Under normal circumstances, it is a colorless toxic gas with pungent smell and very strong hygroscopicity. White smoke is produced when it meets air, which is easily soluble in water and can be infinitely mixed with water to form hydrofluoric acid. Hydrogen fluoride is a colorless gas with a pungent smell. Hydrogen fluoride and its aqueous solution are toxic and easy to deform bones and teeth. Hydrofluoric acid can be absorbed by mucosa, respiratory tract and gastrointestinal tract through skin. Poisoning should be treated immediately and sent to a doctor.
It is a highly corrosive reagent and highly toxic. It is a colorless gas, and in the air, as long as it exceeds 3ppm, it will produce an irritating taste. Hydrofluoric acid is an aqueous solution of hydrogen fluoride, which can be absorbed through skin mucosa, respiratory tract and gastrointestinal tract. If you accidentally contact hydrofluoric acid, you should immediately rinse it with plenty of water for 20 to 30 minutes, and then smear it with calcium gluconate ointment or liquid medicine; If you accidentally drink it by mistake, you should immediately drink a lot of high-calcium milk and then send it to the hospital for emergency treatment.
Skin contact: Take off contaminated clothes immediately and rinse with plenty of running water for at least 15 minutes. See a doctor.
Eye contact: lift the eyelid immediately and rinse it thoroughly with plenty of flowing water or normal saline for at least 15 minutes. See a doctor.
Health hazard: It is strongly irritating and corrosive to respiratory mucosa and skin.
1, acute toxicity: LC50 (lethal concentration): 1276ppm (inhaled by rats,1h); 342ppm (inhaled by mice, 1h)
2. Stimulation: Percutaneous in rats: 50%(3min), severe stimulation.
Human eye: 50mg 6 1. 1ppm, severely stimulated.
3. Subacute and chronic toxicity: rabbits inhaled 33~4 1mg/m3, 40~5 1. 1PPM with an average of 20mg/m3. After 1~5.5 months, 24.44PPM can cause mucosal irritation, emaciation, dyspnea, hemoglobin reduction and reticulation.
4. Mutagenicity: DNA damage: Drosophila inhalation 1.3PPM(6 weeks).
Sex chromosome deletion and non-segregation: Drosophila melanogaster inhaled 2.9PPM.
Cytogenetic analysis: Rats inhaled 1mg/m3 every day for * * * 24 days (intermittent).
5. The lowest toxic concentration (TCLO) of rats is 4980μ g/m3 (pregnancy 1~22d), which leads to fetal death.
Case example
According to media reports in Taiwan Province Province, a 42-year-old man surnamed Chen in Taichung City recently engaged in resource recycling, and his left index finger, middle finger and ring finger were splashed with unknown liquid, causing unbearable pain. When he went to the hospital, he was diagnosed as being burned by hydrofluoric acid, commonly known as "osteolytic water". After applying antidote, debridement and skin grafting, the third finger of the left hand was preserved. Hydrofluoric acid liquid is usually used for rust removal or air conditioning cleaning in industry. Most injuries occurred in the panel industry in the laboratory or semiconductor industry.
Professor Zheng Zhihong, a natural science teacher, said that the skin burned by strong acid and alkali has different manifestations. When it meets sulfuric acid, it will turn black, when it meets hydrochloric acid, it will swell and blister, and when it meets sodium hydroxide, it will sag. Hydrofluoric acid is the most terrible. At the initial stage, the skin has no symptoms, only tingling. In fact, it erodes bones, which is the so-called "bone melting water". It is suggested that if you are burned by strong acid and alkali, wash it immediately and ask others to call 165433.
Cai Bingheng, a plastic surgeon at Taichung Clarification Hospital, suggested that if someone is scalded by unknown liquid, they should use towels and toilet paper first. Absorb the residual liquid on their skin, then rinse it with water for more than 30 minutes to dilute it, and then send it to the hospital for emergency treatment, so that doctors can judge what kind of liquid it is and do the most appropriate treatment.
The man surnamed Chen said that when he flipped the plastic container a few days ago, his left finger was splashed with unknown liquid. At that time, he felt a sharp pain like a cone bone and immediately went to the hospital for emergency treatment.
After Chen arrived at the hospital, his left index finger, middle finger and ring finger turned pale. The doctor judged that it was not caused by ordinary acid-base solution. After blood test, it was found that he was burned by chemical liquid. After emergency consultation in plastic surgery, he was diagnosed as hydrofluoric acid burn and given an antidote. He also underwent debridement and skin grafting to save his fingers.
Cai Bingheng said that hydrofluoric acid is usually used to remove rust or wash air conditioners in industry. Its most special feature is that it cannot be stored in a glass container, but must be stored in a plastic container. It is very corrosive, which not only damages the skin, but also corrodes bones and muscles very easily. Chemical components can even enter the human body with blood, which is life-threatening. Because hydrofluoric acid burns have no symptoms in the early stage, they are easily mistaken for burns and miss the opportunity for treatment. Some patients will eventually have their limbs amputated.
Hydrofluoric acid is very corrosive and can dissolve many glasses that other acids can't, so it must be kept in plastic containers.
Hydrofluoric acid is colorless but irritating, and corrosive as "bone water" in martial arts novels. Usually used for industrial rust removal or cleaning, such as semiconductor, motherboard industry, petrochemical industry, nuclear power substances and refrigerants, and laboratories above universities. We must pay special attention to its high risk. Some industrial strong detergents or rust removers also contain hydrofluoric acid, so we should be especially careful when using them to avoid injury.
Hydrogen fluoride cylinders are stored in a cool and ventilated warehouse with indoor temperature not exceeding 40℃. No fireworks, stay away from kindling and heat sources, and prevent direct sunlight and rain; Gas cylinders shall be equipped with safety protection caps, stored upright and fixed. The warehouse is equipped with leakage detection and alarm devices, as well as leakage prevention and emergency treatment devices (such as automatic spraying devices, etc.). ) for regular inspection and record.
In the presence of oxygen, copper is quickly corroded by HF, but it will not react without oxidant. Some alloys, such as Monel, have good corrosion resistance to HF, but stainless steel has poor corrosion resistance, and carbon steel has enough corrosion resistance at a low temperature.
Hydrogen fluoride is nonflammable, but it is dangerous when mixed with some substances (such as sodium, calcium oxide, methyl nitrate, sodium chlorate, etc.). ).
In electronic industry, anhydrous hydrogen fluoride is used as raw material for electrolytic synthesis of nitrogen trifluoride and etchant in semiconductor manufacturing. In addition, hydrogen fluoride is also used in industrial production of hydrofluoric acid, inorganic fluoride, uranium processing, metal processing and etching agent in glass industry. The main detection principle is electrochemistry.
The maximum allowable concentration in GB3095- 1996 standard atmosphere is 0.02 mg/m3, 0.02444 ppm, and the daily average value is 0.007mg/m3；; . 0.00855PPM
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