Methacrolein

H225 (93.5%): Highly Flammable liquid and vapor [Danger Flammable liquids]

H301 (93.5%): Toxic if swallowed [Danger Acute toxicity, oral]

H311 (91.8%): Toxic in contact with skin [Danger Acute toxicity, dermal]

H314 (91.8%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H318 (63.5%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H330 (74.7%): Fatal if inhaled [Danger Acute toxicity, inhalation]

H341 (64.1%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H400 (64.1%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (64.1%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P203, P210, P233, P240, P241, P242, P243, P260, P262, P264, P264+P265, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P318, P320, P321, P330, P361+P364, P363, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 170 reports by companies from 11 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.

H225: Highly Flammable liquid and vapor [Danger Flammable liquids]

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

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

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

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

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

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

P210, P233, P240, P241, P242, P243, P260, P261, P262, P264, P264+P265, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P319, P320, P321, P330, P361+P364, P363, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Fresh air, rest.

Remove contaminated clothes. Rinse skin with plenty of water or shower. 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. Refer for medical attention .

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

Refer to the "General First Aid" section. Specific First Aid: Wash skin with soap and water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. (ERG, 2024)

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.

Specific First Aid:

· Wash skin with soap and water.

· In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin.

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

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient. CAUTION: Methanol (UN1230) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.).

SMALL FIRE: Dry chemical, CO2, water spray or alcohol-resistant foam.

LARGE FIRE: Water spray, fog or alcohol-resistant 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. 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)

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

CARBON DIOXIDE, ALC FOAM, FOAM, DRY CHEMICAL.

· 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.

· Ventilate closed spaces before entering, but only if properly trained and equipped.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· All equipment used when handling the product must be grounded.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

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

· A vapor-suppressing foam may be used to reduce vapors.

Small Spill

· Absorb with earth, sand or other non-combustible material and transfer to containers for later disposal.

· Use clean, non-sparking tools to collect absorbed material.

Large Spill

· Dike far ahead of liquid spill for later disposal.

· Water spray may reduce vapor, but may not prevent ignition in closed spaces.

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

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

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)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

· 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.

Consult an expert! Remove all ignition sources. Ventilation. Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Do NOT wash away into sewer. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Wash away remainder with plenty of water. Then store and dispose of according to local regulations.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

PRECAUTIONS FOR HANDLING REACTIVE UNSATURATED ALDEHYDES SUCH AS...METHACROLEIN...SHOULD BE SAME AS THOSE FOR OTHER HIGHLY ACTIVE EYE & PULMONARY IRRITANTS...

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors.

SMALL SPILL: Absorb with earth, sand or other non-combustible material and transfer to containers for later disposal. Use clean, non-sparking tools to collect absorbed material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024)

Fireproof. Separated from strong oxidants, acids, bases and food and feedstuffs. Cooled. Keep in the dark. Well closed. Keep under inert gas. Store only if stabilized. Provision to contain effluent from fire extinguishing.

· 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.

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: Final

0.20 [ppm]

0.33 [ppm]

3.5 [ppm]

CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.

CAUTION: Methanol (UN1230) will burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.)

Small Fire

· Dry chemical, CO2, water spray or alcohol-resistant foam.

Large Fire

· Water spray, fog or alcohol-resistant 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.

· 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.

A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20 °C.

The substance is irritating to the eyes, skin and respiratory tract.

Health effects of the substance have been investigated but none have been found

Excerpt from ERG Guide 131 [Flammable Liquids - Toxic; polymerization hazard]:

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. (ERG, 2024)

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Do NOT use compressed air for filling, discharging, or handling. Use non-sparking handtools.

PREVENT GENERATION OF MISTS!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety spectacles, face shield or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work.

Methacrylaldehyde appears as a colorless liquid. Less dense than water. May be toxic by ingestion, inhalation and skin absorption. Severely irritating to skin and eyes. Used to make plastics.

A colorless liquid with a characteristic odor; [ICSC]

COLOURLESS-TO-YELLOW LIQUID WITH PUNGENT ODOUR.

COLORLESS LIQUID

35 °F (NFPA, 2010)

35 °F (2 °C) (OPEN CUP)

MISCIBLE WITH WATER, ETHANOL, ETHER

Water solubility = 5.9% (59,000 mg/L) at 20 °C

Solubility in water, g/100ml at 20 °C: 6 (soluble)

0.849 @ 25 °C/4 °C

Relative density (water = 1): 0.8

0.830 @ 20°C

2.4 (AIR= 1)

Relative vapor density (air = 1): 2.42

155.0 [mmHg]

155 mm Hg @ 25 °C

Vapor pressure, kPa at 20 °C: 16

120 [mm Hg] @20 °C

DANGEROUS; ON DECOMPOSITION, EMITS TOXIC FUMES...

0.49 mPa.s @ 20 °C

0.59 mm²/s at 20 °C

2299 kJ/mol @ 25 °C

29.0 kJ/mol @ 101.3 kPa

Surface tension of the liquid at 77 °F = 23.41 dyne/cm.

INDEX OF REFRACTION: 1.4144 @ 20 °C/D; MAX ABSORPTION (ALCOHOL): 216 NM (LOG E= 4.04); SADTLER REF NUMBER: 8350

CONVERSION FACTORS: 1 MG/L= 349 PPM; 1 PPM= 2.8 MG/CU M

Liquid molar volume = 0.08320 cu m/kmol

Heat of Formation (gas) = -70.8 kJ/mol at 25 °C

Coriolis coupling

Schoenflies notation

Centrifugal distortion

Chemical bond

Equilibrium structure

Hindering potential

Internuclear distance

Molecular structure

Moment of inertia

Nuclear quadrupole coupling

Nuclear quadrupole moment

Optical coefficient

Highly flammable. Soluble in water.

Aldehydes

Acrylates and Acrylic Acids

Polymerizable Compounds

Highly Flammable

Polymerizable

METHACRYLALDEHYDE is an aldehyde. Aldehydes are frequently involved in self-condensation or polymerization reactions. These reactions are exothermic; they are often catalyzed by acid. Aldehydes are readily oxidized to give carboxylic acids. Flammable and/or toxic gases are generated by the combination of aldehydes with azo, diazo compounds, dithiocarbamates, nitrides, and strong reducing agents. Aldehydes can react with air to give first peroxo acids, and ultimately carboxylic acids. These autoxidation reactions are activated by light, catalyzed by salts of transition metals, and are autocatalytic (catalyzed by the products of the reaction). The addition of stabilizers (antioxidants) to shipments of aldehydes retards autoxidation.

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

Cough. Sore throat. Burning sensation.

Redness. Pain.

Redness. Pain. Burns. Watering of the eyes.

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

LCLo (rat) = 125 ppm/4H

LD50 Rat oral 0.14 g/kg /From table/

LD50 Rabbit skin 0.43 g/kg /From table/

METHACROLEIN WAS LESS CILIOSTATIC (IRRITATING TO TRACHEAL MUCOSA) THAN ACROLEIN.

The low molecular weight aldehydes, the halogenated aliphatic aldehydes, and the unsaturated aldehydes are particularly irritating. The mucus membranes of the nasal and oral passages and the upper respiratory tract are affected, producing a burning sensation, an increased ventilation rate, bronchial constriction, choking, and coughing. The eyes tear, and a burning sensation is noted on the skin of the face. During low exposures, the initial discomfort may abate after 5 to 10 minutes but will recur if exposure is resumed after an interruption. /Aldehydes/

...STRONG IRRITANT.

DEATH OCCURRED IN 5 OUT OF 6 RATS EXPOSED FOR 4 HR TO 250 PPM. WHEN RABBITS WERE EXPOSED TO METHACROLEIN, THERE WAS SLIGHT IRRITATION OF SKIN, BUT SEVERE IRRITATION OF EYES. /FROM TABLE/

Inhalation toxicity: rat, 250 ppm for 4 hours; mortality 5/6. /From table/

Irritant effects to rabbits: slight skin irritant, severe eye irritant. /From table/

The compound was tested externally on the eyes of rabbits, and, according to the degree of injury observed after 24 hours, rated on a scale of 1 to 10. The most severely injurious substances have been rated 10. Methacrylaldehyde rated 9 on rabbit eyes.

For more Non-Human Toxicity Excerpts (Complete) data for METHACROLEIN (6 total), please visit the HSDB record page.

The substance is very toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment.

Methacrolein's former production and use in copolymers, resins, and as an intermediate for the production of methacrylonitrile or methacrylic acid may have resulted in its release to the environment through various waste streams. It has been detected in the emissions from automobile exhaust, liquid floor wax, steel protective paints, and from trees. It also has been identified in urban and rural air samples, Chickpea seed, and in human adipose tissue. If released to soil, methacrolein will have very high mobility. Volatilization of methacrolein will be important from moist and dry soil surfaces. Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in soil or water. If released to water, methacrolein may not adsorb to suspended solids and sediment. Methacrolein may volatilize from water surfaces with estimated half-lives for a model river and model lake of about 5 hours and 4 days, respectively. An estimated BCF value of 1.4 suggests that methacrolein will not bioconcentrate in aquatic organisms. If released to the atmosphere, methacrolein will exist in the vapor phase. Vapor-phase methacrolein is degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 11.5 hours. Vapor-phase methacrolein is also degraded in the atmosphere by reaction with ozone with an estimated half-life of about 10.5 days. Methacrolein reacts very quickly in air with oxygen forming peroxides and acids. Methacrolein is formed from the gas-phase reaction of ozone with isoprene. Exposure to methacrolein may occur through dermal contact and inhalation. (SRC)

ONE OF THE COMPOUNDS IDENTIFIED IN THE SMOKE PRODUCED BY BURNING OF SHIPBOARD MATERIAL WAS METHACROLEIN.

Found in exhaust from API #7 gasoline in concentrations of 1.6 ppm

Found in exhaust from API #8 gasoline in concentrations of 0.9 ppm

Methacrolein's production and use in copolymers(1), resins(1), and as an intermediate for the production of methacrylonitrile or methacrylic acid(2) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 11.3(SRC), determined from an experimental water solubility(2) and a recommended regression-derived equation(3), indicates that methacrolein will have very high mobility in soil(SRC). Volatilization of methacrolein may be important from moist soil surfaces(SRC) given an estimated Henry's Law constant of 2.86X10-4 atm-cu m/mole, calculated from experimental values of vapor pressure(4) and water solubility(2), and from dry soil surfaces(SRC) based on an experimental vapor pressure of 155 mm Hg(4). Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in soil(SRC).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 11.3(SRC), determined from an experimental water solubility(2) and a recommended regression-derived equation(3), indicates that methacrolein may not adsorb to suspended solids and sediment(SRC) in the water. Methacrolein may volatilize from water surfaces based on an estimated Henry's Law constant of 2.86X10-4 atm-cu m/mole(SRC), calculated from experimental values of vapor pressure(4) and water solubility(2). Estimated half-lives for a model river and model lake are 5 hours and 4 days, respectively(3,SRC). An estimated BCF value of 1.4(3,SRC), from an experimental water solubility(2), suggests that methacrolein will not bioconcentrate in aquatic organisms(SRC) according to a recommended classification scheme(5). Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in water(SRC).

ATMOSPHERIC FATE: According to a suggested classification scheme(1), an experimental vapor pressure of 155 mm Hg at 25 °C(2) indicates that methacrolein will exist in the vapor phase in the ambient atmosphere. Vapor-phase methacrolein 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 about 11.5 hours(3,SRC). Vapor-phase methacrolein is also degraded in the atmosphere by reaction with ozone(SRC); the half-life for this reaction in air is estimated to be about 10.5 days(4,SRC). Methacrolein reacts very quickly in air with oxygen forming peroxides and acids(5). Methacrolein is formed from the gas-phase reaction of ozone with isoprene with a formation yield of 0.387(6).

The rate constant for the vapor-phase reaction of methacrolein with photochemically produced hydroxyl radicals has been experimentally determined to be 3.35X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 11.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The rate constant for the vapor-phase reaction of methacrolein with ozone has been experimentally determined to be 1.12X10-18 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 10.2 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2,SRC). Methacrolein reacts very quickly in air with oxygen forming peroxides and acids(3). Methacrolein is formed from the gas-phase reaction of ozone with isoprene with a formation yield of 0.387 at 296 deg K at 740 torr total pressure(4).

An estimated BCF value of 1.4 was calculated for methacrolein(SRC), using an experimental water solubility of 50,000 mg/L(1) and a recommended regression-derived equation(2). According to a recommended classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms will not be an important fate process(SRC).

The Koc of methacrolein is estimated as approximately 11.3(SRC), using an experimental water solubility of 50,000 mg/L(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that methacrolein has very high mobility in soil(SRC).

The Henry's Law constant for methacrolein is estimated as 1.9X10-4 atm-cu m/mole(SRC) from its experimental values for vapor pressure, 155 mm Hg(1), and water solubility, 50,000 mg/l(2). This value indicates that methacrolein will volatilize from water surfaces(3,SRC). 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) is estimated as approximately 5 hours(3,SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec) is estimated as approximately 4 days(3,SRC). Methacrolein's high vapor pressure(1) and Henry's Law constant(1,2,SRC) indicate that volatilization from dry and moist soil may occur(SRC).

Methacrolein has been reported to be released from gasoline exhaust(1). Methacrolein is formed from burning polyethylene which may occur in fire situations(2). Methacrolein emissions from a single-cylinder, production-type engine using isooctane fuel were 21 and less than 1 mole fraction with a 0.9 and 1.15 fuel-air equivalence ratio, respectively(3). Methacrolein has been detected as an emission from liquid floor wax(4). Methacrolein made up 1.6% of the total hydrocarbons released from a pulse flame combustor using methyl-t-butyl ether as fuel(5).

URBAN/SUBURBAN: Air samples from four urban sites in Stockholm contained methacrolein at the following average concentrations: 0.71, 0.19, 0.11, and 0.13 ppb(1).

RURAL/REMOTE: In a rural site, 12 km outside of Stockholm, the average methacrolein concentration was 0.06 ppb(1).

Methacrolein has been qualitatively detected as a volatile component of Chickpea (Cicer arietinum L) seed(1).

Methacrolein is emitted from Bay-leaved Willow, Aspen, Balsam poplar, European oak, Scots pine, and European larch(1).

Methacrolein is released upon thermal degradation of steel protective paints (350 °C) at the following amounts: from primers, 4, 1, and 7 mg/cu m (special, chlorinated rubber and alkyds); and finishing paints, 10 mg/cu m (alkyd)(1).

Exposure to methacrolein may occur through dermal contact and inhalation(1).

Methacrolein has been qualitatively detected in one out of 12 samples of human adipose tissue from a 0-14 age group in the Southern Region(1).

The substance is very toxic to aquatic organisms. It is strongly advised not to let the chemical enter into the environment.

Methacrolein's former production and use in copolymers, resins, and as an intermediate for the production of methacrylonitrile or methacrylic acid may have resulted in its release to the environment through various waste streams. It has been detected in the emissions from automobile exhaust, liquid floor wax, steel protective paints, and from trees. It also has been identified in urban and rural air samples, Chickpea seed, and in human adipose tissue. If released to soil, methacrolein will have very high mobility. Volatilization of methacrolein will be important from moist and dry soil surfaces. Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in soil or water. If released to water, methacrolein may not adsorb to suspended solids and sediment. Methacrolein may volatilize from water surfaces with estimated half-lives for a model river and model lake of about 5 hours and 4 days, respectively. An estimated BCF value of 1.4 suggests that methacrolein will not bioconcentrate in aquatic organisms. If released to the atmosphere, methacrolein will exist in the vapor phase. Vapor-phase methacrolein is degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 11.5 hours. Vapor-phase methacrolein is also degraded in the atmosphere by reaction with ozone with an estimated half-life of about 10.5 days. Methacrolein reacts very quickly in air with oxygen forming peroxides and acids. Methacrolein is formed from the gas-phase reaction of ozone with isoprene. Exposure to methacrolein may occur through dermal contact and inhalation. (SRC)

ONE OF THE COMPOUNDS IDENTIFIED IN THE SMOKE PRODUCED BY BURNING OF SHIPBOARD MATERIAL WAS METHACROLEIN.

Found in exhaust from API #7 gasoline in concentrations of 1.6 ppm

Found in exhaust from API #8 gasoline in concentrations of 0.9 ppm

Methacrolein's production and use in copolymers(1), resins(1), and as an intermediate for the production of methacrylonitrile or methacrylic acid(2) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 11.3(SRC), determined from an experimental water solubility(2) and a recommended regression-derived equation(3), indicates that methacrolein will have very high mobility in soil(SRC). Volatilization of methacrolein may be important from moist soil surfaces(SRC) given an estimated Henry's Law constant of 2.86X10-4 atm-cu m/mole, calculated from experimental values of vapor pressure(4) and water solubility(2), and from dry soil surfaces(SRC) based on an experimental vapor pressure of 155 mm Hg(4). Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in soil(SRC).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 11.3(SRC), determined from an experimental water solubility(2) and a recommended regression-derived equation(3), indicates that methacrolein may not adsorb to suspended solids and sediment(SRC) in the water. Methacrolein may volatilize from water surfaces based on an estimated Henry's Law constant of 2.86X10-4 atm-cu m/mole(SRC), calculated from experimental values of vapor pressure(4) and water solubility(2). Estimated half-lives for a model river and model lake are 5 hours and 4 days, respectively(3,SRC). An estimated BCF value of 1.4(3,SRC), from an experimental water solubility(2), suggests that methacrolein will not bioconcentrate in aquatic organisms(SRC) according to a recommended classification scheme(5). Insufficient data are available to determine the rate or importance of biodegradation of methacrolein in water(SRC).

ATMOSPHERIC FATE: According to a suggested classification scheme(1), an experimental vapor pressure of 155 mm Hg at 25 °C(2) indicates that methacrolein will exist in the vapor phase in the ambient atmosphere. Vapor-phase methacrolein 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 about 11.5 hours(3,SRC). Vapor-phase methacrolein is also degraded in the atmosphere by reaction with ozone(SRC); the half-life for this reaction in air is estimated to be about 10.5 days(4,SRC). Methacrolein reacts very quickly in air with oxygen forming peroxides and acids(5). Methacrolein is formed from the gas-phase reaction of ozone with isoprene with a formation yield of 0.387(6).

The rate constant for the vapor-phase reaction of methacrolein with photochemically produced hydroxyl radicals has been experimentally determined to be 3.35X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 11.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The rate constant for the vapor-phase reaction of methacrolein with ozone has been experimentally determined to be 1.12X10-18 cu cm/molecule-sec at 25 °C(2). This corresponds to an atmospheric half-life of about 10.2 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2,SRC). Methacrolein reacts very quickly in air with oxygen forming peroxides and acids(3). Methacrolein is formed from the gas-phase reaction of ozone with isoprene with a formation yield of 0.387 at 296 deg K at 740 torr total pressure(4).

An estimated BCF value of 1.4 was calculated for methacrolein(SRC), using an experimental water solubility of 50,000 mg/L(1) and a recommended regression-derived equation(2). According to a recommended classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms will not be an important fate process(SRC).

The Koc of methacrolein is estimated as approximately 11.3(SRC), using an experimental water solubility of 50,000 mg/L(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that methacrolein has very high mobility in soil(SRC).

The Henry's Law constant for methacrolein is estimated as 1.9X10-4 atm-cu m/mole(SRC) from its experimental values for vapor pressure, 155 mm Hg(1), and water solubility, 50,000 mg/l(2). This value indicates that methacrolein will volatilize from water surfaces(3,SRC). 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) is estimated as approximately 5 hours(3,SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec) is estimated as approximately 4 days(3,SRC). Methacrolein's high vapor pressure(1) and Henry's Law constant(1,2,SRC) indicate that volatilization from dry and moist soil may occur(SRC).

Methacrolein has been reported to be released from gasoline exhaust(1). Methacrolein is formed from burning polyethylene which may occur in fire situations(2). Methacrolein emissions from a single-cylinder, production-type engine using isooctane fuel were 21 and less than 1 mole fraction with a 0.9 and 1.15 fuel-air equivalence ratio, respectively(3). Methacrolein has been detected as an emission from liquid floor wax(4). Methacrolein made up 1.6% of the total hydrocarbons released from a pulse flame combustor using methyl-t-butyl ether as fuel(5).

URBAN/SUBURBAN: Air samples from four urban sites in Stockholm contained methacrolein at the following average concentrations: 0.71, 0.19, 0.11, and 0.13 ppb(1).

RURAL/REMOTE: In a rural site, 12 km outside of Stockholm, the average methacrolein concentration was 0.06 ppb(1).

Methacrolein has been qualitatively detected as a volatile component of Chickpea (Cicer arietinum L) seed(1).

Methacrolein is emitted from Bay-leaved Willow, Aspen, Balsam poplar, European oak, Scots pine, and European larch(1).

Methacrolein is released upon thermal degradation of steel protective paints (350 °C) at the following amounts: from primers, 4, 1, and 7 mg/cu m (special, chlorinated rubber and alkyds); and finishing paints, 10 mg/cu m (alkyd)(1).

Exposure to methacrolein may occur through dermal contact and inhalation(1).

Methacrolein has been qualitatively detected in one out of 12 samples of human adipose tissue from a 0-14 age group in the Southern Region(1).

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

/GUIDE 131P: 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. /Methacrylaldehyde; Methacrylaldehyde, inhibited; Methacrylaldehyde, stabilized/

/GUIDE 131P: 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. /Methacrylaldehyde; Methacrylaldehyde, inhibited; Methacrylaldehyde, stabilized/

/GUIDE 131P: FLAMMABLE LIQUIDS-TOXIC/ Public Safety: CALL Emergency Response Telephone Number ... . 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. /Methacrylaldehyde; Methacrylaldehyde, inhibited; Methacrylaldehyde, stabilized/

/GUIDE 131P: 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. /Methacrylaldehyde; Methacrylaldehyde, inhibited; Methacrylaldehyde, stabilized/

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

2396 131P

UN 2396; Methacrylaldehyde, stabilized

IMO 3.2; Methacrylaldehyde, stabilized

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.

Flammable Liquid Poison

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

UN Hazard Class: 3; UN Subsidiary Risks: 6.1; UN Pack Group: II