Methyl iodide

H301: Toxic if swallowed [Danger Acute toxicity, oral]

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H331: Toxic if inhaled [Danger Acute toxicity, inhalation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H351: Suspected of causing cancer [Warning Carcinogenicity]

P203, P261, P264, P270, P271, P280, P301+P316, P302+P352, P304+P340, P316, P317, P318, P319, P321, P330, P332+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for 0.4% (1 of 264) of reports.

H226 (42.8%): Flammable liquid and vapor [Warning Flammable liquids]

H301+H331 (54.2%): Toxic if swallowed or if inhaled [Danger Acute toxicity, oral; acute toxicity, inhalation]

H301 (99.6%): Toxic if swallowed [Danger Acute toxicity, oral]

H312 (99.6%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H315 (99.6%): Causes skin irritation [Warning Skin corrosion/irritation]

H317 (14.8%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H319 (39.8%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H331 (99.6%): Toxic if inhaled [Danger Acute toxicity, inhalation]

H334 (14.8%): May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]

H335 (99.6%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H351 (96.2%): Suspected of causing cancer [Warning Carcinogenicity]

H400 (42.8%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H411 (42.8%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P272, P273, P280, P284, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P316, P317, P318, P319, P321, P330, P332+P317, P333+P317, P337+P317, P342+P316, P362+P364, P370+P378, P391, P403, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 264 reports by companies from 19 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 1 of 264 reports by companies.

There are 18 notifications provided by 263 of 264 reports by companies with hazard statement code(s).

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.

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

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

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

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]

P260, P261, P264, P264+P265, P270, P271, P280, P284, P301+P316, P302+P352, P304+P340, P305+P351+P338, P308+P316, P316, P319, P320, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

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

P203, P260, P264, P264+P265, P270, P271, P280, P284, P301+P316, P302+P352, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P319, P320, P321, P330, P332+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

P260, P261, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P304+P340, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

P203, P261, P264, P264+P265, P270, P271, P280, P301+P316, P302+P352, P304+P340, P305+P354+P338, P316, P317, P318, P319, P321, P330, P332+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. Refer immediately 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.

Rinse mouth. Do NOT induce vomiting. Give a slurry of activated charcoal in water to drink. 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. Corrosive chemicals will destroy the membranes of the mouth, throat, and esophagus and volatile chemicals have a high risk of being aspirated into the victim's lungs during vomiting. Thus, the risk of increasing the medical problems by inducing vomiting of a volatile corrosive chemical is very high. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY 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.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(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 flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. If irritation persists after washing, get medical attention.

Breathing: Respiratory support

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

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Water spray, fog or regular foam. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal. Avoid aiming straight or solid streams directly onto the product.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2024)

In case of fire in the surroundings, use appropriate extinguishing media. In case of fire: keep drums, etc., cool by spraying with water.

Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive-pressure mode.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself dose not burn or burns with difficulty.) Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Keep run-off water out of sewers and water sources.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Do not touch damaged containers or spilled material unless wearing appropriate protective clothing.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

· Cover with plastic sheet to prevent spreading.

· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.

· DO NOT GET WATER INSIDE CONTAINERS.

· For solids, prevent dust cloud and avoid inhalation of dust.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-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: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 2644 datasheet.

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)

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.

· For highlighted materials: see Table 1 - Initial Isolation and Protective Action Distances.

· For non-highlighted materials: increase the immediate precautionary measure distance, in the downwind direction, as necessary.

· 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.

Small spill:

- ISOLATE in all directions: 30 m (100 ft)

Large spill:

- ISOLATE in all directions: 100 m (300 ft)

- PROTECT people from downwind during DAY time: 0.1 km (0.1 mi)

- PROTECT people from downwind during NIGHT time: 0.2 km (0.1 mi)

- PROTECT people from downwind during DAY time: 0.3 km (0.2 mi)

- PROTECT people from downwind during NIGHT time: 0.7 km (0.4 mi)

Evacuate danger area! Consult an expert! Personal protection: self-contained breathing apparatus. Collect leaking and spilled liquid in sealable containers as far as possible. 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 SIMILAR MATERIAL.

/In laboratory/ absorb the spills with paper towels, or like materials. Place in hood to evaporate. Dispose by burning the towel.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U138, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for liquid injection incineration at a temperature range of 650 to 1,600 °C and a residence time of 0.1 to 2 seconds. A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Proper ventilation and protective devices /should be used/. Periodic determination of gas concentration in work place /should be made/.

Good industrial hygiene practices recommend that engineering controls be used to reduce environmental concentrations to the permissible exposure level. However, there are some exceptions where respirators may be used to control exposure. Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented. Respirators may also be used for operations which require entry into tanks or closed vessels, and in emergency situations. If the use of respirators is necessary, the only respirators permitted are those that have been approved by the Mine Safety and Health Administration (formerly Mining Enforcement and Safety Administration) or by the National Institute for Occupational Safety and Health. In addition to respirator selection, a complete respiratory protection program should be instituted which includes regular training, maintenance, inspection, cleaning, and evaluation.

The following list includes some common operations in which exposure to methyl iodide may occur and control methods which may be effective in each case: Operation (1) Use as a methylating agent in organic synthesis; use as a laboratory reagent; use in academic laboratory courses in organic chemistry. Control (1) Process enclosure; local exhaust ventilation; general dilution ventilation; personal protective equipment. Operation (2) Use as an insecticidal fumigant on scale insects and beetles. Control (2) Process enclosure; general dilution ventilation; personal protective equipment. Operation (3) Use in analytical chemistry laboratories (test for pyridine, evaluating type of sulfur linkage in vulcanized rubber). Control (3) Local exhaust ventilation; general dilution ventilation; personal protective equipment.

For more Preventive Measures (Complete) data for METHYL IODIDE (13 total), please visit the HSDB record page.

Excerpt from ERG Guide 151 [Substances - Toxic (Non-Combustible)]:

Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. For solids, prevent dust cloud and avoid inhalation of dust. (ERG, 2024)

Provision to contain effluent from fire extinguishing. Separated from strong oxidants and food and feedstuffs. Well closed. Ventilation along the floor. Store in an area without drain or sewer access.

Keep containers closed and store in a dark place.

... MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMPOSE INTO TOXIC COMPONENTS DUE TO CONTACT WITH HEAT, MOISTURE, ACID, OR ACID FUMES, SHOULD BE STORED IN COOL, WELL-VENTILATED PLACE, OUT OF DIRECT RAYS OF SUN, AWAY FROM AREAS OF HIGH FIRE HAZARD & SHOULD BE PERIODICALLY INSPECTED & MONITORED.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].

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: ppm)

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

AEGL 3: Life-threatening health effects or death (Unit: ppm)

AEGLs Status: Proposed

25 [ppm]

50 [ppm]

125 [ppm]

2 ppm (10 mg/m³)

Ca TWA 2 ppm (10 mg/m3) [skin] See Appendix A

5.0 [ppm]

5 ppm (28 mg/m³)

TWA 5 ppm (28 mg/m3) [skin]

100 ppm ; A potential occupational carcinogen. (NIOSH, 2024)

100.0 [ppm]

Excerpts from Documentation for IDLHs: Basis for original (SCP) IDLH: The chosen IDLH is based on the mouse 57­minute LC50 of 860 ppm [Buckell 1950 cited by Patty 1963]. . . . Other animal data: In a subchronic study, no rats died following exposures to 150 ppm for 6 hours/day for 3 days [Monsanto 1986]. \\ Human data: None relevant for use in determining the revised IDLH.

NIOSH considers methyl iodide to be a potential occupational carcinogen.

Ca [100 ppm]

See: 74884

2.0 [ppm]

8 hr Time Weighted Avg (TWA): 2 ppm, skin

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.

2 ppm as TWA; (skin).

2 ppm [1978]

skin absorption (H); carcinogen category: 2

Small Fire

· Dry chemical, CO2 or water spray.

Large Fire

· Water spray, fog or regular foam.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Dike runoff from fire control for later disposal.

· Avoid aiming straight or solid streams directly onto the product.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Do not get water inside containers.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

Methyl iodide appears as a colorless liquid that turns brown on exposure to light. Denser than water. Contact may irritate skin, eyes and mucous membranes. Very toxic by ingestion, inhalation and skin absorption.

CBI; Gas Vapor; Liquid

Colorless liquid with a pungent, ether-like odor. [Note: Turns yellow, red, or brown on exposure to light & moisture.] [NIOSH]

COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. TURNS BROWN ON EXPOSURE TO LIGHT AND MOISTURE.

Colorless liquid with a pungent, ether-like odor.

Colorless liquid with a pungent, ether-like odor. [Note: Turns yellow, red, or brown on exposure to light & moisture.]

Colorless, transparent liquid (turns brown on exposure to light)

Pungent, ether-like odor.

108.3 °F at 760 mmHg (NTP, 1992)

42.43 °C @760 [mm Hg]

-87.6 °F (NTP, 1992)

-66.5 °C

-66.4 °C

10 to 50 mg/mL at 64 °F (NTP, 1992)

Miscible with alcohol, ether.

Sol in acetone

SOL IN CARBON TETRACHLORIDE

1.39X10+4 mg/l at 20 °C in water

Solubility in water, g/100ml at 20 °C: 1.4

2.279 at 68 °F (USCG, 1999) - Denser than water; will sink

2.28 @ 20 °C/4 °C

DENSITY OF SATURATED AIR: 3.04 (AIR= 1)

Relative density (water = 1): 2.3

2.2789 @ 20°C

4.9 (AIR= 1)

Relative vapor density (air = 1): 4.9

661.76 mmHg (USCG, 1999)

405.0 [mmHg]

4.05X10+2 mm Hg @ 25 °C

Vapor pressure, kPa at 20 °C: 50

400 mmHg

750 [mm Hg] @42.1 °C

log Kow= 1.51

Henry's constant of 0.00526 atm-cu m/mole at 25 °C

COLORLESS LIQUID THAT TURNS YELLOW, RED OR BROWN WHEN EXPOSED TO LIGHT & MOISTURE.

IODIDE & HYDROGEN IODIDE MAY BE RELEASED WHEN METHYL IODIDE UNDERGOES THERMAL DECOMPOSITION (270 °C).

0.606 cP at 0 °C, 0.424 cP at 40 °C.

0.18 mm²/s at 40 °C

194.7 kg cal/g mole

27.97 kJ/mol @ 25 °C

Soluble in water. Sinks and slowly decomposes in water forming poisonous vapor cloud of HI.

Halogenated Organic Compounds

Halogenated aliphatic compounds, such as METHYL IODIDE, are moderately or very reactive. Halogenated organics generally become less reactive as more of their hydrogen atoms are replaced with halogen atoms. Low molecular weight haloalkanes are highly flammable and can react with some metals to form dangerous products. Materials in this group are incompatible with strong oxidizing and reducing agents. Also, they are incompatible with many amines, alkylphosphines, nitrides, azo/diazo compounds, alkali metals (sodium), and epoxides.

Strong oxidizers [Note: Decomposes at 518 degrees F].

Attempts to react silver chlorite with methyl or ethyl iodides caused explosions, immediately in the absence of solvents, or delayed in the presence of solvents.

... Turns brown on exposure to light.

Violent reaction with oxygen (at 300 °C); sodium.

Explosive reaction with trialkylphosphines; silver chlorite.

Strong oxidizers [Note: Decomposes at 518 °F.]

Methyl iodide

Volatile Organic Compound (VOC) (Pesticide/Volatile Organic Compound (VOC))

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: Not Likely to be Carcinogenic to Humans at Doses that Do Not Alter Rat Thyroid Hormone Homeostasis

Evaluation: No epidemiological data relevant to the carcinogenicity of methyl iodide were available. There is limited evidence in experimental animals for the carcinogenicity of methyl iodide. Overall evaluation: Methyl iodide is not classifiable as to its carcinogenicity to humans (Group 3).

Methyl Iodide: delisted as reasonably anticipated to be a human carcinogen.

Group 3: Not classifiable as to its carcinogenicity to humans

Volume 41: (1986) Some Halogenated Hydrocarbons and Pesticide Exposures

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 71: (1999) Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (Part 1, Part 2, Part 3)

The substance can be absorbed into the body by inhalation of its vapour and by ingestion.

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

Cough. Sore throat. Nausea. Vomiting. Diarrhoea. Headache. Dizziness. Drowsiness. Weakness. Convulsions. Confusion. Death Symptoms may be delayed.

Redness. Pain.

See Inhalation.

irritation eyes, skin, respiratory system; nausea, vomiting; dizziness, ataxia; slurred speech, drowsiness; dermatitis; [potential occupational carcinogen]

Eyes, skin, respiratory system, central nervous system

[in animals: lung, kidney & forestomach tumors]

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Dermatotoxin - Skin burns.

Lacrimator (Lachrymator) - A substance that irritates the eyes and induces the flow of tears.

Toxic Pneumonitis - Inflammation of the lungs induced by inhalation of metal fumes or toxic gases and vapors.

Iodomethane

PDF Document

Inadequate information to assess carcinogenic potential

LC50 (rat) = 1,300 mg/m3/4H

LD50 Mouse sc 0.78 mmoles/kg

LCLO Mouse inhalation 78,693 ppm/10 min.

LCLO Mouse inhalation 18,109 ppm/30 min

LD50 RAT ORAL 76 MG/KG.

LC50 Mouse inhalation 5 mg/l/57 min

For more Non-Human Toxicity Values (Complete) data for METHYL IODIDE (10 total), please visit the HSDB record page.

... SYNERGIZES TOXICITY OF FENITROTHION ELEVEN FOLD & DICHLOROVOS TWO FOLD /IN MOUSE LIVER/.

S-Methyl-N-acetylpenicillamine, S-methylthiol, and S-methylcysteine, as well as iodomethane decreased biliary excretion of methylmercury markedly. Excretion of sulfhydryl in bile was not influenced by S-methylcysteine, S-methylthiol, S-methyl-N-acetylpenicillamine or a low dose of iodomethane (0.5 mmol/kg). This indicated that coupling of methylmercury to glutathione in the liver before biliary excretion was glutathione S-transferase-dependent reaction and the methylthiols tested, or metabolites of these compounds were likely to be inhibitors of S-transferase. The effect of S-methylcysteine and low doses of iodomethane (1 mmol/kg) seem to deplete the liver of reduced glutathione through S-methylation as illustrated by decreased biliary excretion of sulfhydryl.

Flush eyes thoroughly with water and wash contaminated areas of body with soap and water. Treat skin burns as usual.

Physical examination of workers for placement in operations involving possible exposure to these alkylating agents should include consideration of increased personal risk due to cigarette smoking, pregnancy, or treatment with steroids or cytotoxic agents. /Alkylating agents/

IN HUMANS EXPOSED TO METHYL IODIDE, SERUM LIPID CONTENT, ESP THE TRIGLYCERIDE CONTENT WAS SHARPLY INCR, WITH NO APPARENT NERVOUS DISORDER. THUS, BLOOD EXAM, ESP SERUM LIPID, & FUNCTIONAL EXAM OF LIVER & KIDNEY, MAY BE USED FOR EARLY DETECTION OF METHYL IODIDE POISONING.

Initial Medical Examination: A complete history and physical examination: The purpose is to detect pre-existing conditions that might place the exposed employee at increased risk, and to establish a baseline for future health monitoring. Examination of the central nervous system should be stressed. The skin should be examined for evidence of chronic disorders. Periodic Medical Examination: The aforementioned medical examinations should be repeated on an annual basis.

MAY PRODUCE SEVERE ... /SRP: CNS DEPRESSION/; LUNG IRRITATION FROM ACUTE EXPOSURE. PROLONGED CONTACT WITH SKIN CAN CAUSE VESICANT BURNS.

The substance is very toxic to aquatic organisms. 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.

Methyl iodide is produced by marine macroalgae and the ocean is thought to be a major source of methyl iodide. Anthropogenic sources of methyl iodide resulting from its use as a methylating agent are minor compared with biogenic ones. If released to air, a vapor pressure of 405 mm Hg at 25 °C indicates methyl iodide will exist solely as a vapor in the ambient atmosphere. Methyl iodide will degrade in the atmosphere primarily as a result of photolysis. Its photolytic half-life is 2.8 to 5.5 days. By comparison, its half-life as a result of reaction with photochemically-produced hydroxyl radicals is about is about 220 days. If released to soil, methyl iodide is expected to have very high mobility based upon an estimated Koc of 14. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 0.00526 atm-cu m/mole. Methyl iodide should volatilize from dry soil surfaces based upon its vapor pressure. Ninety-four percent of methyl iodide applied 30 cm below the surface of a soil column was lost through volatilization. Abiotic degradation will occur as a result of hydrolysis and reaction with nucleophilic ions such as chloride ions. The half-life of methyl iodide in soils that were rich in organic matter was 9-13 days, while in a sandy loam soil it was 42-63 days. If released into water, methyl iodide is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 1.3 hours and 4.8 days, respectively. Methyl iodide hydrolyzes slowly in water with a half-life of 110-251 days at 20-25 °C in fresh water. In seawater, it reacts with chloride ions and has a half-life of 20 and 58 days at 19.2 and 10.8 °C, respectively. An estimated BCF of 2.9 suggests that the potential for bioconcentration in aquatic organisms is low. Monitoring data indicate that the general population may be exposed to methyl iodide from the ambient air and from ingesting seafood from the ocean. (SRC)

Methyl iodide is formed in the sea as a natural product of marine algae; its estimated annual world production is 4X10+10 kg(1). Methyl iodide production rates of varieties of brown (both kelps and nonkelps), red and green marine microalgae have been measured in the laboratory and estimates of oceanic production of methyl iodide made from these production rates(3). As with previous extrapolations, methyl iodide production rates fail to account for estimated oceanic strengths of the chemical. It is suggested that indirect production of methyl iodide via microbial decay of seaweed iodocarbons may fill this gap(3). However, another investigator pointed out that this additional source is much too small(4). Another explanation is that the results of halocarbon production by algae in the laboratory cannot be extended to natural mixed populations. In addition to oceanic emissions, biomass burning has been identified as a minor secondary source of methyl iodide(2).

Methyl iodide's production and use as a methylating agent and in organic synthesis(1) may result in its release to the environment through various waste streams. Methyl iodide can be formed in the environment of nuclear reactors and vented in exhaust gases(1). Anthropogenic sources have not been identified as major contributors of methyl iodide emissions(2). However, methyl iodide has been suggested as a replacement for methyl bromide as a soil fumigant(3).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 14(SRC), determined from a structure estimation method(2), indicates that methyl iodide should have very high mobility in soil(SRC). Volatilization of methyl iodide from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.00526 atm-cu m/mole at 25 °C(3). The potential for volatilization of methyl iodide from dry soil surfaces may exist based upon a vapor pressure of 405 mm Hg(4). Cumulative volatilization losses of methyl iodide, applied at 30 cm, from 60-cm soil columns packed with a sandy loam soil ranged from 94% when the soil was untarped to 75% with a high-barrier tarp(5). Volatilization losses were significantly lower, 38% and 53%, from soils high in organic matter and capable of rapidly degrading the chemical. Ten days after methyl iodide was applied to field plots (30 cm depth) covered with a polyethylene film, methyl iodide was detected at most depths(5). It was concluded that should the water table be shallow and the degradation rate in soil low, methyl iodide may leach into ground water(5). Methyl iodide abiotically degrades in soil by hydrolysis and reaction with chloride ions, HS- and other nucleophiles(6). The half-life of methyl iodide in soils that were rich in organic matter was 9-13 days, while in a sandy loam soil it was 42-63 days. The organic-rich soils were thought to contain more nucleophiles with which methyl iodide could react(6).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 14(SRC), determined from an estimation method(2), indicates that methyl iodide is not expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 0.00526 atm-cu m/mole at 25 °C(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 1.3 hours and 4.8 days, respectively(SRC). Methyl iodide hydrolyses slowly in water with a half-life of 110-251 days at 20-25 °C(8,9). It reacts with chloride ions in seawater in which its half-life is 20 and 58 days at 19.2 and 10.8 °C, respectively(8). According to a classification scheme(5), an estimated BCF of 2.9(SRC), from its log Kow of 1.51(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), methyl iodide, which has a vapor pressure of 405 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase methyl iodide 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 220 days(SRC), from its rate constant of 7.20X10-14 cu cm/molecule-sec at 25 °C(3). However the major loss process for methyl iodide in the atmosphere is direct photolysis. The half-life of this reaction is 2.8-5.5 days(3,4). Physical removal of methyl iodide from air may occur via wet deposition since methyl iodide is relatively soluble in water(SRC).

Methyl iodide hydrolyses slowly in water yielding methanol(2). The half-life under neutral conditions is 110-251 days at 20-25 °C(1,2), increasing to 4 yr and 23 yr at 10 and 0 °C respectively(1). More recent measurements yielded a unimolecular hydrolysis rate constant of 7.1X10-8 1/sec at 25 °C(6). This is equivalent to a half-life of 110 days(SRC). A base-catalyzed reaction is only important at higher pH's than are observed in the environment(2). However, methyl iodide is unstable in seawater, reacting primarily with the chloride ion to form methyl chloride(1). The half-life in seawater of 19.8 parts/thousand chlorinity is 20 and 58 days at 19.2 and 10.8 °C, respectively(1). More recent studies of the reaction of chloride with methyl iodide reports rate constants for both seawater (33.3 parts/thousand chlorinity) and 0.5 M NaCl in distilled water of 1.0X10-6 L/mol-sec(7). The rate in NaCl corresponds to a half-life of 16 days. Methyl iodide absorbs UV radiation up to approximately 340 nm and photolyses(3). Photolysis occurs in both the gas phase and in solution. In water photohydrolysis occurs forming methanol and iodide ions; in air, iodine is formed(8). When irradiated in pure air (relative humidity 50%), methyl iodide's half-life was 7 hr(4); with added NO2 its half-life was a little over 3 hr(5). The dissipation half-life of methyl iodide from open surface water (30 cm-deep tank) with sunlight irradiation was 26 hours compared with 29 hours indoors. At the end of 6 days, 3.1% of the methyl iodide was recovered as I-; no iodine was detected(8). It was concluded that photodegradation was a minor loss mechanism compared with volatilization.

The rate constant for the vapor-phase reaction of methyl iodide with photochemically-produced hydroxyl radicals is 7.20X10-14 cu cm/molecule-sec at 25 °C(1,2). This corresponds to an atmospheric half-life of about 220 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The major reaction pathway should give rise to CH2I radicals and water(2). A pathway leading to the formation of CH3 radicals and HOI is expected to occur, but to a lesser extent(2). The reaction of methyl iodide with hydroxyl radicals is low compared with the photolysis of methyl iodide, whose half-life of 2.8-5.5 days(2,3). Therefore reaction with hydroxyl radicals is a minor tropospheric process compared with photolysis. The rate constant for the vapor-phase reaction of methyl iodide with nitrate radicals is 1.92X10-17 cu cm/molecule-sec at room temperature(4). This corresponds to an atmospheric half-life of about 4.8 yrs(SRC) at an atmospheric concentration of 2.4X10+8 nitrate radicals per cu cm(5).

Based upon an experimentally determined rate constant of 7.6X10-4/hr, the half-life for the reaction with hydrated electrons (produced by photochemical reaction with dissolved organic matter in water) is about 38 days(2). The hydrolysis rate of methyl iodide in water can be increased by the presence of sulfur nucleophiles(3); the increase is dependent on the nucleophile concn(3). Reaction with HS- has been suggested as an important removal pathway of methyl iodide from a salt marsh(5). The reaction of methyl iodide with dissolved or metal-bound sulfide represents a potential source of environmental dimethyl sulfide(4). Photolysis studies showed that direct photolysis is not as fast in seawater as the SN2 reaction with chloride ion(1); at 29 °C, the half-life in dark seawater control tubes was 7.8 days while in tubes exposed to Miami sunlight, the half-life was 6.2 days(1); the SN reaction half-life with chloride ion varies dramatically with ocean latitude and depth with half-lives ranging from 6 days in the warmest water to thousands of days in the coldest waters(1). The degradation of methyl iodide in soils was not markedly affected by sterilization implying that degradation occurred by chemical mechanisms(5). The fact that degradation was considerably faster in organic matter-rich soils suggests that other reactions, probably with nucleophilic functional groups, are involved. The half-life in soils that were rich in organic matter was 9-13 days, while in a sandy loam soil it was 42-63 days.

An estimated BCF of 2.9 was calculated for methyl iodide(SRC), using a log Kow of 1.51(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low. While methyl iodide has been detected in various fish and shellfish, it is thought that the chemical may have been formed biogenically(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for methyl iodide can be estimated to be 14(SRC). According to a classification scheme(2), this estimated Koc value suggests that methyl iodide should have very high mobility in soil. The soil/water distribution coefficient of methyl iodide in various soils were (soil, Kd): Greenfield sandy loam, 0.09; Linne clay loam, 0.15; Carsetas loamy sand, 0.16; and potting mix, 0.55(3).

The Henry's Law constant for methyl iodide is 0.00526 atm-cu m/mole at 25 °C(1). This Henry's Law constant indicates that methyl iodide should volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 1.3 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 4.8 days(SRC). The Henry's Law constant in seawater of salinity 30.4 g dissolved inorganic matter/kg seawater was 0.00354 atm-cu m/mole at 20 °C(4) indicating a lower volatization rate for methyl iodide in seawater(SRC). Dissipation of methyl iodide from open surface water was found to be primarily a result of volatilization(4). Experiments conducted under indoor conditions resulted in a first-order half-life of 29 hours under static conditions and 6.5 hours when stirred at low speed with a magnetic stirrer(5). After 6 days, less that 1% of the methyl iodide was detected as iodide ion. Methyl iodide's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Methyl iodide is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 405 mm Hg at 25 °C(3).

Experiments were conducted to assess the volatilization loss of methyl iodide, applied at 30 cm, from 60-cm packed soil columns with different soils and under various soil surface conditions(1). In Greenfield sandy loam, the greatest cumulative loss occurred in nontarp applications, 94%, and the least in a high-barrier plastic tarp treatment, 75%. Volatilization losses with a polyethylene film was 90% and therefore this treatment was ineffective at preventing volatilization loss. Volatilization losses using a polyethylene film were significantly lower, 38% and 53%, from two soils high in organic matter and capable of rapidly degrading the chemical.

SURFACE WATER: Point Reyes, CA - nearshore 37 parts/trillion(1). Atlantic Ocean surface water 135 parts/trillion(2). The avg methyl iodide concn of seawater sampled in the eastern Pacific Ocean in 1981 was 1.6 ng/l(3). Methyl iodide concns were measured in water samples at 58 stations in the northwest Atlantic in April-May 1991(4). Offshore in the upper 50 m, concns ranged from <0.1 ng/l to 1 ng/l. Levels were relatively high near the Greenland coast, 2.2 ng/l but were relatively low off of Labrador. The highest concns (up to 8.7 ng/l) were seen in the shallow waters of the Grand Banks. Concns decreased sharply with depth, frequently with undetectable levels by 500 m.

Methyl iodide was detected (conc not reported) in air samples collected above a hazardous waste site in NJ(1); its presence is likely the result of volatile emissions from the site(1).

RURAL/REMOTE: US - 286 samples 0-9.2 parts/trillion, 6.7 parts/trillion median(1). Global background 1-3 parts/trillion(2). USEPA Volatile Organics Data Base: Mean concns (parts/trillion): 3 (remote), 7 (rural)(5). Concns of methyl iodide (parts/trillion) recorded during cruises (location/date, mean, range of concn): Western Pacific (n=48) - Sept-Oct. 1992, 0.87, 0.05-5.0; Eastern and southeast Asian seas (n=73) - Jan-Mar, 1994, 0.63, 0.24-2.0(6). 1994 winter measurements and 1991 summer measurements of methyl iodide were taken over the western Pacific basin. At latitudes >25 deg N, concns were typically between 0.4 and 0.8 parts/trillion(7). By contrast, concns were significantly lower in winter, remaining between 0.2 and 0.4 parts/trillion. Maximum concns in both seasons were below 3 km altitude. URBAN/SUBURBAN: US - 561 samples 3.5 parts/trillion median, 80 part/trillion max(1). USEPA Volatile Organics Data Base: Mean concns (parts/trillion): 7 (suburban), 2 (urban)(5). The following mean (range) concns (parts/trillion) of methyl iodide were monitored in the air of various US cities between 1983 and 1985(2): Philadelphia, PA, 3; Staten Island, NY, 5; Houston, TX, 12 (11-48); Downey, CA, 3 (<1-10); Denver, CO, 2 (1-8); San Jose, CA, 3-9 (<1-51)(2,4). Except for some measurements at Houston and under stagnant conditions in San Jose, methyl iodide concns were indistinguishable from natural background levels(2). Levels most frequently measurable in close proximity to the ocean were consistent with the suggestion that its origins are in the ocean(3). No significant man-made sources are known to exist(2).

Worldwide measurements show that methyl iodide is almost uniformly distributed over the oceans, with avg mixing ratios ranging between 0.002 and 0.003 ppb in the planetary boundary layer(1); in regions of high marine biomass production, avgs are roughly between 0.007 and 0.022 ppb(1); mixing ratios over the continents are generally lower than over the ocean(1).

Irish Sea - 3 species of mollusks 3-188 ppb methyliodide, 10 ppb median(1). Irish Sea - 5 species of fish 4-166 ppb, 17 ppb median(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 2182 workers (439 of these are female) are potentially exposed to methyl iodide in the US(1). Occupational exposure to methyl iodide may occur through inhalation and dermal contact with this compound at workplaces where it is produced or used(SRC). The general population may be exposed to methyl iodide via inhalation of ambient air or ingestion of food, primarily marine seafood(SRC).

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U138, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for liquid injection incineration at a temperature range of 650 to 1,600 °C and a residence time of 0.1 to 2 seconds. A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

If ... THERE IS NO FIRE, go directly to the Table of Initial Isolation and Protective Action Distances /(see table below)/ ... to obtain initial isolation and protective action distances. IF THERE IS A FIRE, or IF A FIRE IS INVOLVED, go directly to the appropriate guide /(see guide(s) below)/ and use the evacuation information shown under PUBLIC SAFETY.

Table: Table of Initial Isolation and Protective Action Distances for Methyl iodide [Table#3109]

/GUIDE 151: SUBSTANCES - TOXIC (Non-combustible)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.

/GUIDE 151: SUBSTANCES - TOXIC (Non-combustible)/ Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. 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 151: SUBSTANCES - TOXIC (Non-combustible)/ 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 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.

For more DOT Emergency Guidelines (Complete) data for METHYL IODIDE (9 total), please visit the HSDB record page.

UN 2644; Methyl iodide

IMO 6.1; Methyl iodide

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.

Poison Inhalation Hazard

Unbreakable packaging. Put breakable packaging into closed unbreakable container. Do not transport with food and feedstuffs.

Symbol: T; R: 21-23/25-37/38-40; S: (1/2)-36/37-38-45

UN Hazard Class: 6.1; UN Pack Group: I