Acute toxicity of dimethylformamide: LD50:400mg/kg(orally in rats); 5000mg/kg(rabbit transdermal). LC50:9400mg/m3, 2h(inhaled by mice).
Toxicity and emergency treatment of dimethylformamide
Inhalation of 30 ~ 60ppm, digestive tract symptoms, liver function can be abnormal, jaundice, increased urinogen, proteinuria;
People inhaling 10 to 20ppm(sometimes 30ppm) have headache, loss of appetite, nausea, and normal liver function and ecg.
Subacute and chronic toxicity: rats inhaled 2500mg/m3,6h/d, 5d, 80% death, liver and lung lesions;
After inhalation of 5.1 ~ 49mg/m3 for 3 years, neurasthenia syndrome, low blood pressure and liver function changes were observed.
Metabolism: N, N-dimethylformamide (DMF) is mainly metabolized in the liver after absorption through various ways, with rapid excretion. The main target organ is the liver, and the kidney also has certain damage. Demethylation is carried out mainly through mixed functional oxidase in liver microsomes, in which a methyl group is removed and the metabolites are methyl formamide and formamide, which metabolize rapidly. Formamide remains in the blood a little longer, and the Chemicalbook is then metabolized to formic acid and ammonia. Part of the dimethylformamide is excreted in the urine and in the expiratory form.
Health hazards: irritation to eyes, skin and respiratory tract. Steam can cause mild and moderate irritation of eyes and upper respiratory tract. Pollution of the skin can cause light and severe burns, wrinkling of the skin, whitening of the skin, accompanied by burning sensation, severe swelling of the skin, severe burning pain. Pollution eyes cause burning pain, tears, conjunctival congestion; Severe cases can cause corneal necrosis.
Gastrointestinal symptoms: patients often have loss of appetite, nausea, vomiting, abdominal discomfort and constipation, a few cases have middle and upper abdominal pain. Liver: when acute poisoning, liver damage is often more prominent, the patient has obvious fatigue, right upper abdomen distension pain, discomfort, jaundice, liver gradually swelling, tenderness, routine liver function examination shows abnormal, among which serum transaminase increase is more obvious. The disease is generally not serious, after treatment can be gradually relieved, the condition can be fully recovered in a few weeks. Severe acute poisoning: manifested as severe toxic liver disease, occupational poisoning is rare, exposure to high concentration, especially serious skin contamination, not thoroughly washed in time, should be vigilant for serious poisoning.
Treatment principle: leave the site, take off the contaminated clothes, immediately wash the skin with water when it is contaminated. No special antidote, mainly to protect the liver. Symptomatic treatment, such as hemorrhagic gastroenteritis. Adrenal glucocorticoids may be administered for severe poisoning. Preventive measures: the production process as Chemicalbook may be closed, strengthen local air suction and waste gas recovery. Use respirators properly during equipment maintenance. Contact with lye should be avoided to avoid the production of dimethylamine, another poison. Hazard classification (GB5044-85) : ⅲ (moderate hazard).