HON. MARY NASH STODDARD GUEST LECTURER AT UNIVERSITY OF HOUSTON SCIENCE SYMPOSIUM (10/20/06)

Attention: #Aspartame #Alcohol #Addicts

Is This What You Want To Be Feeding Your Kids?

Every Molecule of ASPARTAME Sweeteners Contains 10% METHANOL:

Hazardous Substance Fact Sheet

Common Name: METHYL ALCOHOL

Synonyms: Carbinol; Wood Alcohol Chemical Name: Methanol Date: April 2002 Revision: September 2011

Methyl Alcohol is a colorless liquid with a slightly sweet, strong odor. It is used as a solvent and alternative motor fuel, and in making other chemicals, windshield washer fluid and de-icing solutions.

␣ODOR THRESHOLD = 100 to 1,500 ppm ␣Odor thresholds vary greatly. Do not rely on odor alone to

determine potentially hazardous exposures.

␣Methyl Alcohol is on the Right to Know Hazardous Substance List because it is cited by OSHA, ACGIH, DOT, NIOSH, IRIS, NFPA and EPA.

␣This chemical is on the Special Health Hazard Substance List.

CAS Number: RTK Substance Number: DOT Number:

67-56-1 1222 UN 1230

Description and Use

Hazard Summary

Hazard Rating

NJDHSS

NFPA

HEALTH

-

1

FLAMMABILITY

-

3

REACTIVITY

-

0

TERATOGEN FLAMMABLE POISONOUS GASES ARE PRODUCED IN FIRE CONTAINERS MAY EXPLODE IN FIRE

Reasons for Citation

SEE GLOSSARY ON PAGE 5.

FIRST AID

EMERGENCY RESPONDERS >>>> SEE LAST PAGE

Hazard Rating Key: 0=minimal; 1=slight; 2=moderate; 3=serious; 4=severe

␣Methyl Alcohol can affect you when inhaled and by passing through the skin.

␣Methyl Alcohol may be a TERATOGEN. HANDLE WITH EXTREME CAUTION.

␣Contact can cause skin irritation. Prolonged or repeated contact can cause a skin rash, dryness and redness.

␣Methyl Alcohol can irritate the eyes and can cause blurred vision and blindness.

␣Inhaling Methyl Alcohol can irritate the nose, throat and lungs causing coughing, wheezing and/or shortness of breath.

␣Methyl Alcohol can cause nausea, vomiting, diarrhea and abdominal pain.

␣Exposure to high concentrations can cause headache, dizziness, drowsiness, fatigue, loss of consciousness and death.

␣Methyl Alcohol may damage the liver, kidneys and nervous system.

␣Methyl Alcohol is a FLAMMABLE LIQUID and a DANGEROUS FIRE HAZARD.

Eye Contact

␣Immediately flush with large amounts of water for at least 15 minutes, lifting upper and lower lids. Remove contact lenses, if worn, while flushing. Seek medical attention.

Skin Contact

␣Quickly remove contaminated clothing. Immediately wash contaminated skin with large amounts of water. Seek medical attention.

Inhalation

␣Remove the person from exposure. ␣Begin rescue breathing (using universal precautions) if

breathing has stopped and CPR if heart action has stopped. ␣Transfer promptly to a medical facility.

EMERGENCY NUMBERS

Poison Control: 1-800-222-1222 CHEMTREC: 1-800-424-9300 NJDEP Hotline: 1-877-927-6337 National Response Center: 1-800-424-8802

OSHA:

The legal airborne permissible exposure limit (PEL) is 200 ppm averaged over an 8-hour workshift.

Workplace Exposure Limits

NIOSH: The recommended airborne exposure limit (REL) is 200 ppm averaged over a 10-hour workshift and 250 ppm, not to be exceeded during any 15-minute work period.

ACGIH: The threshold limit value (TLV) is 200 ppm averaged over an 8-hour workshift and 250 ppm as a STEL (short-term exposure limit).

␣Methyl Alcohol may be a TERATOGEN in humans. All contact with this chemical should be reduced to the lowest possible level.

␣The above exposure limits are for air levels only. When skin contact also occurs, you may be overexposed, even though air levels are less than the limits listed above.

METHYL ALCOHOL

Page 2 of 6

Determining Your Exposure

␣Read the product manufacturer's Material Safety Data Sheet (MSDS) and the label to determine product ingredients and important safety and health information about the product mixture.

␣For each individual hazardous ingredient, read the New Jersey Department of Health and Senior Services Hazardous Substance Fact Sheet, available on the RTK Program website (www.nj.gov/health/eoh/rtkweb) or in your facility's RTK Central File or Hazard Communication Standard file.

␣You have a right to this information under the New Jersey Worker and Community Right to Know Act and the Public Employees Occupational Safety and Health (PEOSH) Act if you are a public worker in New Jersey, and under the federal Occupational Safety and Health Act (OSHA) if you are a private worker.

␣The New Jersey Right to Know Act requires most employers to label chemicals in the workplace and requires public employers to provide their employees with information concerning chemical hazards and controls. The federal OSHA Hazard Communication Standard (29 CFR 1910.1200) and the PEOSH Hazard Communication Standard (N.J.A.C. 12:100-7) require employers to provide similar information and training to their employees.

This Fact Sheet is a summary of available information regarding the health hazards that may result from exposure. Duration of exposure, concentration of the substance and other factors will affect your susceptibility to any of the potential effects described below.

Acute Health Effects

The following acute (short-term) health effects may occur immediately or shortly after exposure to Methyl Alcohol:

␣Contact can cause skin irritation. ␣Methyl Alcohol can irritate the eyes and can cause blurred

vision and blindness. ␣Inhaling Methyl Alcohol can irritate the nose, throat and

lungs causing coughing, wheezing and/or shortness of

breath. ␣Methyl Alcohol can cause nausea, vomiting, diarrhea and

abdominal pain. ␣Exposure to high concentrations can cause headache,

dizziness, drowsiness, fatigue, loss of consciousness and death.

Chronic Health Effects

The following chronic (long-term) health effects can occur at some time after exposure to Methyl Alcohol and can last for months or years:

Cancer Hazard

␣There is no evidence that Methyl Alcohol causes cancer in animals. This is based on test results presently available to the NJDHSS from published studies.

Reproductive Hazard

␣Methyl Alcohol may be a TERATOGEN in humans since it is a teratogen in animals.

Other Effects

␣Prolonged or repeated contact can cause a skin rash, dryness, redness and cracking of the skin.

␣Methyl Alcohol may damage the liver, kidneys and nervous system.

Medical Testing

For frequent or potentially high exposure (half the PEL or greater), the following are recommended before beginning work and at regular times after that:

␣Liver function tests If symptoms develop or overexposure is suspected, the

following are recommended:

␣Kidney function tests ␣Exam of the nervous system ␣Exam of the eye and vision.

Any evaluation should include a careful history of past and present symptoms with an exam. Medical tests that look for damage already done are not a substitute for controlling exposure.

Request copies of your medical testing. You have a legal right to this information under the OSHA Access to Employee Exposure and Medical Records Standard (29 CFR 1910.1020).

Mixed Exposures

␣More than light alcohol consumption can cause liver damage. Drinking alcohol can increase the liver damage caused by Methyl Alcohol.

Medical

Health Hazard Information

METHYL ALCOHOL

Page 3 of 6

Workplace Controls and Practices

Very toxic chemicals, or those that are reproductive hazards or sensitizers, require expert advice on control measures if a less toxic chemical cannot be substituted. Control measures include: (1) enclosing chemical processes for severely irritating and corrosive chemicals, (2) using local exhaust ventilation for chemicals that may be harmful with a single exposure, and (3) using general ventilation to control exposures to skin and eye irritants. For further information on workplace controls, consult the NIOSH document on Control Banding at www.cdc.gov/niosh/topics/ctrlbanding/.

The following work practices are also recommended:

␣Label process containers. ␣Provide employees with hazard information and training. ␣Monitor airborne chemical concentrations. ␣Use engineering controls if concentrations exceed

recommended exposure levels. ␣Provide eye wash fountains and emergency showers. ␣Wash or shower if skin comes in contact with a hazardous

material. ␣Always wash at the end of the workshift. ␣Change into clean clothing if clothing becomes

contaminated. ␣Do not take contaminated clothing home. ␣Get special training to wash contaminated clothing. ␣Do not eat, smoke, or drink in areas where chemicals are

being handled, processed or stored. ␣Wash hands carefully before eating, smoking, drinking,

applying cosmetics or using the toilet.

In addition, the following may be useful or required:

␣Before entering a confined space where Methyl Alcohol may be present, check to make sure that an explosive concentration does not exist.

The OSHA Personal Protective Equipment Standard (29 CFR 1910.132) requires employers to determine the appropriate personal protective equipment for each hazard and to train employees on how and when to use protective equipment.

The following recommendations are only guidelines and may not apply to every situation.

Gloves and Clothing ␣Avoid skin contact with Methyl Alcohol. Wear personal

protective equipment made from material that can not be permeated or degraded by this substance. Safety equipment suppliers and manufacturers can provide recommendations on the most protective glove and clothing material for your operation.

␣The recommended glove materials for Methyl Alcohol are Butyl, Viton and Barrier®.

␣The recommended protective clothing materials for Methyl Alcohol are Tychem® SL, CSM and TK; and Trellchem® HPS and VPS, or the equivalent.

␣All protective clothing (suits, gloves, footwear, headgear) should be clean, available each day, and put on before work.

Eye Protection

␣Wear indirect vent goggles when working with liquids that may splash, spray or mist. A face shield is also required if the liquid is severely irritating or corrosive to the skin and eyes.

␣Do not wear contact lenses when working with this substance.

Respiratory Protection

Improper use of respirators is dangerous. Respirators should only be used if the employer has implemented a written program that takes into account workplace conditions, requirements for worker training, respirator fit testing, and medical exams, as described in the OSHA Respiratory Protection Standard (29 CFR 1910.134).

␣Where the potential exists for exposure over 200 ppm, use a NIOSH approved supplied-air respirator with a full facepiece operated in a pressure-demand or other positive-pressure mode. For increased protection use in combination with an auxiliary self-contained breathing apparatus or an emergency escape air cylinder.

␣Exposure to 6,000 ppm is immediately dangerous to life and health. If the possibility of exposure above 6,000 ppm exists, use a NIOSH approved self-contained breathing apparatus with a full facepiece operated in a pressure- demand or other positive-pressure mode equipped with an emergency escape air cylinder.

If employees are expected to fight fires, they must be trained and equipped as stated in the OSHA Fire Brigades Standard (29 CFR 1910.156).

␣Methyl Alcohol is a FLAMMABLE LIQUID. ␣Use dry chemical, CO2, water spray or alcohol-resistant

foam as extinguishing agents. ␣Water may not be effective in fighting fires. ␣POISONOUS GASES ARE PRODUCED IN FIRE. ␣CONTAINERS MAY EXPLODE IN FIRE. ␣Use water spray to keep fire-exposed containers cool. ␣Vapor is heavier than air and may travel a distance to cause

a fire or explosion far from the source and flash back. ␣Methyl Alcohol may form an ignitable vapor/air mixture in

closed tanks or containers.

Fire Hazards

Personal Protective Equipment

METHYL ALCOHOL

Page 4 of 6

Spills and Emergencies

Occupational Health Information

Resources

If employees are required to clean-up spills, they must be properly trained and equipped. The OSHA Hazardous Waste Operations and Emergency Response Standard (29 CFR 1910.120) may apply.

If Methyl Alcohol is spilled or leaked, take the following steps:

␣Evacuate personnel and secure and control entrance to the area.

␣Eliminate all ignition sources. ␣Absorb liquids in dry sand, earth, or a similar material and

place into sealed containers for disposal. ␣Ventilate area of spill or leak. ␣Keep Methyl Alcohol out of confined spaces, such as

sewers, because of the possibility of an explosion. ␣It may be necessary to contain and dispose of Methyl

Alcohol as a HAZARDOUS WASTE. Contact your state Department of Environmental Protection (DEP) or your regional office of the federal Environmental Protection Agency (EPA) for specific recommendations.

Prior to working with Methyl Alcohol you should be trained on its proper handling and storage.

␣Methyl Alcohol reacts violently or explosively with OXIDIZING AGENTS (such as PERCHLORATES, PEROXIDES, PERMANGANATES, CHLORATES, NITRATES, CHLORINE, BROMINE and FLUORINE); ALKYL ALUMINUM SALTS; ACETYL BROMIDE; CHROMIC ANHYDRIDE; MIXTURES of CHLOROFORM and SODIUM HYROXIDE; PHOSPHORUS TRIOXIDE; MIXTURES of SULFURIC ACID and HYDROGEN PEROXIDE; ISOCYANATES; METALS (such as LEAD, MAGNESIUM and POTASSIUM); and NITRIC ACID.

␣Methyl Alcohol attacks some PLASTICS, RUBBERS and COATINGS.

␣Store in tightly closed containers in a cool, well-ventilated area away from HEAT SOURCES.

␣Sources of ignition, such as smoking and open flames, are prohibited where Methyl Alcohol is used, handled, or stored.

␣Metal containers involving the transfer of Methyl Alcohol should be grounded and bonded.

␣Use explosion-proof electrical equipment and fittings wherever Methyl Alcohol is used, handled, manufactured, or stored.

␣Use only non-sparking tools and equipment, especially when opening and closing containers of Methyl Alcohol.

The New Jersey Department of Health and Senior Services, Occupational Health Service, offers multiple services in occupational health. These services include providing informational resources, educational materials, public presentations, and industrial hygiene and medical investigations and evaluations.

For more information, please contact:

New Jersey Department of Health & Senior Services Right to Know Program PO Box 368 Trenton, NJ 08625-0368

Phone: 609-984-2202 Fax: 609-984-7407 E-mail: rtk@doh.state.nj.us Web address: http://www.nj.gov/health/eoh/rtkweb

The Right to Know Hazardous Substance Fact Sheets are not intended to be copied and sold for commercial purposes.

Handling and Storage

METHYL ALCOHOL GLOSSARY

ACGIH is the American Conference of Governmental Industrial Hygienists. They publish guidelines called Threshold Limit Values (TLVs) for exposure to workplace chemicals.

Acute Exposure Guideline Levels (AEGLs) are established by the EPA. They describe the risk to humans resulting from once-in-a lifetime, or rare, exposure to airborne chemicals.

Boiling point is the temperature at which a substance can change its physical state from a liquid to a gas.

A carcinogen is a substance that causes cancer. The CAS number is unique, identifying number, assigned by

the Chemical Abstracts Service, to a specific chemical.

CFR is the Code of Federal Regulations, which are the regulations of the United States government.

A combustible substance is a solid, liquid or gas that will burn. A corrosive substance is a gas, liquid or solid that causes

destruction of human skin or severe corrosion of containers.

The critical temperature is the temperature above which a gas cannot be liquefied, regardless of the pressure applied.

DEP is the New Jersey Department of Environmental Protection.

DOT is the Department of Transportation, the federal agency that regulates the transportation of chemicals.

EPA is the Environmental Protection Agency, the federal agency responsible for regulating environmental hazards.

ERG is the Emergency Response Guidebook. It is a guide for emergency responders for transportation emergencies involving hazardous substances.

Emergency Response Planning Guideline (ERPG) values provide estimates of concentration ranges where one reasonably might anticipate observing adverse effects.

A fetus is an unborn human or animal. A flammable substance is a solid, liquid, vapor or gas that will

ignite easily and burn rapidly.

The flash point is the temperature at which a liquid or solid gives off vapor that can form a flammable mixture with air.

IARC is the International Agency for Research on Cancer, a scientific group.

Ionization Potential is the amount of energy needed to remove an electron from an atom or molecule. It is measured in electron volts.

IRIS is the Integrated Risk Information System database on human health effects that may result from exposure to various chemicals, maintained by federal EPA.

Page 5 of 6

LEL or Lower Explosive Limit, is the lowest concentration of a combustible substance (gas or vapor) in the air capable of continuing an explosion.

mg/m3 means milligrams of a chemical in a cubic meter of air. It is a measure of concentration (weight/volume).

A mutagen is a substance that causes mutations. A mutation is a change in the genetic material in a body cell. Mutations can lead to birth defects, miscarriages, or cancer.

NFPA is the National Fire Protection Association. It classifies substances according to their fire and explosion hazard.

NIOSH is the National Institute for Occupational Safety and Health. It tests equipment, evaluates and approves respirators, conducts studies of workplace hazards, and proposes standards to OSHA.

NTP is the National Toxicology Program which tests chemicals and reviews evidence for cancer.

OSHA is the federal Occupational Safety and Health Administration, which adopts and enforces health and safety standards.

PEOSHA is the New Jersey Public Employees Occupational Safety and Health Act, which adopts and enforces health and safety standards in public workplaces.

Permeated is the movement of chemicals through protective materials.

ppm means parts of a substance per million parts of air. It is a measure of concentration by volume in air.

Protective Action Criteria (PAC) are values established by the Department of Energy and are based on AEGLs and ERPGs. They are used for emergency planning of chemical release events.

A reactive substance is a solid, liquid or gas that releases energy under certain conditions.

STEL is a Short Term Exposure Limit which is usually a 15- minute exposure that should not be exceeded at any time during a work day.

A teratogen is a substance that causes birth defects by damaging the fetus.

UEL or Upper Explosive Limit is the highest concentration in air above which there is too much fuel (gas or vapor) to begin a reaction or explosion.

Vapor Density is the ratio of the weight of a given volume of one gas to the weight of another (usually Air), at the same temperature and pressure.

The vapor pressure is a force exerted by the vapor in equilibrium with the solid or liquid phase of the same substance. The higher the vapor pressure the higher concentration of the substance in air.

Right to Know Hazardous Substance Fact Sheet

Common Name: METHYL ALCOHOL

Synonyms: Carbinol; Methanol; Wood Alcohol CAS No: 67-56-1 Molecular Formula: CH3OH RTK Substance No: 1222

Description: Colorless liquid with a slightly sweet, strong odor

HAZARD DATA

Hazard Rating Firefighting Reactivity

1 - Health 3 - Fire 0 - Reactivity

DOT#: UN 1268 ERG Guide #: 131 Hazard Class: 3 (Flammable liquid)

Methyl Alcohol is a FLAMMABLE LIQUID.

Use dry chemical, CO2, water spray or alcohol-resistant foam as extinguishing agents.

Water may not be effective in fighting fires. POISONOUS GASES ARE PRODUCED IN FIRE.

CONTAINERS MAY EXPLODE IN FIRE. Use water spray to keep fire-exposed containers cool. Vapor is heavier than air and may travel a distance to

cause a fire or explosion far from the source and flash back.

Methyl Alcohol may form an ignitable vapor/air mixture in closed tanks or containers.

Methyl Alcohol reacts violently or explosively with OXIDIZING AGENTS (such as PERCHLORATES, PEROXIDES, PERMANGANATES, CHLORATES, NITRATES, CHLORINE, BROMINE and FLUORINE); ALKYL ALUMINUM SALTS; ACETYL BROMIDE; CHROMIC ANHYDRIDE; MIXTURES of CHLOROFORM and SODIUM HYROXIDE; PHOSPHORUS TRIOXIDE; MIXTURES of SULFURIC ACID and HYDROGEN PEROXIDE; ISOCYANATES; METALS (such as LEAD, MAGNESIUM and POTASSIUM); and NITRIC ACID.

Methyl Alcohol attacks some PLASTICS, RUBBERS and COATINGS.

PHYSICAL PROPERTIES

100 to 1,500 ppm 52oF (11oC) 6% 36%

867oF (464oC) 1.1 (air = 1) 96 mm Hg at 68oF (20oC) 0.8 (water = 1) Soluble 147oF (64oC) -144oF (-97.8oC) 10.84 eV 32.04

SPILL/LEAKS

Isolation Distance:

Spill: 50 meters (150 feet)

Fire: 800 meters (1/2 mile)

Absorb liquids in dry sand, earth, or a similar material and place into sealed containers for disposal.

Use only non-sparking tools and equipment. Metal containers involving the transfer of Methyl

Alcohol should be grounded and bonded. Keep Methyl Alcohol out of confined spaces, such as

sewers, because of the possibility of an explosion.

Odor Threshold: Flash Point: LEL: UEL:

Auto Ignition Temp: Vapor Density: Vapor Pressure: Specific Gravity: Water Solubility: Boiling Point: Melting Point: Ionization Potential: Molecular Weight:

OSHA: NIOSH: ACGIH: IDLH:

EXPOSURE LIMITS

200 ppm, 8-hr TWA 200 ppm, 10-hr TWA; 250 ppm Ceiling 200 ppm, 8-hr TWA; 250 ppm Ceiling 6,000 ppm

Gloves: Coveralls:

Respirator:

PROTECTIVE EQUIPMENT

Butyl, Viton and Barrier® (>8-hr breakthrough)

Tychem® SL, CSM and TK; Trellchem® HPS and VPS (>8-hr breakthrough) Use turn out gear or flash protection if ignition/fire is the greatest hazard.

>200 ppm - SCBA

The Protective Action Criteria values are: PAC-1 = 530 ppm PAC-2 = 2,100 ppm

Eyes: Skin: Inhalation:

PAC-3 = 7,200 ppm

HEALTH EFFECTS

Irritation, blurred vision and blindness. Irritation

Nose, throat and lung irritation with coughing, wheezing and shortness of breath

Headache, dizziness, drowsiness, loss of consciousness and death

FIRST AID AND DECONTAMINATION

Remove the person from exposure. Flush eyes with large amounts of water for at least 15 minutes. Remove contact

lenses if worn. Seek medical attention. Quickly remove contaminated clothing and wash contaminated skin with large

amounts of water. Seek medical attention. Begin artificial respiration if breathing has stopped and CPR if necessary. Transfer promptly to a medical facility.

September 2011

#METHANOL is 10% of every #ASPARTAME MOLECULE
(Can pose danger in Transportation causing Accidents to Occur from: #Pilots, #Train_Engineers, #Truck_Drivers, etc.)

[Ed. For every molecule of aspartame - there is a molecule of methanol released. Aspartame is 10% methanol by weight. A diet soda sweetened with aspartame contains 225 mg aspartame - 22.5 mg methanol. ]

Methanol

Last Updated: March 15, 2007

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Synonyms and related keywords: organic solvent, formaldehyde, formate, alcohol dehydrogenase, ADH, methanol ingestion, methanol toxicity, methanol intoxication, antifreeze ingestion, perfume ingestion, paint solvent ingestion, photocopying fluid ingestion, windshield washing fluid ingestion, shellac ingestion, inhalation of methanol, methanol fumes, methanol poisoning

AUTHOR INFORMATION 

Section 1 of 10     

Author Information  Introduction  Clinical  Differentials  Workup  Treatment  Medication  Follow-up  Miscellaneous  Bibliography

 Author: Kalyani Korabathina, MD, Department of Neurology, University of South Florida College of Medicine

 Coauthor(s): Selim R Benbadis, MD, Professor of Neurology, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida College of Medicine, Tampa General Hospital; David Likosky, MD, Clinical Instructor, Department of Neurology, University of Washington

 Kalyani Korabathina, MD, is a member of the following medical societies: American Academy of Neurology

 Editor(s): Jonathan S Rutchik, MD, MPH, Assistant Professor, Department of Occupational and Environmental Medicine, University of California at San Francisco; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine;  Nestor Galvez-Jimenez, MD, Program Director of Movement Disorders, Director of Neurology Residency Training Program, Department of Neurology, Division of Medicine, Cleveland Clinic Florida;  Matthew J Baker, MD, Consulting Staff, Collier Neurologic Specialists, Naples Community Hospital; and  Nicholas Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants

 Disclosure Author Information  Introduction  Clinical  Differentials  Workup  Treatment  Medication  Follow-up  Miscellaneous  Bibliography

Background: Methanol, also known as wood alcohol, is a commonly used organic solvent, the ingestion of which has severe potential ramifications. It is a constituent in many commercially available industrial solvents and in poorly adulterated alcoholic beverages. Toxicity usually occurs from intentional overdose or accidental ingestion and results in metabolic acidosis, neurologic sequelae, and even death. Methanol toxicity remains a common problem in many parts of the developing world, especially among members of lower socioeconomic classes.

Sophisticated imaging techniques have enabled a better understanding of the clinical manifestations of methanol toxicity. Additionally, with the improvement in medical therapy, neurological complications are recognized more frequently. This is possible because of early recognition of the toxicity and because of advances in supportive care. Hemodialysis and better management of acid-base disturbances remain the most important improvements.

Pathophysiology: Methanol has a relatively low toxicity. The adverse effects are thought to be from the accumulation of formic acid, a metabolite of methanol metabolism.

Upon ingestion, methanol is quickly absorbed in the gastrointestinal tract and metabolized in the liver. In the first step of degradation, methanol is transformed to formaldehyde via the enzyme alcohol dehydrogenase (ADH). This reaction is slower than the next step, the transformation of formaldehyde to formic acid via the enzyme aldehyde dehydrogenase. This may explain the reason for the latency of symptoms between ingestion and effect. The half-life of formaldehyde is estimated to be 1-2 minutes (Rathi, 2006).

Formic acid is further oxidized to carbon dioxide and water in the presence of tetrahydrofolate. The metabolism of formic acid is very slow; thus, it often accumulates in the body, which results in metabolic acidosis (Rathi, 2006).

The eye damage caused by methanol has been well described; however, the mechanism behind this phenomenon is not well understood. The major damage occurs at the retrolaminar optic nerve with intra-axonal swelling and organelle destruction. Little to no change is seen in the retina (Casarett, 1996).

Methanol also affects the basal ganglia. With severe intoxication, common problems are hemorrhagic and nonhemorrhagic damage of the putamen. This was described initially in 1953, although the clinical syndrome associated with this lesion was not described until more recently (Phang, 1988). As a result, patients can develop parkinsonism or other dystonic/hypokinetic clinical pictures.

The predilection for and mechanism of toxicity to the putamen is not understood. Some postulate that striatal neurons have a varying sensitivity to toxic metabolites of methanol. However, this remains to be proven (LeWitt, 1988).

In addition, cases of axonal polyneuropathy in association with chronic exposure have been reported (Hageman, 1999). Further, motor neuron disease resembling amyotrophic lateral sclerosis has been documented in 1 case report (Chio, 2004).

Mortality/Morbidity: 

•  Exact rates of morbidity and mortality from intoxication are not available.

•  Prognosis is correlated with the degree of metabolic acidosis (and the quantity of methanol ingested); more severe acidosis confers a poorer prognosis.

•  Direct correlation exists between the formic acid concentration and the morbidity and mortality.

CLINICAL 

Section 3 of 10     

Author Information  Introduction  Clinical  Differentials  Workup  Treatment  Medication  Follow-up  Miscellaneous  Bibliography

History:

•  Time course

?  Initial symptoms generally occur 12-24 hours after ingestion.

?  The interval between ingestion and the appearance of symptoms is correlated with the volume of methanol ingested and the amount of ethanol concomitantly ingested; competitive inhibition exists between the two (Rathi, 2006). Methanol blood levels peak at 30-90 minutes following ingestion and are often not correlated with time to symptom appearance. The minimal lethal dose in adults is believed to be 1 mg/kg of body weight.

?  In cases of altered mental status and intentional overdose, the diagnosis may be difficult without a high clinical index of suspicion.

•  Neurological manifestations

?  Initially, the symptoms from methanol intoxication are similar to those of ethanol intoxication, often with disinhibition and ataxia.

?  Following a latent period, patients may develop headache, nausea, vomiting, or epigastric pain.

?  In later stages, drowsiness may rapidly progress to obtundation and coma.

?  Seizures may occur, generally as a complication of the metabolic derangement or as a result of damage to the brain parenchyma.

?  Methanol appears to affect the basal ganglia, primarily the putamen. With advanced neuroimaging techniques, the putaminal damage is detected much earlier in current practice than in the past.

•  Vision loss

?  Blindness from methanol inhalation was described as early as 1910.

?  Formic acid accumulates within the optic nerve, which results in classic visual symptoms of flashes of light and blurring. Subsequently, this may progress to scotomas and scintillations.

?  Vision loss is thought to be caused by interruption of mitochondrial function in the optic nerve, resulting in hyperemia, edema, and optic nerve atrophy. Optic nerve demyelination has also been reported to be due to formic acid destruction of myelin.

?  Patients initially may present with diminished visual acuity, which can progress to scotomata and scintillations.

?  The frank blindness that develops sometimes responds to immediate therapy; however, complete loss of vision is a common sequela.

Physical: Physical examination helps to rule out other causes of altered mental status and visual dysfunction, the 2 most common presenting signs of methanol intoxication.

•  General physical examination

?  During the initial phase, individuals may experience effects similar to inebriation with alcohol and thus do not seek medical attention. As symptoms develop, most signs are related to metabolic acidosis manifested as tachycardia, tachypnea, hypertension, and altered mental status.

?  Pulmonary edema and acute respiratory distress may ensue, requiring intubation.

?  With large ingestions, depressed cardiac contractility heralds circulatory collapse and leads to signs of heart failure, cardiac arrhythmias, or both.

•  Neurologic examination

?  In addition to the progression from drowsiness to stupor to coma, ocular findings are prominent during a careful neurologic examination.

?  Visual symptoms necessitate a thorough examination of the fundi.

?  Optic disc hyperemia occurs early in the course of the methanol intoxication.

?  Pupillary response to light is compromised and, subsequently, is lost. Little to no retinal damage is observed.

Causes: Methanol intoxication occurs in several discrete populations.

•  Accidental overdose can be seen in children. Methanol is found commonly in antifreeze, perfumes, paint solvents, photocopying fluid, and windshield washing fluid, all of which are readily available.

•  Alcoholic persons commonly consume methanol as a substitute for ethanol. The excessive consumption of methanol then leads to intoxication.

•  In many parts of the developing world, methanol is often a component of "bootlegged alcohol," which is made in rural regions. Because of its low cost, it is often consumed by those in lower socioeconomic classes.

•  In the industrial setting, inhalation of methanol fumes is a risk. It is used in the production of formaldehyde and shellac processing. In addition, it is used as an extractant in chemical processes and as a denaturant in ethanol (Rosenstock, 1994).

•  Suicide attempts using methanol are uncommon (Jacobsen, 1997).