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SECTION 1. CHEMICAL IDENTIFICATION

CHEMINFO Record Number: 209
CCOHS Chemical Name: Methylamine, anhydrous

Synonyms:
Methylamine (non-specific name)
Monomethylamine
Aminomethane
Carbinamine
Methanamine
Methylamine gas

Chemical Name French: Méthylamine, anhydre
Chemical Name Spanish: Metilamina (anhidro)
CAS Registry Number: 74-89-5
UN/NA Number(s): 1061
RTECS Number(s): PF6300000
EU EINECS/ELINCS Number: 200-820-0
Chemical Family: Saturated aliphatic amine / primary alkyl amine / primary amino alkane / aliphatic monoamine / methylamine
Molecular Formula: C-H5-N
Structural Formula: CH3-NH2

SECTION 2. DESCRIPTION

Appearance and Odour:
Colourless gas at room temperature and atmospheric pressure. Characteristic fishy odour at concentrations up to 100 ppm and an ammonia-like or suffocating odour at high concentrations (100-500 ppm).(8,9) Absorbs moisture.

Odour Threshold:
4.7 ppm (6.1 mg/m3) (detection).(17) Wide range of values reported: 0.0009-4.68 ppm.(17)

Warning Properties:
NOT RELIABLE - Wide range of odour thresholds reported, ranging up to the same value as the TLV. Olfactory fatigue (reduced perception of odour) may occur.(13)

Composition/Purity:
Commercially available as an anhydrous gas with a minimum purity of 98%.(8) Depending on the manufacturing process some of the impurities that may be present are dimethylamine and trimethylamine, methyl halides, methanol, ammonia, and water.(5) This CHEMINFO review is for methylamine gas. For hazard assessment and control information for methylamine solutions, see the methylamine solutions CHEMINFO review.

Uses and Occurrences:
Methylamine is used mainly as an intermediate in organic synthesis and for water gel explosives, accelerators, pharmaceuticals, insecticides, herbicides, plasticizers, N-methylpyrrolidine, methylalkanolamines, surface active agents, and fungicides; in tanning; as a component of photographic developers and paint removers; as a fuel additive; in the production of dyes; as a polymerization inhibitor; and as a rocket propellant.(9,34)


SECTION 3. HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW:
Colourless gas at room temperature and atmospheric pressure. Characteristic fishy odour at concentrations up to 100 ppm and an ammonia-like odour at high concentrations (100-500 ppm). EXTREMELY FLAMMABLE GAS. Decomposes at high temperatures to form toxic gases, such as nitrogen oxides. COMPRESSED GAS. VERY TOXIC. May be fatal if inhaled. Extremely irritating to the respiratory tract. May cause lung injury--effects may be delayed. Low concentrations may cause a temporary visual disturbance known as "blue haze" or "halo vision". CORROSIVE to the eyes and skin. May cause blindness. May cause permanent scarring. May cause frostbite.



POTENTIAL HEALTH EFFECTS

Effects of Short-Term (Acute) Exposure

Inhalation:
Methylamine gas is severely irritating to the nose, throat and lungs. Methylamine is very toxic if inhaled and poses a very serious inhalation hazard.
Symptoms of exposure include sore throat, coughing, shortness of breath and difficultly breathing. Brief exposures to 20-100 ppm have been reported to cause irritation and a burning sensation in the nose and throat.(3, unconfirmed citing a personal communication) Another report describes irritation at 25 ppm.(1, unconfirmed) Brief exposure (15-minutes) to 140 ppm is expected to produce intolerable nose and throat irritation, based on animal information. Short-lived effects of headache, nausea, faintness and feelings of anxiety have been described (3), but cannot be verified.
With severe exposure, death may result from severe inflammation of the bronchi and lungs, and fluid accumulation in the lungs (pulmonary edema). Symptoms of pulmonary edema (tightness in the chest and shortness of breath) can develop up to 48 hours after exposure and are aggravated by physical exertion. No human case reports of pulmonary edema were located, but these effects have been observed in animal studies.

Skin Contact:
Methylamine gas is corrosive, based on animal information. Corrosive materials can cause redness, pain, inflammation, blistering, ulceration and permanent scarring.
In addition, contact with liquefied gas may cause frostbite. Symptoms of mild frostbite include numbness, prickling and itching in the affected area. Symptoms of more severe frostbite include a burning sensation and stiffness of the affected area. The skin may become waxy white or yellow. Blistering, tissue death and gangrene may also develop in severe cases.

Eye Contact:
Exposure to airborne or liquefied methylamine gas can cause severe eye irritation or corrosive injury. Brief exposures to 20-100 ppm can cause temporary irritation resulting in redness and tearing (3, unconfirmed citing a personal communication). Brief exposure (15-minutes) to 140 ppm is expected to produce intolerable eye irritation, based on animal information. At higher concentrations, inflammation of the eyes and blurred vision can occur. Permanent injury, including blindness could result, based on comparison to ethylamine.
Direct contact with the liquefied gas may cause freezing of the eye. Permanent eye damage or blindness could result.
Low airborne concentrations of many amines (e.g. diethylamine, dimethylamine and triethylamine) can cause a visual disturbance commonly known as "blue haze" or "halo vision". This effect results from temporary swelling of the surface of the eye.(12) In general, after about 1-3 hours of exposure, vision becomes foggy or blurred, objects might appear bluish and there may be halos around lights. Affected persons may not experience eye discomfort or pain. The effect normally clears up within a day and causes no permanent injury.(12,31) This visual disturbance could contribute to accidents.

Ingestion:
Not applicable. Anhydrous methylamine is a gas.

Effects of Long-Term (Chronic) Exposure

Lungs/Respiratory System:
Long-term exposure to relatively low concentrations may be irritating to the respiratory system (nose, throat and bronchi), due to the corrosive nature of methylamine.

Respiratory Sensitization:
It is not possible to conclude that methylamine is an occupational respiratory sensitizer, based on the available information.
One case of respiratory sensitization or chemical bronchitis has been reported. Exposure concentrations ranged from 2-60 ppm, but the duration of exposure is unknown.(1, unconfirmed) There are no further details available to evaluate this report.

Carcinogenicity:

There is no human or animal information available for exposure to methylamine alone.
In an animal study, an interaction between methylamine and sodium nitrite, to form carcinogenic nitrosamines, was observed.(29) The extent of this conversion and its relevance to human cancer has not yet been determined, but the authors of this study consider the risk negligible.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has not assigned a carcinogenicity designation to this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human or animal information available.

Reproductive Toxicity:
There is no human or animal information available.

Mutagenicity:
It is not possible to draw conclusions about the potential mutagenicity of methylamine, based on the available information. There is no information available from studies with humans or live animals. Positive results were obtained in one study using cultured animal cells, which used relatively high concentrations of methylamine. Negative results were obtained in bacteria.

Toxicologically Synergistic Materials:
Formation of carcinogenic nitrosamines was observed in animals following ingestion of methylamine and sodium nitrite solutions.(29) The authors consider the risk of developing gastric tumours from methylamine exposure to be negligible. There is no specific information available for methylamine gas.

Potential for Accumulation:
Methylamine is not expected to accumulate in the body. Methylamine is broken down (metabolized) to carbon dioxide and ammonia. The carbon dioxide is eventually expired into the air and the ammonia is released in the urine as urea. Some methylamine is also excreted unchanged in the urine.(14) Methylamine is a normal constituent of the body and occurs in food, particularly fish.(3)


SECTION 4. FIRST AID MEASURES

Inhalation:
This chemical is extremely flammable, corrosive and very toxic. Take proper precautions to ensure your own safety before attempting rescue (e.g. remove any sources of ignition, wear appropriate protective equipment, use the "buddy" system). Remove source of contamination or move victim to fresh air. If breathing is difficult, trained personnel should administer emergency oxygen. DO NOT allow victim to move about unnecessarily. Symptoms of pulmonary edema can be delayed up to 48 hours after exposure. Quickly transport victim to an emergency care facility.

Skin Contact:
GAS: If irritation occurs, remove victim from exposure and flush with lukewarm, gently flowing water for 5 minutes. If irritation persists, repeat flushing and immediately obtain medical attention. LIQUEFIED GAS: Avoid direct contact with this chemical. Wear chemical protective clothing, if necessary. As quickly and gently as possible, remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Immediately flush with lukewarm, gently flowing water for at least 30 minutes. DO NOT INTERRUPT FLUSHING. If necessary, and it can be done safely, continue flushing during transport to emergency care facility. If there are signs of frostbite, DO NOT attempt to rewarm the affected area on site. DO NOT rub area or apply dry heat. Gently remove clothing or jewelry that may restrict circulation. Carefully cut around clothing that sticks to the skin and remove the rest of the garment. Loosely cover the affected area with a sterile dressing. DO NOT allow the victim to drink alcohol or smoke. Quickly transport victim to an emergency care facility. Double bag, seal, label and leave contaminated clothing, shoes and leather goods at the scene for safe disposal.

Eye Contact:
GAS: If irritation from the gas occurs, remove victim from exposure and immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 5 minutes, while holding the eyelid(s) open. If irritation persists, repeat flushing and immediately obtain medical attention. LIQUEFIED GAS: Avoid direct contact. Wear chemical protective gloves, if necessary. Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for at least 30 minutes, while holding the eyelid(s) open. If a contact lens is present, DO NOT delay irrigation or attempt to remove the lens. Take care not to rinse contaminated water into the unaffected eye or onto the face. Neutral saline solution may be used as soon as it is available. DO NOT INTERRUPT FLUSHING. If necessary, continue flushing during transport to emergency care facility. Quickly transport victim to an emergency care facility.

Ingestion:
Ingestion is not an applicable route of exposure for gases.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures.
Some first aid procedures recommended above require advanced first aid training. Protocols for undertaking advanced procedures must be developed in consultation with a doctor and routinely reviewed.

All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.



SECTION 5. FIRE FIGHTING MEASURES

Flash Point:
-62 deg C (-80 deg F) (closed cup) (32); 0 deg C (32.5 deg F) (closed cup) (4,5)

Lower Flammable (Explosive) Limit (LFL/LEL):
4.9% (5,6)

Upper Flammable (Explosive) Limit (UFL/UEL):
20.7% (5,6)

Autoignition (Ignition) Temperature:
430 deg C (806 deg F) (5,6)

Sensitivity to Mechanical Impact:
Probably not sensitive. Stable material.

Sensitivity to Static Charge:
Mixtures of methylamine gas and air at concentrations in the flammable range can be ignited by a static discharge of sufficient energy.

Electrical Conductivity:
The electrical conductivity is estimated to be 4 x 10(7) pS/m at 0 deg C, based on comparison to ethylamine.(6)

Combustion and Thermal Decomposition Products:
Nitrogen oxides, ammonia, hydrogen cyanide, nitriles, isocyanates, nitrosamines, carbon monoxide, carbon dioxide and other irritating and toxic fumes may be formed in a fire.

Fire Hazard Summary:
Extremely flammable gas. Compressed gas. Can readily form explosive mixtures with air. A major release of anhydrous methylamine will produce a vapour cloud and chilled liquefied gas pool. The addition of water to this pool will cause a large increase in the rate of gas evolution. Water solutions are corrosive and will burn unless diluted sufficiently with water spray. During a fire, toxic gases may be generated. Can accumulate in confined spaces, resulting in an explosion and toxicity hazard. Heat from a fire can cause a rapid build-up of pressure inside cylinders, which may cause explosive rupture and a sudden release of large amounts of extremely flammable, corrosive, and toxic gas.

Extinguishing Media:
Dry chemical, alcohol resistant foam, water spray. Use water spray to keep fire exposed containers cool. Water may be ineffective because of the low flash point of methylamine.(6) Foam manufacturers should be consulted for recommendations regarding types of foams and application rates.

Extinguishing Media to be Avoided:
Carbon dioxide reacts with amines to form thermally unstable carbamate salts.

Fire Fighting Instructions:
Evacuate area. Fight fire from a protected location or maximum distance possible. Approach fire from upwind to avoid hazardous gas and toxic decomposition products. Wear full protective gear if exposure is possible. See advice in Protection of Firefighters.
For fires involving flammable gases, the best procedure is to stop the flow of gas before attempting to extinguish the fire. It is extremely dangerous to extinguish the fire, while allowing continued flow of the gas. The gas could form an explosive mixture with air and reignite, which may cause far more damage than if the original fire had been allowed to burn. In some cases, extinguishing the fire with dry chemical powder may be necessary to permit immediate access to valves to shut off the flow of gas. However, this must be done carefully. If it is not possible to stop the flow of gas and if there is no risk to the surrounding area, allow the fire to continue burning while protecting exposed materials with water spray, to prevent ignition of other combustible materials.
DO NOT direct water spray into liquefied gas. Gas clouds may be controlled by water spray or fog. The resulting water solutions of methylamine may be flammable, corrosive and very toxic. Dike fire control water for appropriate disposal.
Heat from a fire can cause a rapid build-up of pressure inside cylinders, which may cause explosive rupture. Withdraw immediately in case of rising sound from venting safety device or any discolouration of tank due to fire.
Cool fire-exposed cylinders, tanks, equipment or pipelines by applying hose streams, to minimize the risk of rupture. Cooling should begin as soon as possible (within several minutes) and should concentrate on any unwetted portions of the container. Apply water from the side and a safe distance. DO NOT direct water at open or leaking cylinders and take precautions not to get water inside a container or cylinder. Reverse flow into cylinder may cause rupture. No part of a cylinder should be subjected to a temperature higher than 52 deg C (approximately 125 deg F). Cooling should continue until well after the fire is out.
Isolate cylinders and other containers exposed to heat but not yet directly involved in the fire and protect personnel. Move cylinders from fire area only if this can be done without risk. Stay away from ends of tanks, but be aware that flying material (shrapnel) from ruptured tanks or cylinders may travel in any direction.
For an advanced or a massive fire in a large area, use unmanned hose holder or monitor nozzles; if this is not possible withdraw from fire area and allow fire to burn.
After the fire has been extinguished, the resulting water solutions of methylamine are corrosive and may be flammable. Corrosive and explosive atmospheres may be present. Before entering such an area, especially confined areas, check the atmosphere with an appropriate monitoring device while wearing full protective suit. Cylinders or tanks that have been involved in a fire, should not be approached until they have been completely cooled down.

Protection of Fire Fighters:
Methylamine and its decomposition products are extremely hazardous to health. Do not enter any fire area without specialized protective equipment suitable for the occasion. Firefighter's normal protective equipment (Bunker Gear) will not provide adequate protection. Chemical resistant clothing (e.g. chemical splash suit) and positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) may be necessary.



NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD IDENTIFICATION

NFPA - Health: 3 - Short exposure could cause serious temporary or residual injury.
NFPA - Flammability: 4 - Will rapidly or completely vaporize at atmospheric pressure and normal ambient temperature, or readily disperse in air and burn readily.
NFPA - Instability: 0 - Normally stable, even under fire conditions, and not reactive with water.

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Molecular Weight: 31.07

Conversion Factor:
1 ppm = 1.27 mg/m3; 1 mg/m3 = 0.789 ppm at 25 deg C (calculated)

Physical State: Gas
Melting Point: -93.4 deg C (-136.3 deg F) (liquefied gas) (7,8)
Boiling Point: -6.3 deg C (20.67 deg F) (liquefied gas) (7,8)
Relative Density (Specific Gravity): Not applicable (gas)
Solubility in Water: Very soluble (108 g/100 mL water) at 25 deg C (7,8)
Solubility in Other Liquids: Completely soluble in diethyl ether.(10) Soluble in ethyl alcohol, acetone, and benzene.(10,13)
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P(oct) = -0.57 (7)
pH Value: 11.8 (0.1 M solution) (calculated)
Basicity: Strong organic base.
Dissociation Constant: pKb = 3.35 at 25 deg C (13)
Viscosity-Dynamic: Not applicable
Surface Tension: Not applicable
Vapour Density: 1.08 (air = 1) (calculated)
Vapour Pressure: 300 kPa (2250 mm Hg) at 20 deg C (8); 352 kPa (2650 mm Hg) at 25 deg C (7)
Vapour Pressure at 50 deg C: Approximately 783 kPa (5888 mm Hg) at 50 deg C (9)
Saturation Vapour Concentration: Not applicable (gas)
Evaporation Rate: Gas at room temperature and pressure. Compressed liquefied gas rapidly evaporates upon contact with room air.
Henry's Law Constant: 1.12 Pa.m3/mol (cited as 1.11 x 10-5 atm.m3/mol at 25 deg C (7); log H = -3.34 (dimensionless constant; calculated)
Critical Temperature: 159 deg C (318 deg F) (7); 156.9 deg C (314 deg F) (9)
Critical Pressure: 7460 kPa (73.6 atm) (8,9)

Other Physical Properties:
DIELECTRIC CONSTANT: 11.4 at -11 deg C; 10 at 18 deg C (dimensionless) (4); 9.5 at 25 deg C (5)


SECTION 10. STABILITY AND REACTIVITY

Stability:
Normally stable.

Hazardous Polymerization:
Will not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.


STRONG OXIDIZERS (e.g. hydrogen peroxide, nitric acid, perchlorates, hypochlorites) - React violently with risk of fire or explosion. Reaction with hypochlorites forms unstable chloroamines, which may explode at room temperature.(36) Reaction with nitric acid is exothermic and may produce nitrogen gas rapidly, resulting in spattering of the corrosive mixture.(34,37) Reaction with nitrating agents (mixture of concentrated nitric and sulfuric acid) forms unstable N-nitro compounds that pose an explosion risk if subjected to shock or if heated rapidly and uncontrollably.(36)
STRONG ACIDS (e.g. hydrogen halides, sulfuric acid, chlorosulfonic acid) - Reaction is vigorous or violent.(36,37)
DIAZOTIZATION AGENTS (e.g. mixture of sodium nitrite and hydrochloric acid) - Forms unstable diazonium salts, which are explosive and sensitive to friction, shock, heat and radiation.(36)
MERCURY or NITROPHENOLS - Form shock-sensitive compounds.(8,36)
NITROMETHANE - Reaction product may detonate; organic amines and nitromethane form sensitive explosive mixtures.(36)
HALOGENATING AGENTS (e.g. chlorine gas, thionyl chloride) or LEWIS ACIDS (e.g. boron trichloride, aluminum chloride) - May react violently. May form shock sensitive chloroamines. May release toxic and corrosive gases (e.g. hydrogen chloride).(36,37)
ALKALI METALS (e.g. sodium, potassium), ALKALINE EARTH METALS (e.g. calcium, magnesium) or METAL HYDRIDES (e.g. lithium aluminum hydride or sodium hydride) - Release flammable hydrogen gas and a very strong corrosive base.
ACYLATING AGENTS (e.g. acetyl chloride, phosgene) or ALKYLHALIDES (e.g. benzylchloride or t-butylchloride) - Reaction at room temperature can form toxic and corrosive gases (e.g. hydrogen chloride). May evolve heat. Reaction with phosgene forms thermally unstable isocyanate compounds.(5,34)
EPOXIDES (e.g. ethylene oxide), CARBON DISULFIDE, ISOCYANATES, or ISOTHIOCYANATES - Reaction may be rapid and evolve heat.(5,34)
CARBON DIOXIDE - Forms thermally unstable amine carbamate salts.(34)

Hazardous Decomposition Products:
Forms corrosive solutions when exposed to water or moist air.

Conditions to Avoid:
Static discharge, sparks, other ignition sources.

Corrosivity to Metals:
Anhydrous methylamine is not corrosive to carbon steel, aluminum, cast iron, stainless steel (types 316, 317, 403, 410, 440), Hastelloy and tantalum. (24) It slowly attacks copper, copper-nickel, brass and bronze (corrosion rate less than 1.25 mm/year).(24)

Corrosivity to Non-Metals:
Anhydrous methylamine attacks polyvinylidene fluoride, polyvinyl chloride, polypropylene, acrylonitrile, polyimide, polyurethane, high density polyethylene, polyacetal, and thermoset polyester plastics.(33) Anhydrous methylamine does not attack Teflon and most other fluorinated plastics, polyamide, and thermoset epoxy plastics.(33)


SECTION 11. TOXICOLOGICAL INFORMATION

LC50 (female rat): 360 ppm (4-hour exposure); cited as 0.448 mL/L (2.5-hour exposure) (24-hour observation period) (21)
LC50 (mouse): 1322 ppm (4-hour exposure); cited as 1890 ppm (2-hour exposure) (11,20-unconfirmed)
LC50 (rat): approximately 2500 ppm (4-hour exposure); cited as 5000 ppm (estimated 1-hour LC50) (11, unconfirmed)

Skin Irritation:

Anhydrous methylamine is corrosive to the skin.

Methylamine gas was liquefied by immersing steel tubing connected to a cylinder of methylamine in a cooling bath of acetone and dry ice. Liquefied methylamine was obtained from the end of the tubing and 2-3 drops were allowed to fall on the skin of 3 guinea pigs. Two control animals were exposed to a similar volume of the acetone-dry bath. On contact with the skin, the methylamine rapidly vapourized leaving no surface residue. Within a few minutes, the skin turned purple and became swollen. At 48 hours, the test skin showed necrosis (tissue death). At 12 days, healing had occurred, but the tissue lacked hair follicles. Control animals only showed slight redness for a few minutes and at 48 hours the skin was normal.(22) Tissue death was also observed in rats exposed to airborne methylamine.(21)

Effects of Short-Term (Acute) Exposure:

Methylamine is very toxic and severely irritating to the respiratory tract following inhalation exposure. Life-threatening fluid accumulation in the lungs and deaths have been observed.

Inhalation:
Male mice exposed to 85-192 ppm methylamine for 15 minutes experienced a 50% reduction in respiratory rate (RD50) at 141 ppm. Changes in respiratory rate were noted within 30 seconds to 1 minute, and recovery took about 1 minute.(16) Exposure to the RD50 is expected to produce intolerable eye, nose and throat (sensory irritation) in humans. Female rats were exposed for 2.5 hours to 450 ppm (cited as 0.448 mL/L) methylamine released from a 40% solution. Symptoms included laboured breathing, shortness of breath, tearing and excitement. Tissue death (necrosis) was observed on the facial skin. Autopsy showed bleeding lungs.(21) Male rats were exposed to 465 ppm (cited as 19 micromoles/L) of methylamine for 30 minutes. While there were no resulting deaths and the rats appeared to be normal, internal examination revealed evidence of interstitial pneumonitis ( the chest cavity was filled with a blood clot and fluid comprising blood and serum).(27) Male rats were exposed (nose-only) to 75, 250 and 750 ppm methylamine for 2 weeks (6 hrs/d; 5 d/wk). At 750 ppm, signs of severe irritation including lung noise, laboured breathing, gasping, dry red discharges from the nose and eyes, and facial hair loss were observed. In this group, 4/10 rats died on the 8th or 10th day of exposure. During the 14-day recovery period, one additional rat in the 750 ppm group died. This group also showed signs of liver damage and changes in the blood forming (hematopoietic) system. Red nasal discharge was seen in all groups. At 75 ppm, mild irritation of the lining of the nose and at 250 ppm, more severe irritant effects, including ulceration in the nasal passages, were observed.(23) Exposure to 1500, 3000, 6000, 12000 and 24000 ppm for 1 hour caused death in 0/10, 2/10, 6/10, 10/10 and 10/10 rats, respectively. Examination of the dying rats showed congestion of the lungs, liver and mucous membranes of the upper respiratory system.(11, unconfirmed)

Effects of Long-Term (Chronic) Exposure:

Inhalation:
In a limited study, rats were exposed to 465 ppm (cited as 19 micromoles/L) of methylamine for 0.5 hrs/d for 1, 4 and 10 weeks. After one week of exposure, the lungs were pale in colour and were filled with clear fluid. Fluid accumulation was not observed at any other time (single 4-hr exposure, 4 weeks or 10 weeks). After 4 weeks, a moderate to severe irritation of the lung (interstitial pneumonitis), without fluid accumulation was observed. Severe interstitial pneumonitis that extended into the areas around the bronchus and surrounding blood vessels was observed after 10 weeks of exposure.(28) This study is limited by the small number of animals (4/group) and the fact that the animals were only exposed to one concentration of methylamine.

Carcinogenicity:
There is no information available on exposure to methylamine alone. Due to the known carcinogenic potential of nitrosamines, the in vivo conversion of amines, like methylamine, to nitrosamines is of interest. In one study, rats were force-fed solutions of radioactive methylamine hydrochloride and sodium nitrite. Chemical analysis of the rats' stomachs and small intestines showed that an interaction between methylamine and nitrite had occurred, resulting in DNA damage.(29) However, the extent of this conversion and its relevance to human cancer has not been determined. The authors of this study believe the risk to be negligible.

Mutagenicity:
It is not possible to draw conclusions on the potential mutagenicity of methylamine. No in vivo studies were located. Positive results were obtained in a test using cultured mammalian cells. Negative results were obtained in bacteria.
Positive results (forward mutations) were observed in cultured mouse lymphoma cells, without metabolic activation. Responses were seen at high concentrations (3-4 mM), in the absence of cytotoxicity.(26) Negative results were obtained in 4 strains of Salmonella typhimurium, in the presence and absence of metabolic activation.(25)

Toxicological Synergisms:
In the absence of metabolic activation, methylamine combined with nitrite was mutagenic in E. Coli.(30) Statistical analysis of the results was not presented. DNA damage was observed in rats orally exposed to methylamine and sodium nitrite.(29)


SECTION 16. OTHER INFORMATION

Selected Bibliography:
(1) Methylamine. Documentation of the threshold limit values and biological exposure indices. 7th ed. American Conference of Governmental Industrial Hygienists (ACGIH), 2001
(2) Methylamine. In: NIOSH pocket guide to chemical hazards. National Institute for Occupational Safety and Health. Available from World Wide Web: <http://www.cdc.gov/niosh/npg/npg.html>
(3) Cavender, F.L. Aliphatic and Alicyclic Amines. In: Patty's Industrial Hygiene and Toxicology. 5th ed. Edited by E. Bingham, et al. Vol. 4. John Wiley & Sons, 2001. p. 683-709, 805-815
(4) Dean, J.A. Lange's handbook of chemistry. 15th ed. McGraw-Hill, Inc., 1999. p. 1.245, 5.113
(5) August, B., et al. Methylamines. In: Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co, 2002. Available from World Wide Web: <http://www.mrw.interscience.wiley.com/ueic/ueic_search_fs.html>
(6) Fire protection guide to hazardous materials. 13th ed. Edited by A.B. Spencer, et al. National Fire Protection Association, 2002. NFPA 49; NFPA 77 (Ethylamine); 491 (Amines)
(7) Syracuse Research Corporation. The Physical Properties Database (PHYSPROP). Interactive PhysProp Database Demo. Date unknown. Available from World Wide Web: <http://www.syrres.com/esc/physdemo.htm>
(8) Handbook of compressed gases. Compressed Gas Association. 4th ed. Kluwer Academic Publishers, 1999. p. 498-508
(9) Yaws, C.L. Matheson gas data book. 7th ed. McGraw-Hill, 2001. p. 572-577, 879 (Appendix 5)
(10) Lide, D.R., ed. Handbook of chemistry and physics. 82nd ed. CRC Press, 2001. p. 3-205 (methanamine)
(11) Monomethylamine. Emergency Response Planning Guideline. American Industrial Hygiene Association (AIHA), 1989
(12) Grant, M.W., et al. Toxicology of the eye. 4th ed. Charles C. Thomas, 1993. p. 103-104, 963
(13) Methylamine. The Merck index: an encyclopedia of chemicals, drugs and biologicals. Edited by M.J. O'Neil, et al. 13th ed. Merck and Company, 2001. p. 1076
(14) Health-based recommended occupational exposure limits for ethylamine. Dutch Expert Committee for Occupational Standards, 1990
(15) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(16) Gagnaire, F., et al. Nasal irritation and pulmonary toxicity of aliphatic amines in mice. Journal of Applied Toxicology. Vol. 9, no. 5 (1989). p. 301-304
(17) Odor thresholds for chemicals with established occupational health standards. American Industrial Hygiene Association, 1989. p. 22, 66
(19) European Economic Community. Commission Directive 96/54/EC. July 30, 1996
(20) National Institute for Occupational Safety and Health (NIOSH). Methylamine. Last updated: 2002-10. In: Registry of Toxic Effects of Chemical Substances (RTECS(R)). [CD-ROM]. Canadian Centre for Occupational Health and Safety (CCOHS). Also available from World Wide Web: <http://ccinfoweb.ccohs.ca/rtecs/search.html>
(21) Sarkar, S.N., et al. Studies on the acute inhalation toxicity of methylamine vapours in rats. Journal of Environmental Biology. Vol. 13, no. 4 (1992). p. 273-276
(22) Goffman, T., et al. Cutaneous toxicity of liquified methylamine gas. Contact Dermatitis. Vol. 6, no. 6 (Jan. 1980). p. 140-141
(23) Kinney, L.A., et al. Inhalation toxicology of methylamine. Inhalation Toxicology. Vol. 2 (1990). p. 29-39
(24) Pruett, K.M. Chemical resistance guide to metals and alloys: a guide to chemical resistance of metals and alloys. Compass Publications, 1995. p. 206-217
(25) Mortelmans, K. et al. Salmonella mutagenicity tests: II. Results from the testing of 270 chemicals. Environmental Mutagenesis. Vol. 8, suppl. 7 (1986). p. 1-119
(26) Caspary, W.J. et al. Mutagenicity of methylisocyanate and its reaction products to cultured mammalian cells. Mutation Research. Vol. 174, no. 4 (Aug. 1986). p. 285-293
(27) Jeevaratnam, K. et al. Comparative toxicity of methyl isocyanate and its hydrolytic derivatives in rats. I. Pulmonary histopathology in the acute phase. Archives of Toxicology. Vol. 69, no. 1 (1994). p. 39-44
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Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.


Review/Preparation Date: 2004-11-03

Revision Indicators:
Appearance/odour 2005-04-18
First aid skin 2005-11-10
First aid eye 2005-11-10
Fire hazard summary 2005-11-22
Relative density 2006-09-28



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