Methanol (CH3OH) is the simplest saturated monoalcohol with its CAS number of 67-56-1 or 170082-17-4, a molecular weight of 32.04, and a boiling point of 64.7°C. It is also called "wood alcohol" or "wood spirit" because it was first discovered in dry distilled wood. The lowest human oral poisoning dose is about 100 mg/kg body weight, and oral intake of 0.3 to 1 g/kg can be fatal. Used in the manufacture of formaldehyde and pesticides, etc., and as an extractant of organic matter and a denaturant of alcohol. The finished product is usually made by reacting carbon monoxide with hydrogen.
Security measures
Health hazards
Methanol is well known to the public and is toxic. Industrial alcohol contains about 4% methanol. If illegal molecules are used as edible alcohol to make fake alcohol, after drinking, methanol poisoning will occur. The lethal dose of methanol is about 70 milliliters. The toxicity of methanol has the greatest impact on the human nervous system and blood system. It can cause toxic reactions when ingested through the digestive tract, respiratory tract or skin. Methanol vapor can damage the respiratory mucosa and vision. In methanol production plants, the relevant Chinese authorities stipulate that the concentration of air methanol is limited to PC-stel=50mg/m3 and PC-TWA=25mg/m3. Gas masks must be worn when working on sites with methanol gas, and factory wastewater must be treated. For emissions, methanol with a content of less than 200mg/L is allowed.
　　 The poisoning mechanism of methanol is that methanol is metabolized by the human body to produce formaldehyde and formic acid (commonly known as formic acid), which then causes harm to the human body. The common symptoms are a feeling of drunk first, headache, nausea, vomiting, and blurred vision a few hours later. In severe cases, blindness or even death may occur. Causes of blindness: formic acid, a metabolite of methanol, accumulates in the eye and destroys the optic nerve cells. The cranial nerves will also be destroyed, resulting in permanent damage. After formic acid enters the blood, it will make the tissues more and more acidic, damage the kidneys and cause kidney failure. Toxicity: Low toxicity.
Methanol is low toxic to the human body, because methanol will be oxidized into formaldehyde and formic acid (formic acid), which are more toxic than methanol in human metabolism.
The initial symptoms of poisoning include rapid heartbeat, abdominal pain, vomiting (vomiting), diarrhea, loss of appetite, headache, dizziness, and general weakness. In severe cases, they may become confused, have rapid breathing and become exhausted. Blindness is the most typical symptom. After methanol enters the blood, it will increase the acidity of the tissues and cause acidosis, leading to kidney failure. The worst is death.
Hazard Prevention
Symptoms of poisoning
Physical hazards: it has anesthetic effect on the central nervous system; it has a special selective effect on the optic nerve and retina, causing disease; it can cause metabolic acidosis.
Acute poisoning: short-term inhalation of large amounts and mild upper-ocular respiratory tract irritation (or gastrointestinal irritation symptoms); headache, dizziness, fatigue, dizziness, drunkenness, hazy consciousness, delirium, and even coma after a period of incubation period . Optic nerve and retinopathy, there may be blurred vision, double vision, etc., severe cases of blindness. In metabolic acidosis, the carbon dioxide binding capacity decreases and the breathing speeds up.
Chronic effects: neurasthenia syndrome, autonomic dysfunction, mucous membrane irritation, vision loss, etc. Degreasing, dermatitis, etc. appear on the skin.
First aid measures
Skin contact: Take off contaminated clothing and wash skin thoroughly with soap and water.
Eye contact: Lift the eyelid, rinse with running water or normal saline, and seek medical attention.
Inhalation: quickly leave the scene to a place with fresh air. Keep the airway unobstructed. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately and seek medical attention.
Ingestion: Drink enough warm water, induce vomiting or gastric lavage with water or 1% sodium thiosulfate solution, and seek medical attention.
Leakage emergency response
Quickly evacuate personnel from the leaked contaminated area to a safe area, and isolate them, strictly restrict access and cut off the source of fire. It is recommended that emergency personnel wear self-contained positive pressure respirators, wear anti-static overalls, do not directly touch the leakage, and cut off the source of the leakage as much as possible. Prevent entry into restricted spaces such as sewers and flood drains. Small amount of leakage: Use sand or other non-combustible materials to absorb or absorb, or rinse with a lot of water, and put the washing water into the waste water system after being diluted. A large number of leaks: build a dike or dig a pit for storage, cover it with foam, and reduce vapor disasters. Use explosion-proof pump to transfer to tank truck or special collector, recycle or transport to waste disposal site for disposal.
Emergency overview
liquid. Highly flammable, its vapor mixed with air can form an explosive mixture. Toxic after swallowing. Toxic in contact with skin. Toxic by inhalation. Short-term exposure has the risk of serious damage to health.