and lungs. However, it is readily excreted in the urine, and does not accumulate in organs or tissues.

Muscle twitching. Pupillary constriction, muscle cramp, excessive salivation. Sweating. Nausea. Dizziness. Convulsions. Unconsciousness. Laboured breathing.

MAY BE ABSORBED! Further see Inhalation.

Abdominal cramps. Diarrhoea. Vomiting. Further see Inhalation.

irritation eyes, skin; miosis, aching eyes, blurred vision, lacrimation (discharge of tears); salivation; anorexia, nausea, vomiting, abdominal cramps, diarrhea, dizziness, confusion, ataxia; rhinorrhea (discharge of thin nasal mucus), headache; chest tightness, wheezing, laryngeal spasm

Symptoms of low dose exposure include excessive salivation and eye-watering. Acute dose symptoms include 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. Hypertension, hypoglycemia, anxiety, headache, tremor and ataxia may also result.

Neurological (Nervous System), Respiratory (From the Nose to the Lungs)

Eyes, skin, respiratory system, liver, blood cholinesterase, central nervous system, cardiovascular system, gastrointestinal tract

LD50; Species: Anas platyrhynchos (Mallard Duck) female age 3-4 months; oral 1485 mg/kg (95% confidence limit: 1020-2150 mg/kg) (sample purity 95%)

LC50; Species: Anas platyrhynchos (Mallard Duck) age 16 days; oral via capsule ad libitum >5000 ppm for 8 days

LC50; Species: Colinus virginianus (Bobwhite Quail) age 14 days; oral 3497 ppm in 5 day diet (95% confidence limit: 2959-4117 ppm) /Technical 95%/

LC50; Species: Coturnix japonica (Japanese quail) age 2 weeks; oral 2128 ppm in 5 day diet (95% confidence limit: 1780-2546 ppm) /Technical 95%/

For more Ecotoxicity Values (Complete) data for MALATHION (153 total), please visit the HSDB record page.

/AQUATIC SPECIES/ ... For Daphnia magna exposed to malathion, the main effects of temperature regime and malathion were observed on cholinesterase activity. The present study demonstrates how environmentally relevant daily temperature variation influences contaminant effects on aquatic invertebrates.

/AQUATIC SPECIES/ ... To investigate the likely consequences of malathion exposure at low doses in juvenile catfish, Clarias batrachus, ...the expression pattern of genes encoding certain transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes which are known to be involved in gonadal development along with histological changes /were studied/. To compare further, ...certain brain specific genes related to gonadal axis /were analyzed/. Fifty days post hatch catfish fingerlings were exposed continuously to 1 and 10 ug/L of malathion for 21 days. Results from these experiments indicated that transcript levels of various genes were altered by the treatments, which may further affect the gonadal development either directly or indirectly through brain. Histological analysis revealed slow progression of spermatogenesis in testis, while in ovary, the oil droplet oocytes were found to be higher after treatment (10 ug/L). ...Findings revealed that the exposure of malathion, even at low doses, hinder or modulate early gonadal development differentially by targeting gene expression pattern of transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes with an evidence on histological changes. Further, some of the genes showed differential expression at the level of brain in male and female sex after the exposure of malathion.

/AQUATIC SPECIES/ The present study investigated the potential ameliorative effects of propolis against malathion toxicity in the blood and various tissues of carp. The fish were exposed to sublethal concentrations of malathion (0.5 and 1 mg/L) for 10 days, and propolis (10 mg/kg of fish weight) was simultaneously administered. Blood and tissue (liver, kidney, and gill) samples were collected at the end of the experiment and analyzed to determine the hematological profile (red blood cell count, hemoglobin concentration, hematocrit level, and erythrocyte indices: mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration), immune response (white blood cell count, oxidative radical production, nitroblue tetrazolium (NBT) activity, total plasma protein and total immunoglobulin levels, and the phagocytic activity), and oxidant/antioxidant status (malondialdehyde and reduced glutathione levels and superoxide dismutase, catalase, and glutathione peroxidase activities) of the fish. The findings of this study demonstrate that malathion has a negative effect on the hematological parameters, immune response, and antioxidant enzyme activities of the fish. However, the administration of propolis ameliorated the malathion-induced toxic effects.

/AQUATIC SPECIES/ Malathion has been detected in surface waters inhabited by threatened and endangered salmon. In the presence of increasing water temperatures, malathion may increase susceptibility to disease and ultimately threaten salmon survival. This work examines the effect of acute and sublethal exposures to malathion on ocean-type subyearling Chinook salmon held under two temperature regimes. Chinook salmon were exposed to malathion at optimal (11 °C) or elevated (19 and 20 °C) temperatures. The influence of temperature on the acute toxicity of malathion was determined by generating 96-hr lethal concentration (LC) curves. A disease challenge assay was also used to assess the effects of sublethal malathion exposure. The malathion concentration that resulted in 50% mortality (LC50; 274.1 ug/L) of the Chinook salmon at 19 °C was significantly less than the LC50 at 11 °C (364.2 ugL). Mortality increased 11.2% in Chinook salmon exposed to malathion at the elevated temperature and challenged with Aeromonas salmonicida compared to fish held at the optimal temperature and exposed to malathion or the carrier control. No difference in disease challenge mortality was observed among malathion-exposed and unexposed fish at the optimal temperature. ...

For more Ecotoxicity Excerpts (Complete) data for MALATHION (30 total), please visit the HSDB record page.

1.30e+03

1.60e+04

3.90e+02

1.00e+01

1.00e-01

2.00e-02

Volatile

3.80e+03

4.90e+04

1.20e+03

The substance is very toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment. This substance may be hazardous to the environment. Special attention should be given to bees. 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.

Malathion's production may result in its release to the environment through various waste streams; its use as an insecticide and an acaricide will result in its direct release to the environment. If released to air, a vapor pressure of 3.97X10-5 mm Hg at 30 °C indicates malathion will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase malathion 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 5 hours. Particulate-phase malathion will be removed from the atmosphere by wet and dry deposition. Malathion contains chromophores that absorb at wavelengths >290 nm and, therefore, may be susceptible to direct photolysis by sunlight. If released to soil, malathion is expected to have low to no mobility based upon Koc values of 927-17,620. Volatilization from moist soil surfaces is not expected to be an important fate process based upon a Henry's Law constant of 4.89X10-9 atm-cu m/mole. Malathion is not expected to volatilize from dry soil surfaces based upon its vapor pressure. The degradation half-life of malathion in five different soils was 1.33-4.14 days. Malathion was degraded 81-94% in 10 days in various non sterile loam soils. If released into water, malathion is expected to adsorb to suspended solids and sediment based upon the Koc values. The degradation half-life of malathion in different types of water was 1.03-3.93 days. Photodegradation may compete with hydrolysis and biodegradation based on a study finding a photolysis half-life of 533 minutes. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's reported Henry's Law constant. Malathion did not bioconcentrate in topmouth gudgeon or pinfish suggesting bioconcentration in aquatic organisms is low. Hydrolysis is the main route of malathion degradation in water with pH >7.0; at pH <7.0, the rate of hydrolysis is slow relative to the rate of biodegradation. Occupational exposure to malathion may occur through inhalation and dermal contact with this compound at workplaces where malathion is produced or used. Monitoring data indicate that the general population may be exposed to malathion via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with consumer products containing malathion. (SRC)

Malathion is not known to occur as a natural product.

Malathion's production may result in its release to the environment through various waste streams; its use as an insecticide and an acaricide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 927-17,620(2), indicate that malathion is expected to have low to no mobility in soil(SRC). Volatilization of malathion from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 4.89X10-9 atm-cu m/mole(3). Malathion is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.97X10-5 mm Hg at 30 °C(4). The degradation half-life of malathion in five different soils was 1.33-4.14 days(5). Half-lives for malathion for radish and carrot soil for the seasons of winter, summer, and post-monsoon were determined to be 6.4, 2.1, and 5.3 days, and 6.6, 2.6, and 5.6 days, respectively(6). Malathion levels found in Southern California after a single spraying event at soil depths of 1 and 0.1 cm were 1.4 ug/g and 14.1 ug/g, respectively(7). Malathion is rapidly degraded in soils with reported degradation in 10 days in various non sterile loam soils of 81-94%, degradation in the same loam soils that were sterile were 5-19%(8).

TERRESTRIAL FATE: The degradation half-life of malathion was reported for five different soils in China(1).[Table#1931]

AQUATIC FATE: Based on a classification scheme(1), Koc values of 927-17,620(2), indicate that malathion is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 4.89X10-9 atm-cu m/mole(4). Malathion did not bioconcentrate in the freshwater fish topmouth gudgeon (Pseudorasbora parva)(5) or in pinfish (Lagodon sp)(6). Hydrolysis half-life for malathion in seawater/sediment systems at pH 7.3-7.7 is 2.0 days and in freshwater at pH 7.4 and 20 °C is 11 days(7). Products of hydrolysis include malaoxon, malathion alpha and beta monoacid, O,O-dimethylphosphorodithioic acid, diethyl fumarate, diethyl thiomalate, O,O-dimethylphosphorothionic acid(8). Hydrolysis is the main route of malathion degradation in water with pH >7.0; at pH <7.0, the rate of hydrolysis is slow relative to the rate of biodegradation(9). Photodegradation may also compete with hydrolysis based on a study finding the first order photolysis rate of malathion in river water as 0.0013/min, this calculates to a half-life of 533 minutes(10). Malathion sorbed by algae was photodegraded more than 25 times faster than malathion in distilled water(11). The half-life for malathion in Limon River water was reported as 10.87, 10.41, 9.73 and 10.50 days under respective experimental conditions of filtered-dark, filtered-sunlight, non-filtered open to the air and non-filtered closed(12). The degradation half-life of malathion in different types of waters was 1.03-3.93 days(13). Malathion proposed degradation pathway in river water proceeds via hydrolysis to O,O-dimethyldithiophosphoric acid followed by oxidation to O,O-dimethylthiophosporic acid(14).

AQUATIC FATE: The degradation half-life (T1/2) and first-order degradation rate constant (k/day) of malathion were reported for five different waters in China(1).[Table#1932]

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), malathion, which has a vapor pressure of 3.97X10-5 mm Hg at 30 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase malathion 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 5 hours(SRC), calculated from its rate constant of 7.7X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase malathion may be removed from the air by wet or dry deposition(SRC). Malathion absorbs light at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

AEROBIC: Malathion, present at 100 mg/L, reached 22% of its Theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test(1). Malathion is rapidly degraded in soils with reported degradation in 10 days in various non sterile (sterile) loam soils: 92% (8%), 94% (5%), and 81% (19%)(2). Biochemical reactions utilized include desulfuration, oxidation, hydrolysis, transfer of alkyl or aryl groups, alkylation, dealkylation, reduction and conjugation(2). The rate of degradation increased with increasing soil organic matter and was related to soil pH(3). C14-Malathion was biodegraded 50% and 10% after 17 days in clay loam (45.3% sand, 19.7% silt, 35% clay, 5.74% organic matter) and sandy soil (74.74% sand, 24.76% silt, 0.5% clay, 1.9% organic matter), respectively(4). In activated sludge, malathion had a first-order degradation rate of 0.161/hr(8). In raw river water (pH 7.3-8.0), malathion was degraded 90% within 2 weeks, no change was observed in distilled water over 3 weeks suggesting that degradation was biological(5). Degradation of malathion was complete in 3 days in non-sterile estuarine sediments, and 57% in 11 days in sterilized sediment(6). Malathion has a first-order degradation rate of 0.902/day and a half-life of 0.8 days under aerobic conditions, under anaerobic conditions a first-order degradation rate of 0.302/day and a half-life of 2.3 days were reported in sediment from San Diego Creek, CA(7). Products of degradation include alpha and beta monocarboxylic acids (major metabolite in soil), and dicarboxylic acid(9).

The rate constant for the vapor-phase reaction of malathion with photochemically-produced hydroxyl radicals has been estimated as 7.7X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Malathion was hydrolyzed 8.1 and 91% immediately after and 4 weeks after application, respectively, at pH 6.0(2). Malathion hydrolysis half-life in water was shown to be 11 and 1.3 days at 20 and 37.5 °C, respectively, pH 7.4(3). Very little or no hydrolysis of malathion was observed at pHs <7.0(4). Malathion had a half-life of 2.0 days in seawater/sediment system at pH 7.3-7.7 and a half-life of 11 days at pH 7.4 and 20 °C in freshwater(5). Hydroxide-catalyzed hydrolysis is the major pathway for malathion degradation in marine systems(5). Products of hydrolysis and oxidation include O,O-dimethylphosphorodithioic acid and diethyl fumarate in basic solution, and diethyl thiomalate and O,O-dimethylphosphorothionic acid in acidic solution(6). Malathion absorbs light at wavelengths >290nm(7) and therefore may be susceptible to photolysis(SRC). Malathion sorbed by algae was photodegraded more than 25 times faster than malathion in distilled water(8). The half-life for thin film of malathion irradiated at 295 to 305 nm was found to be 51 hours at 0.67 nm thickness(9). The first order photolysis rate of malathion in river water is 0.0013/min, this calculates to a half-life of 533 minutes(10). Malathion had plant surface photodegradation half-life on bean leaf in sunlight field conditions of 2 days and on cotton leaf in sunlit greenhouse conditions of 1.2 to 3.8 days(11).

Malathion did not bioconcentrate in the freshwater fish topmouth gudgeon (Pseudorasbora parva)(1). No detectable concentration of malathion was observed in pinfish (Lagodon sp) after exposure to 20-75 ug/L(2). Malathion undergoes biotransformation in fish with some of the metabolites being malaoxon, malathion monoacid, malathion diacid, O,O-dimethyl phosphorodithioate, O,O-dimethyl phosphorodithiolate, O,O-dimethyl phosphorodithionate and O,O-dimethylphosphate(2). Based on the rapid metabolism, bioconcentration of malathion in aquatic organisms is expected to be low(SRC). The BCF for egg masses of the Triaenodes tardus (caddisfly) was found to be 10(3). Malathion had BCFs of 3.0, 23 and 1.2 in axenically cultured parrot feather (Myriophyllum aquaticum), duckweed (Spirodela oligorrhiza L) and elodea (Elodea canadensis), respectively(4).

The Koc of malathion was determined 26 times in a field study conducted with five applications at a 10 day interval in a lychee orchard in northern Thailand; Koc values were reported as 927-17,620(1). Other reported Koc values of malathion in soil are 1175(2), 1200(3) and 1800(4). According to a classification scheme(5), these Koc values suggest that malathion is expected to have low to no mobility in soil(SRC). An experiment conducted to see how much malathion leaches at depths of 50 cm in soil found that most of the malathion is degraded in the higher layers of soil (within the polar carboxylic acid groups) and only small degradation products, that are usually biodegradable, move to the groundwater(6).

The Henry's Law constant for malathion is reported as 4.89X10-9 atm-cu m/mole(1). This Henry's Law constant indicates that malathion is expected to be essentially nonvolatile from water and moist soil surfaces(2). Malathion is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.97X10-5 mm Hg(3).

GROUND WATER: Malathion was not detected in 18 row crop, 20 orchard and 34 public supply groundwater wells sampled 1993 to 1995 from the Central Columbia Plateau, WA(1). Malathion was not detected in 20 orchard and 34 public supply groundwater wells but was detected in 1 of 18 row crop wells when the same wells were tested again 2002 to 2003, detection limits varied and were not reported as this was a trend study(1). Malathion was detected in about 5% of 139 ground water samples collected in rural areas of Catalonia, Spain, representing 13 hydrogeological units, samples were collected 1997 to 1998(2). Malathion was not detected in groundwater samples from Italy as reported in 47 studies published 1997 to 2013(3).

DRINKING WATER: Malathion was not detected in 54 California drinking water wells near areas where products containing malathion (telone or D-D) had been applied for several years(1). Malathion was not detected (detection limit 0.12 ug/L) in 53 residential drinking water wells in a town in Connecticut(2). Malathion was not detected (detection limit 0.043 ppb) in drinking water of 80 randomly selected residences of Maryland, samples were collected Sept 1995 to Sept 1996(3). Malathion was not detected in Ottawa, Ontario, Canada, with a detection limit of 10-15 pg/L(4); however, it was detected in 4 of 91 ground wells at an average concentration of 0.1 ug/L in Southern Ontario, Canada(5). The Arno River in Italy, which supplies drinking water to the people of Florence, was tested for malathion from 1992 to 1995 and found to have a maximum concentration of 0.17 ug/L with 6 and 8 positive samples in 1993 and 1995, respectively, detection limit 0.01 ug/L(6). Malathion was detected in 58% of filtered drinking water sampled from greater Cairo area, Egypt Dec of 2004 at a median concentration of 0.006 ug/L(7).

SURFACE WATER: In a national surface water monitoring program, conducted 1976-80, malathion was detected in 0.3% of the samples at a maximum concentration of 0.18 ppb(1). In a USA Pesticide Monitoring Network program, conducted 1975-80, of 174 stations 0.6% of the samples tested positive(2-3). Malathion was not detected in 157 river water samples from the Lake Erie watershed sampled 1971-72(4). Malathion was listed as a contaminant in the waters of Lake Erie(5). Malathion was detected in 14% of 214 samples collected in 8 urban streams sampled in the US at a maximum concentration of 0.41 ug/L(6). Surface water samples taken from US streams in the Great Lakes basin tested positive for malathion in 100% of 165 samples taken 1994 to 2000 at 0.001-6.40 ug/L(7). Malathion was detected in 8.5% of 142 samples from four locations in the San Joaquin River basin at a maximum concentration of 0.39 ug/L (detection limit 0.005 ug/L), samples were collected Jan to Dec 1993(8). Malathion was detected in 26 of 98 surface water samples taken from the Yakima River basin, WA at <0.005-0.037 ug/L in samples collected May 1999 to Jan 2000(9). Malathion was detected in 2 of 29 samples collected from Crab Creek at Royal Lake, WA between March 1993 and May 1994 at a maximum concentration of 0.025 ug/L(10). Malathion was detected at <0.40-83 ng/L in surface water samples taken at different elevations in California's Sequoia National Park during the summer of 1996(11). Malathion was detected in 23% of samples taken from the Kisco River (part of New York City water supply system) with a maximum concentration of 0.13 ug/L; samples were collected May 2000 to Feb 2001(12). Surface water monitoring for four sites sampled weekly for 14 weeks (July to Sept 2002) in the San Joaquin Valley, CA had one detection of malathion at 0.111 ug/L(13).

SURFACE WATER: In studies of 11 agricultural watersheds in Ontario, Canada, malathion was not detected in samples collected 1975-76 but was detected in 0.8% of samples collected 1976-77 at not detected to 1.80 parts per trillion with an overall mean of <0.01 parts per trillion(1). Malathion concentrations in the Nile River at Rosetta Region in the summer of 1995 to the summer of 1997 were <0.06-0.071 ug/L(2). Malathion was detected at 8.41-503.58, 16.13-421.58 and 4.59-102 ug/L in 18 water samples collected from each of three stations along the Babolrood River, Iran; samples were collected June 2010 to June 2011(3). In a European estuaries study, malathion was not detected in samples from the Scheldt, Ebro and Rhone rivers, but was detected in the Louros River at 7 ng/L; samples were taken Dec 1994 to June 1996(4). Malathion was detected at less than detection limit to 18.6 ug/L in 66 samples collected from the Llobregat River, Spain at four locations; samples were obtained from three sampling campaigns starting Nov 2009 and completed July 2010(5). In raw bank filtered Rhine River water from West Germany, malathion was occasionally detected, not quantified(6). A maximum concentration of 16,000 ng/L of malathion was reported in a review of 47 studies published 1997 to 2003 analyzing Italian surface water samples(7). Malathion was detected in 2 of 96 river water samples collected May 1996 to April 1997 at eight sampling sites in Imathia area of Greece at 0.001 and 0.018 ug/L(8). Malathion was found at 2 of 4 sites sampled from Apr-Aug 1996 from the Shinana River in Japan at 23-28 ng/L(9). River water sample concentrations of malathion were reported as 8.31-43.53 ng/L from the Wuchuan river in China(10). In a comprehensive Chinese surface water survey conducted 2003 to 2004, 217 reservoirs and 406 lakes and rivers were sampled; malathion was detected in 43.5% at <0.8-1290 ng/L(11).

For more Environmental Water Concentrations (Complete) data for MALATHION (6 total), please visit the HSDB record page.

Malathion was detected in agricultural irrigation run-off, agricultural storm run-off and residential storm run-off at concentrations of <10-110, <10-100 and 17-120 ng/L, respectively, samples were collected from the Calleguas Creek watershed southern California Aug 1999 to April 2000(1). Malathion was detected in samples from nine of 13 roof runoff locations in Gdansk, Poland at 0.08-0.52 ng/L; sample dates were March to May 2000(2).

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

MALATHION MAY BE DISPOSED OF BY ABSORBING IN VERMICULITE, DRY SAND, EARTH, OR A SIMILAR MATERIAL ... & /DISPOSING OF SO AS TO MEET LOCAL, STATE, & FEDERAL REGULATIONS/.

For more Disposal Methods (Complete) data for MALATHION (10 total), please visit the HSDB record page.

/GUIDE 131 FLAMMABLE LIQUIDS - TOXIC/ Fire or Explosion: HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion and poison hazard indoors, outdoors or in sewers. Those substances designated with a (P) may polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water. /Organophosphorus pesticide, liquid, poisonous, flammable; Organophosphorus pesticide, liquid, toxic, flammable; Organophosphorus pesticide, liquid, flammable, poisonous; Organophosphorus pesticide, liquid, flammable, toxic/

/GUIDE 131 FLAMMABLE LIQUIDS - TOXIC/ Health: TOXIC; may be fatal if inhaled, ingested or absorbed through skin. Inhalation or contact with some of these materials will irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution. /Organophosphorus pesticide, liquid, poisonous, flammable; Organophosphorus pesticide, liquid, toxic, flammable; Organophosphorus pesticide, liquid, flammable, poisonous; Organophosphorus pesticide, liquid, flammable, toxic/

/GUIDE 131 FLAMMABLE LIQUIDS - TOXIC/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate closed spaces before entering. /Organophosphorus pesticide, liquid, poisonous, flammable; Organophosphorus pesticide, liquid, toxic, flammable; Organophosphorus pesticide, liquid, flammable, poisonous; Organophosphorus pesticide, liquid, flammable, toxic/

/GUIDE 131 FLAMMABLE LIQUIDS - TOXIC/ 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. /Organophosphorus pesticide, liquid, poisonous, flammable; Organophosphorus pesticide, liquid, toxic, flammable; Organophosphorus pesticide, liquid, flammable, poisonous; Organophosphorus pesticide, liquid, flammable, toxic/

For more DOT Emergency Guidelines (Complete) data for MALATHION (16 total), please visit the HSDB record page.

UN 2783; Organophosphorus pesticides, solid, toxic

UN 2784; Organophosphorus pesticides, liquid, flammable, toxic, flash point less than 23 °C

UN 3017; Organophosphorus pesticides, liquid, toxic, flammable, flash point not less than 23 °C

UN 3018; Organophosphorus pesticides, liquid, toxic

For more Shipping Name/ Number DOT/UN/NA/IMO (Complete) data for MALATHION (6 total), please visit the HSDB record page.

49 411 56; Malathion

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. Organophosphorus pesticide, liquid, toxic; Organophosphorus pesticide, liquid, toxic, flammable, flash point 23 °C or more; Organophosphorus pesticide, solid, toxic; and Organophosphorus pesticide, liquid, flammable, toxic, flash point less than 23 °C are included on the dangerous goods list. /Organophosphorus pesticide, liquid, toxic; Organophosphorus pesticide, liquid, toxic, flammable, flash point 23 °C or more; Organophosphorus pesticide, solid, toxic; Organophosphorus pesticide, liquid, flammable, toxic, flash point less than 23 °C/

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. Organophosphorus pesticide, liquid, toxic; Organophosphorus pesticide, liquid, toxic, flammable, flash point not less than 23 °C; Organophosphorus pesticide, solid, toxic; and Organophosphorus pesticide, liquid, flammable, toxic, flash point less than 23 °C are is included on the dangerous goods list. /Organophosphorus pesticide, liquid, toxic; Organophosphorus pesticide, liquid, toxic, flammable, flash point not less than 23 °C; Organophosphorus pesticide, solid, toxic; Organophosphorus pesticide, liquid, flammable, toxic, flash point less than 23 °C/

Do not transport with food and feedstuffs. Marine pollutant.

UN Hazard Class: 9; UN Pack Group: III