Why is methanol toxic

Stay upwind. Liquid agent is lighter than water. The by-products of methanol metabolism cause an accumulation of acid in the blood metabolic acidosis , blindness, and death.

Initial adverse health effects due to methanol poisoning include drowsiness, a reduced level of consciousness CNS depression , confusion, headache, dizziness, and the inability to coordinate muscle movement ataxia. Other adverse health effects may include nausea, vomiting emesis , and heart and respiratory cardiopulmonary failure. Early on after methanol exposure, there may be a relative absence of adverse health effects. This does not imply insignificant toxicity. Methanol toxicity worsens as the degree of metabolic acidosis increases, and thus, becomes more severe as the time between exposure and treatment increases.

Gastrointestinal: Nausea, vomiting, lack of an appetite anorexia , severe abdominal pain, gastrointestinal bleeding hemorrhage , diarrhea, liver function abnormalities, and inflammation of the pancreas pancreatitis. Ophthalmologic: visual disturbances, blurred vision, sensitivity to light photophobia , visual hallucinations misty vision, skin over the eyes, snowstorm, dancing spots, flashes , partial to total loss of vision, and rarely eye pain.

Visual examination may reveal abnormal findings. Fixed dilated pupils are a sign of severe exposure to methanol. Other: Electrolyte imbalances. Kidney failure, blood in the urine hematuria , and muscle death at the cellular level rhabdomyolysis have been reported in severe poisonings. Fatal cases often present with fast heart rate tachycardia or slow heart rate bradycardia and an increased rate of respiration. Low blood pressure hypotension and respiratory arrest occur when death is imminent.

See Ingestion Exposure. Care should be taken during decontamination, because absorbed agent can be released from clothing and skin as a gas. Your Incident Commander will provide you with decontaminants specific for the agent released or the agent believed to have been released.

The warm zone should include two decontamination corridors. One decontamination corridor is used to enter the warm zone and the other for exiting the warm zone into the cold zone. The decontamination zone for exiting should be upwind and uphill from the zone used to enter. Decontamination area workers should wear appropriate PPE.

See the PPE section of this card for detailed information. A solution of detergent and water which should have a pH value of at least 8 but should not exceed a pH value of Soft brushes should be available to remove contamination from the PPE. Labeled, durable 6-mil polyethylene bags should be available for disposal of contaminated PPE. Always move in a downward motion from head to toe. Make sure to get into all areas, especially folds in the clothing.

Wash and rinse using cold or warm water until the contaminant is thoroughly removed. Place all PPE in labeled durable 6-mil polyethylene bags. Remove all clothing at least down to their undergarments and place the clothing in a labeled durable 6-mil polyethylene bag.

First Aid. The goal of treatment is to either prevent the conversion of methanol to toxic metabolites or to rapidly remove the toxic metabolites and correct metabolic and fluid abnormalities. Immediately wash eyes with large amounts of tepid water for at least 15 minutes.

Seek medical attention immediately. Do not induce vomiting emesis. Evaluate respiratory function and pulse. If shortness of breath occurs or breathing is difficult dyspnea , administer oxygen. Assist ventilation as required. Always use a barrier or bag-valve-mask device. If breathing has ceased apnea , provide artificial respiration. Long-Term Implications.

Fomepizole is preferred as its efficacy and safety have been demonstrated, and its therapeutic dose is more easily maintained. Folinic acid leucovorin should also be administered intravenously to increase the rate at which formate is metabolized into less toxic chemicals. DELAYED EFFECTS OF EXPOSURE : The most common permanent adverse health effects following severe methanol poisoning are damage to or death of the nerve leading from the eye to the brain optic neuropathy or atrophy , resulting in blindness; disease caused by damage to a particular region of the brain, resulting in difficulty walking and moving properly Parkinsonism ; damage to the brain caused by exposure to toxins, resulting in abnormal thought encephalopathy ; and damage to the peripheral nervous system.

Chronic or repeated exposure to methanol is suspected to be a developmental toxicity risk. It is unknown whether chronic or repeated exposure to methanol is a reproductive toxicity risk. Methanol may cause birth defects of the central nervous system in humans. Chronic poisoning from repeated exposure to methanol vapor may produce inflammation of the eye conjunctivitis , recurrent headaches, giddiness, insomnia, stomach disturbances, and visual failure.

The most noted health consequences of longer-term exposure to lower levels of methanol are a broad range of effects on the eye. Inflammatory changes and irritation of the skin dermatitis , occurs with chronic or repeated exposure to methanol. On-Site Fatalities. Coordinate responsibilities and prepare to enter the scene as part of the evaluation team along with the FBI HazMat Technician, local law enforcement evidence technician, and other relevant personnel.

Begin tracking remains using waterproof tags. If initiated early, treatment of methanol is highly effective, but it is often hampered by late diagnosis and lack of diagnostics and therapeutics.

Methanol is a widely available chemical used for many purposes: as a solvent in inks and dyes, in chemical synthesis and as a transportation fuel.

Outbreaks of methanol poisoning often occur when methanol is added to alcoholic drinks. People do this to make money. You can buy methanol in thousands of litres for industrial purposes. The methanol is then added to normal drinking alcohol ethanol , diluting it and allowing it be sold on a larger profit. In the absence of ethanol, it takes about hours to produce enough formate for symptoms of poisoning to appear.

Many are in a severe condition, in need of intensive care and dialysis. As patients with methanol poisoning often need intensive medical care, outbreaks can rapidly overwhelm medical facilities, and ministry of health MoH staff generally do not have the capacity and knowledge to diagnose and treat them properly.

Outbreaks frequently occur all over the world with hundreds, possibly thousands, dying every year from methanol poisoning. A large anion gap not accounted for by lactate may be a clue to a potential toxic alcohol ingestion. High beta-hydroxybutyrate levels may suggest alcoholic ketoacidosis as the cause or contributor to the anion gap. Treatment Top.

Decontamination : There are no known methods of decontamination. Activated charcoal does not adsorb methanol but may be worthwhile if coingestion of other drugs or toxins is suspected. If ingestion of a large volume occurred within 20 to 30 minutes of presentation, aspiration of gastric contents may be performed.

Antidotes and specific therapies : By competitively inhibiting alcohol dehydrogenase and methanol metabolism, the amount of formaldehyde and formic acid produced can be limited. Note that both ethanol and fomepizole are reasonable first-line agents for toxic alcohol poisoning. Despite the higher direct cost of fomepizole, we suggest its use due to ease of administration and likely less need for monitoring.

Evidence 1 Weak recommendation benefits likely outweigh downsides, but the balance is close or uncertain; an alternative course of action may be better for some patients. Low Quality of Evidence low confidence that we know true effects of the intervention. Quality of Evidence lowered due to lack of experimental head-to-head comparisons and only indirect data from observational studies.

For discussion on ethanol vs fomepizole in toxic methanol poisoning, see Appendix 1 at the end of the chapter. A systematic review of ethanol and fomepizole use in toxic alcohol ingestions.

Emerg Med Int. Epub Jan The loading dose will need to be adjusted if the patient has coingested ethanol and the maintenance dose doubled during dialysis. The maintenance rates will need to be doubled if the patient is on dialysis. Sometimes ethanol is added to the dialysate. Since fomepizole is dialyzed, the dosing frequency is increased to every 4 hours during dialysis. Accelerated elimination : Hemodialysis is very efficient at removing methanol and formate.