Health hazards: acute toxicity is manifested as anesthesia; Long-term exposure can lead to vinyl chloride disease. Acute poisoning: when the patient is slightly poisoned, he will feel dizzy, chest tightness, lethargy, gait staggering, etc. Severe poisoning can lead to coma, convulsions and even death. Skin contact with vinyl chloride liquid can cause erythema, edema or necrosis. Chronic poisoning: manifested as neurasthenia syndrome, hepatomegaly, abnormal liver function, digestive dysfunction, Raynaud's syndrome and osteolysis of limbs. Dry skin, chapped skin, desquamation, eczema, etc. This product is a carcinogen, which can cause hepatic angiosarcoma.
Environmental hazard: Vinyl chloride can participate in photochemical smog reaction in the environment. 2. Impact on the environment:
I. Health hazards
Invasion route: inhalation.
Health hazards: acute toxicity is manifested as anesthesia; Long-term exposure can lead to vinyl chloride disease.
Acute poisoning: when the patient is slightly poisoned, he will feel dizzy, chest tightness, lethargy, gait staggering, etc. Severe poisoning can lead to coma, convulsions and even death. Skin contact with vinyl chloride liquid can cause erythema, edema or necrosis.
Chronic poisoning: manifested as neurasthenia syndrome, hepatomegaly, abnormal liver function, digestive dysfunction, Raynaud's syndrome and osteolysis of limbs. Dry skin, chapped skin, desquamation, eczema, etc. This product is a carcinogen, which can cause hepatic angiosarcoma.
Vinyl chloride is an irritant, which will irritate eyes and skin when exposed to low concentration for a short time, and will cause frostbite due to rapid evaporation after contacting its liquid. It has anesthetic effect on human body, can inhibit the central nervous system and cause symptoms similar to mild alcoholism. When inhaled above 0.5%, it can cause dizziness, headache, nausea, vomiting, anxiety and disorientation. When the contact concentration is 20% ~ 40%, it may cause acute poisoning.
Second, toxicological data and environmental behavior.
Toxicity: It is carcinogenic to animals and people, and it is hepatic angiosarcoma. High concentration can produce different degrees of anesthesia, mainly depending on the inhaled dose. Long-term small inhalation can cause chronic liver and kidney dysfunction. It is a carcinogen.
Acute toxicity: LD50500mg/kg (taken orally by rats); Inhalation10.4g/m3× 5min without feeling; Inhalation 15.6g/m3, slightly uncomfortable; Inhalation of 3 1.2 ~ 4 1.6g/m3 causes dizziness, shyness and vomiting.
Subacute and chronic toxicity: Rats inhaled 30-40mg/m3 of steam for 4 hours every day for 5 months. After 20 days, ECG changes, bradycardia and arrhythmia were observed. Four and a half months later, there was atrioventricular conduction disorder. 7900mg/m3, 4 hours/day, 5 days/week, 12 months, with brain, liver, lung, kidney disease and tumor.
Mutagenicity: Microbial mutagenicity: Salmonella typhimurium 2000ppm(48 hours). Microsomal mutation: Salmonella typhimurium 1pph. Cytogenetic analysis: human Hela cells 10 mmol/L.
Reproductive toxicity: The lowest toxic concentration of inhalation in rats (TCL 0): 500 ppm (7 hours), pregnant for 6- 15 days, causing embryo toxicity. The lowest toxic concentration (TCL 0) in mice was 500 ppm (7 hours), and the mice were pregnant for 6- 15 days, which caused embryo toxicity and abnormal musculoskeletal development.
Carcinogenicity: IARC Carcinogenicity Review: Human Carcinogens. Inhale 500ppm×4 years gap; Rats inhaled 6000ppm×4 hours/day (pregnancy 12 ~ 18 days) tumor and cancer.
Pollution source: Vinyl chloride is an important raw material in the plastic industry, which is mainly used as a monomer for manufacturing PVC, and can also be made into a polymer with vinyl acetate, butadiene, acrylonitrile and acrylate. To make synthetic fibers. It is also used as an intermediate or solvent for manufacturing chemicals and producing vinylidene chloride, plastics and resins. It is also used as a refrigerant in refrigeration.
Metabolic degradation: A small part of vinyl chloride entering animals is metabolized into a substance called S-(α- chloroethyl)-cysteine, which has mutagenic activity but is very unstable. Due to hydrolysis, it can become S-(α- hydroxyethyl)-cysteine, which was detected in rat urine, and most of vinyl chloride was discharged in its original form. Vinyl chloride is a synthetic compound. As a hydrocarbon, it can participate in photochemical smog reaction in the environment. Compared with similar hydrocarbon molecules, the reactivity of vinyl chloride is moderate. The oxidation products of vinyl chloride in the atmosphere include formaldehyde, formic acid and hydrogen chloride.
Residue and accumulation: PVC-based polymer materials commonly used can emit volatile components at room temperature 18-22℃. In hot and dry climate, the content of toxic substances (including vinyl chloride) will increase. Dynamic observation shows that PVC-based floor paint will continue to discharge its synthetic raw materials (including vinyl chloride) into the environment after 5-6 months. Products based on PVC are widely used as packaging materials or containers in food industry. In the process of commercial sales and food preservation, vinyl chloride may escape into food at any time. For example, in a bottle made of PVC, about 0.002-0.08mg/kg of vinyl chloride was detected from several drinks after 40 days. It must be pointed out that the diffusion of vinyl chloride is related to the storage time of the instrument. After beer was filled in PVC bottles for 6 years, 2mg/kg of vinyl chloride could be detected in beer. During the period from 1 to 12 months after filling water, it was found that the amount of vinyl chloride monomer transferred into water was about 0.0 1-0.2 mg/L, while in ethanol it was 0.365 mg/L.. It was found that the amounts of vinyl chloride entering peanut oil, vinegar and brandy from PVC containers were 0.3-33mg/L, 8.4mg/L and 65,438 0.6 mg/L respectively. In the study of understanding that vinyl chloride monomer in PVC film enters ethanol, after 7 ~ 30 days of observation, no vinyl chloride monomer enters ethanol.
Migration and transformation: it is the main source of vinyl chloride precipitation and entering the environment in the process of preparation, production and processing of polyvinyl chloride and the production of various polymers with polyvinyl chloride as raw material. Because PVC-based polymer materials contain vinyl chloride monomers that are not involved in polymerization, they will escape into the environment during exposure. Animals were gavaged with soybean oil containing 300 mg/kg vinyl chloride. After 4 hours, 92% of vinyl chloride was excreted through various channels. It can be seen that the low dose of vinyl chloride ingested with water and food stays in the body for a short time, so most of vinyl chloride cannot be converted into metabolites. However, under the production conditions, people who inhale high concentration of vinyl chloride air for a long time will accumulate a lot of vinyl chloride in their blood and form metabolites, which will cause serious harm to human body. This accumulation and metabolism in the blood takes longer and the consequences are more serious.
Hazard characteristics: flammable, and can form explosive mixture when mixed with air. Danger of burning and explosion in case of heat source and open flame. Aggressive polymerization occurs when burning or without inhibitors. Its vapor is heavier than air, and it can spread to a considerable distance at a lower place, which will lead to tempering when it meets an open flame.
Combustion (decomposition) products: carbon monoxide, carbon dioxide, hydrogen chloride.
3. The field emergency monitoring method:
Gas detection tube method; Portable gas chromatograph; Direct water sampling gas chromatography
Gas rapid measuring tube (produced by Beijing Labor Insurance Institute and Doelger Company of Germany)
4. Laboratory monitoring methods: source categories of monitoring methods
Gas chromatography HJ/T34- 1999 Waste gas from stationary pollution sources
Zhang et al., chief editor of gas chromatography water quality analysis.
Handbook of gas chromatography for testing, analysis and evaluation of solid waste.
Chromatography/mass spectrometry EPA524.2 American water quality
5. Environmental standard: The maximum allowable concentration of harmful substances in the air of China (TJ36-79) workshop is 30 mg/m3.
China (GB 16297- 1996) Comprehensive Emission Standard for Air Pollutants ① Maximum allowable emission concentration (mg/m3).
36 (Table 2); 65 (Table 1)
② Maximum allowable discharge rate (kg/hour)
Secondary 0.77 ~ 16 (Table 2); 0.9 1 ~ 190 (table 1)
Grade iii 1.2 ~ 25 (table 2); 1.4 ~ 29 (table 1)
③ unorganized emission monitoring concentration limit (mg/m3)
0.040 (Table 2); 0.050 (table 1)
China (GHZB 1- 1999) has a surface water environmental quality standard (Class I, II and III waters) of 0.002 mg/L.
The maximum allowable concentration of harmful substances in drinking water sources in China (to be promulgated soon) is 0.005 mg/L.
The olfactory threshold concentration in the air is 10. 1 ~ 20.3 ppm.
6. Emergency treatment and disposal methods:
First, the emergency treatment of leakage
Quickly evacuate people in the leaked and polluted area to the windward, isolate them, and strictly restrict access. Cut off the fire. It is recommended that emergency personnel wear self-contained positive pressure breathing apparatus and fire protection clothing. Cut off the leakage source as much as possible. Cover the sewer and other places near the leakage point with industrial covering or adsorption/absorbent to prevent gas from entering. Reasonable ventilation and accelerated diffusion. Spray water is diluted and dissolved. Build a dike or dig a pit to contain a large amount of wastewater. If possible, send residual gas or leaked gas to the water washing tower or fume hood with exhaust fan. Leaked containers should be properly treated, repaired and inspected before use.
Waste disposal method: incineration. Waste and other fuels are mixed and burned, and the combustion should be sufficient to prevent phosgene production. Hydrogen halide discharged from the incinerator is removed by an acid scrubber.
Second, the protective measures
Respiratory system protection: Wear a filter gas mask (half mask) when the concentration in the air exceeds the standard. Air respirator is recommended for emergency rescue or evacuation.
Eye protection: Wear chemical safety glasses.
Physical protection: wear anti-static work clothes.
Hand protection: Wear chemical resistant gloves.
Others: Smoking is strictly prohibited in the workplace. Carry out pre-job and regular physical examination. Work in storage tanks, confined spaces or other high concentration areas must be supervised.
Third, first aid measures.
Skin contact: Take off the contaminated clothes immediately and rinse the skin thoroughly with soapy water and clean water. See a doctor.
Eye contact: Lift eyelids and rinse with running water or normal saline.
Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor.
Fire extinguishing method: cut off the gas source. If the gas source cannot be cut off immediately, it is not allowed to extinguish the burning gas. Spray water to cool the container, and if possible, move the container from the fire to an open place. Extinguishing agent: water mist, foam and carbon dioxide.