Eating inferior wine often leads to blindness and even death because it contains methanol commonly known as industrial alcohol. Methanol is highly toxic to human body, because it will be oxidized into formaldehyde and formic acid (formic acid) which are more toxic than methanol in human metabolism.

Methanol is very toxic, which has the greatest influence on the nervous system and blood system of human body. Toxic reactions can occur after ingestion through digestive tract, respiratory tract or skin, and methanol vapor can damage human respiratory mucosa and vision. Symptoms of acute poisoning include: headache, nausea, stomachache, fatigue, blurred vision and even blindness, and then dyspnea, eventually leading to respiratory center paralysis and death. Chronic toxic reactions are dizziness, lethargy, headache, tinnitus, decreased vision and digestive system disorder. If the intake of methanol exceeds 4g, poisoning reaction will occur; If a small cup of methanol exceeds 10g by mistake, it will lead to blindness and death. The lethal dose is more than 30 ml, and methanol is not easy to be discharged in the body, but will accumulate. Formaldehyde and formic acid generated by oxidation in the body are also toxic. In the methanol production plant, the relevant departments of our country stipulate that the allowable concentration of methanol in the air is 50mg/m3, and gas masks must be worn when working in the field with methanol gas. The wastewater can only be discharged after treatment, and the allowable content is less than 200 mg/L. ..