RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
1. Physical and chemical constants of substances
National standard number: CAS:7439-92-1
Chinese name: Lead
English name :Lead; Lead flake
Alias: None
Molecular formula: Pb Molecular weight :207.2
Melting point: 327° C
Density: Relative density (water =1)11.34(
Vapor pressure: 970 ° C
Solubility: Insoluble in water, soluble in nitric acid, hot concentrated sulfuric acid, lye, insoluble in dilute hydrochloric acid Stability: stable
Appearance and properties: gray and soft powder, shiny cutting surface, weak ductility, strong malleability
Hazard marks:
Uses: Mainly used for cable, battery, lead smelting, waste copper smelting, printing, soldering and so on
RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
2. Impact on the environment
1. Health hazards
Way of invasion: inhalation, ingestion.
Health hazard: Damage to hematopoietic, nervous, digestive system and kidney. Occupational poisoning is mainly chronic. The main manifestations of nervous system are neurasthenic syndrome, peripheral neuropathy (motor function is more obvious), and lead poisoning encephalopathy in severe cases. 4. The digestive system presents lead line of gums, loss of appetite, aversion, bloating, diarrhea or constipation. Abdominal cramps are seen in moderate and severe cases. Hematopoietic system damage appeared porphyrin metabolism disorders, anemia and so on. Short-term exposure to large doses can occur acute or subacute lead poisoning, similar to severe chronic lead poisoning.
Lead is inhaled in the form of inorganic substances or dust, or enters the body through the digestive tract through water or food. It accumulates in “reservoirs” in the bone marrow, liver, kidney, spleen and brain, and then slowly releases into the blood, causing chronic poisoning (acute poisoning is less common). Lead is toxic to the whole body, but especially to the nervous system, blood and cardiovascular systems. Alkyl lead compounds are flammable liquids, neurotoxic, and highly toxic. Acute poisoning can cause excitement, muscle tremors, spasms and quadriplegia
Toxicological data and environmental behavior
Acute toxicity: LD5070mg/kg(rat transvenous)Subacute toxicity: 10ug/m3, rats exposed to 30 to 40 days, red blood cell bilinogen synthase (ALAD) activity decreased by 80% to 90%6, blood lead concentration up to 150 to 200 ug/100ml, there are obvious symptoms of poisoning. At 10ug/m3, after 3 to 12 months of inhalation, the macrophages eluted from the lungs were reduced by 60%, and a variety of toxic symptoms appeared. 0.01mg/m3, human occupational exposure, urinary inflammation, blood pressure changes, death, fetal death in women.
RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
Chronic toxicity: Prolonged exposure to lead and its compounds can cause palpitations, lizard irritation, and erythrocythemia. When the lead impinges on the nervous system, insomnia, dreaminess, memory loss, fatigue, progress to mania, blindness, confusion, coma, and finally death due to cerebrovascular hypoxia.
Carcinogenic: Animal studies of inorganic compounds of lead suggest that they may cause cancer. It has also been documented that lead is a chronic and accumulative poison with varying individual sensitivities and is a potential urogenic carcinogen in humans.
Teratogenicity: Insufficient animal studies have been conducted to provide evidence of teratogenic effects of lead and its compounds.
Mutagenicity: In mice fed a diet containing 1% lead acetate, leukocyte cultures showed an increase in the number of chromosome fence-fracture type aberrations, which involve a single chromosome and indicate damage to DNA replication.
Metabolism and degradation: Inorganic lead and its compounds in the environment are very stable and not easy to metabolize and degrade. The toxicity of lead to the human body is cumulative, and 25% of the lead inhaled by the human body is deposited in the lungs, and some of it enters the blood through the dissolution of water. If a person’s continuous exposure to the air contains 1ug/m3 of lead, the level of lead in human blood is 1 to 2ug/100 mL of blood. About 10% of the lead ingested from food and drink is absorbed. For a daily intake of 10ug of lead from food, the blood level of lead is 6-18ug /100ml of blood. A small fraction of these lead compounds can be excreted through the digestive system, mainly in the urine (about 76%) and the intestines (about 16%), with the rest being excreted as the end product of metabolism by various less well known means, such as sweating, peeling and hair removal Exit the body.
Residue and accumulation: Lead is a cumulative poison that humans ingest through the food chain, but also from polluted air. Lead levels in the lungs of Americans are higher than in Africa, the Near East, and the Far East, because lead pollution in the atmosphere is higher in the United States than in those regionsCaused by heavy lead. Human autopsy results show that 70 to 90 percent of the lead that enters the human body ends up as lead phosphate (PbHP04) and attaches to bone tissue. The lead content in the bones of modern Americans is 100 times higher than that of ancient people. The amount of lead in this part increases gradually throughout life, and after it accumulates in the soft tissues of the human body, including the blood, to a certain extent (early adulthood), it hardly changes, and the excess is excreted on its own (as mentioned above), showing a significant turnover rate. Fish are highly concentrated in lead.
RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
Migration and transformation: According to the National Research Council of Ottawa, Canada, in 1978, a study on the migration of lead in the world’s environment reported that the average concentration of lead in seawater around the world is 0.03ug/L, and 0.5ug/L in fresh water. The mean atmospheric lead concentration in rural areas around the world0.1μg/m3, the concentration of lead in urban atmosphere ranges from 1 to 10ug/m3. The average background value of lead in soils and rocks around the world is 13mg/kg. The environmental outcome of lead in the world’s soils is 150,000 tons per year from air to soil, 250,000 tons from air to sea, and 416,000 tons from soil to sea. The annual transfer from seawater to sediment amounts to 400,000-600,000 tons. Lead in water, soil and air is absorbed by organisms and transferred to organisms, resulting in the average range of lead in various plant foods around the world0.1~1mg/kg(dry weight), the average lead content in food products is 2.5mg/kg, the average lead content in fish is 0.2~0.6mg/kg, and the lead content in some crustaceans and mollusks in coastal polluted areas is even more than 3000mg/kg.
Industrial pollution of lead comes from production wastewater and waste such as mining, smelting, rubber production, dyes, printing, ceramics, lead glass, solder, cables and lead pipes. In addition, tetraethyl lead in automobile exhaust is a highly toxic substance. When water bodies are contaminated with lead (Pb0.30.5mg/L), obviously inhibit the self-purification of water, 2~4mg/L, the water is turbidified.
Dangerous characteristics: The powder will cause combustion and explosion when exposed to heat, open fire or contact with oxidants.
Combustion (decomposition) product: lead oxide.
3. On-site emergency monitoring methodsDetermination of Harmful Substances in Air by colorimetric method in Tidi paper, edited by Hang Shiping
Tachymeter method; Spectrophotometry; Anodic stripping voltammetry, Emergency Monitoring and Treatment of sudden environmental Pollution Accidents, Wan Bentai, Ed
4. Laboratory monitoring methods
Monitoring methodsSources
CategoriesAtomic Absorption Method GB7475-87 Water quality
McSo-tetra-(p-sulfobenzene) porphyrin photometry WS/T126-1999 Workplace air
Hydride generation-atomic absorption method WS/T127-1999 Workplace air
Atomic absorption method GB/T15555.2-95 Solid waste leach solution
Graphite furnace atomic absorption method GB/T17141-1997 Soil
Flame atomic absorption method GB/T17140-1997 Soil
Flame atomic absorption Method GB/T15264-94 Air quality
Atomic absorption method CJ/T101-99 Municipal solid waste
Atomic absorption method “Solid Waste Test Analysis and Evaluation Manual” China Environmental Monitoring Station and other translations of solid waste
5. Environmental standards
China (TJ36-79) the maximum allowable concentration of hazardous substances in the air of workplace 0.03mg/m3[lead smoke]; 0.05mg/m3[lead dust]Maximum allowable concentration of hazardous substances in the atmosphere of residential areas in China (TJ36-79) 0.0007mg/m3(daily mean)
RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
China (GB3092-1996) Seasonal average ambient air quality standard: 1.50ug/m3Annual average: 1.00ug/m3
China (GB16297-1996) Comprehensive Emission Standard for Air Pollutants (Lead and its compounds)① Maximum allowable emission concentration (mg/m3) :
0.90(Table 1); 0.70(Table 2)
② Maximum allowable emission rate (kg/h) :
Level 2 0.005~0.39; Level 3 0.007~0.60(Table 1)
Level 2 0.004~0.33; Level 3 0.006~0.51(Table 2)
③ Unorganized emission monitoring concentration limit:
0.0060mg/m3(Table 2); 0.0075mg/m3(Table 1)
China (GB5749-85) Drinking water quality Standard 0.05mg/L
China (GHZB1-1999) Surface Water Environmental Quality Standard (mg/L) Class 1 0.01; Class 1 0.05; Class 1 0.05; Class IV 0.05; Class V 0.1
China (GB/T14848-93) Groundwater Quality Standard (mg/L) Class I 0.005; Class II 0.01; Class III 0.05; Class IV 0.1; Class V >0.1
China (GB3097-1997) Seawater Quality Standard (mg/L) Class 1 0.001; Class 1 0.005; 1 class 0.010; Class IV 0.050
China (GB5048-92) Water Quality Standard for farmland irrigation 0.1mg/L(water cropping, early cropping, vegetables)
China (GB11607-89) fishery water quality standard 0.05mg/L
China (GB8978-1996) Comprehensive sewage discharge standard 1.0mg/L
China (GB15618-1995) Soil Environmental Quality standard (mg/kg) -Class 35; Grade II 250~350; Grade III 500
China (GB5058.3-1996) Standard value of solid waste leaching toxicity identification 3mg/L1
China (GWKB3-2000) domestic waste incineration pollution control standard Incinerator air pollutant emission limit: 1.6mg/m3(measured mean)
China (GB8172-87) urban waste agricultural control standard 100mg/kg
RoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
6. Emergency treatment and disposal methods
First, emergency treatment of leakage
Cut off the fire source. Wear a gas mask and general fire protective clothing. Collect with a clean shovel in a dry, clean container with a lid. Cure with cement, asphalt or appropriate thermoplastic material before disposing. If a large number of leaks, collect and recycle or dispose of harmlessly before disposing.
① For leaking PbCI4 and Pb(CIO4)2, all protective equipment such as gas masks should be worn. Mix with dry sand soil, pour in small batches into a large amount of water, and put the diluted sewage into the wastewater system.
2 Wear all protective equipment, including a gas mask, for leaking PbO, tetramethyl (B) base lead, and Pb304. Mix it with dry sand and dump it in an open area for burial; The polluted ground is washed with soap or detergent, and the diluted sewage is put into the waste water system.
③ For leaking PbF2, all protective equipment such as gas masks should be worn. Sprinkle soda ash on the leak; The contaminated ground is washed with water and the diluted sewage is put into the wastewater system.
④ For leaking Pb(BrO3)2, PbO2 and Pb(NO3)2, all protective equipment such as gas mask should be worn. The contaminated surface should be washed with water, and the diluted sewage should be put into the waste water system.
5 Scrub the spilled alkyl lead with an emulsion made of a non-combustible dispersant. If no dispersant can be absorbed by sand, pour to an open place and bury; The contaminated ground is washed with soap or detergent, and the diluted sewage is put into the waste water system.Treatment method: When the water body is polluted, it can be treated by neutralizing method, that is, adding lime milk to adjust the pH to 7.5, so that the lead precipitates in the form of lead hydroxide and transfers from the water to the sludge. With mechanical stirring can accelerate the clarification, the purification effect is 80%~96%, and the concentration of lead in the treated water is 0.37~0.40mg/L. And the sludge to do further harmless treatment. For lead-contaminated soil, amendments such as lime and phosphate fertilizer can be added to reduce the activity of lead in the soil and reduce the absorption of lead by crops.
Treatment method: When the water body is polluted, it can be treated by neutralization method, that is, adding lime milk to adjust the pH to 7.5, so that the lead precipitates in the form of lead hydroxide and transfers from the water to the sludge. With mechanical stirring can accelerate the clarification, the purification effect is 80%~96%, the concentration of lead in the treated water is 0.37-0.40mg/L. And the sludge to do further harmless treatment. For lead-contaminated soil, amendments such as lime and phosphate fertilizer can be added to reduce the activity of lead in the soil and reduce the absorption of lead by cropsRoHS2.0 limits the harm of heavy metals lead, cadmium, mercury and chromium and monitoring methods
二, protective measures
Respiratory protection: Workers should wear dust masks.
Eye protection: Safety masks can be used if necessary.
Protective clothing: Wear overalls.Hand protection: Wear protective gloves if necessary
.Other: Smoking, eating and drinking are prohibited at the work site. After work, shower and change clothes. Perform pre-employment and regular medical check-ups. Maintain good hygiene.
Third, first aid measure
sSkin contact: Take off contaminated clothing and rinse thoroughly with soapy water and running water
Eye contact: immediately open the upper and lower eyelids, rinse with running water or normal saline. Seek medical attention.
Inhalation: Quickly remove from scene to fresh air. Keep airway clear. Give oxygen when breathing is difficult. When breathing stops, give artificial respiration immediately. Seek medical attention.
Ingestion: Give enough warm water to induce vomiting and seek medical attention.
Fire extinguishing method: dry powder, sand.