PX in the end how much poison? PX project on the surrounding environment and residents threaten real number?

PX is a petrochemical industrial chain of intermediate goods, mainly used to produce PTA (purified terephthalic acid) and DMT (dimethyl terephthalate), is also preparing synthetic raw materials, textile and garments, plastic products One of raw materials and other intermediate consumer goods production upstream. Risk of accidents which may occur mainly fire and explosion accidents and chemical spills.
Dalian is not only a world-renowned tourist city, but also heavy chemical industry base. Dalian Fujia Dalian Development Zone is located in Newport Dagushan petrochemical industrial park, currently operates a single series known as the largest project of 700,000 tons PX aromatics. Allegedly, this project annual output of about 26 billion yuan, 20 billion yuan to pay taxes. It not only extends from the refinery to Dalian PX, the PTA, polyester chips and then petrochemical "golden chain", fill the Dalian Petrochemical only "oil head" no "of the tail" of the blank, but also effectively easing the domestic PX Imported products have long passive situation.
It is understood that this is not the PX project dike risks faced by the first threat. 16 July 2010 Japan-China oil pipeline exploded, it was lucky enough to brush with death; October 24 the same year, a second explosion in the same scene, which is lucky again to "escape" the. However, as long as the PX project exists, who do not know when and in what manner falling ......
Paraxylene toxicity does not mean there is no risk of the PX project
In fact, public PX project was not the first question. 2008, Xiamen PX project launched on public events questioning occurred, leading to the construction site of the project had changed. The results of Dalian this question is to allow people already discontinued production of PX chemical plant relocation.
PX in the end how much poison? PX project on the surrounding environment and threaten the residents really so big?
Nanjing Jinling PX project have been involved in pre-feasibility studies of Chinese Academy of Sciences, Professor of Chemistry and Chemical Engineering, Nanjing University doctoral tutor Chen Hongyuan told reporters, called PX chemical name or 1.4 xylene, paraxylene, low toxicity of the chemicals.
We all know that benzene is a highly toxic substance found in the paint, clothing and other daily necessities, is harmful to human health, the main chemical substances. Objectively speaking, paraxylene poisonous, but a lot less toxic than benzene and toluene.
Chen Hongyuan said aromatic hydrocarbon (or benzene homologues, the abbreviation of BTEX, including benzene, toluene, o-xylene, m-xylene, p-xylene) is the most toxic benzene series, the 1982 IARC (IARC ) benzene as a human carcinogen, 1993 WHO to determine not only the industrial toxicology of benzene, but also important environmental pollutants. US Environmental Protection Agency (US EPA) and the International Agency for Research on Cancer (IARC) as a carcinogen none of the xylene.
Participated in all Dalian Chemical Project EIA report Sinopec professor of Engineers, said Zhang, BTEX are highly toxic and carcinogenic, paraxylene product belongs to a branch of BTEX, also has some toxicity. However, there is something that is toxic classification, benzene, xylene, p-xylene are successively lower toxicity.
Head of the Department of Chemistry, Tsinghua University, National Taiwan 刘瑞雄 also believes paraxylene is relatively safe, physiological low toxicity in Taiwan does not belong to the toxicity of pipe products.
It is reported that the major environmental hazard paraxylene that if PX overturned in the transport, storage process, leaks, fires will cause accidental pollution incidents. Because PX eye and upper respiratory tract irritation, high concentrations have a narcotic effect on the central nervous system, inhalation of high concentrations of xylene and even acute poisoning.
Reporters learned that, at present there is a dispute on its toxicity internationally. Party point of view, PX poisonous, is a dangerous chemical, the fetus has a high rate of teratogenicity, and its vapor can form explosive mixtures with air. The other believes, PX low toxicity materials, lack of evidence of human carcinogenicity.
Chen Hongyuan say about PX environmental pollution on human health have a correct understanding of science. Human health affected by pollution in three ways: inhalation, oral and skin contact. Atmospheric pollution, the impact is primarily a first way, by inhalation of polluted air. But whether harm to human health, but also depends on the level of human exposure (the probability of exposure to toxic substances and dosage or concentration) and contact time.
See (Material Safety Data Sheet Material Safety Data Sheet) files reporter in the United States, Canada, Australia and many Asian countries have generally adopted MSDS, on paraxylene has this description: "Toxic low toxicity category pathways: Inhalation, eyes, skin, eating. "" eye and upper respiratory irritation, central nervous system have a narcotic effect at high concentrations. "
It is reported that, MSDS is the standard chemical production and sales of the world's most authoritative related to the chemical production or sale of business required by law of a comprehensive legal documents related to the chemical characteristics of the customers. Content is to provide physical and chemical parameters of chemicals, blasting performance, health hazards, safe storage, disposal leak sixteen content, emergency measures and related laws and regulations.
However, the senior director of Greenpeace pollution prevention projects 马天杰 think, paraxylene itself does not explain the low toxicity of PX project no risk.
"We can not stand alone to treat toxic xylene have to determine if it is a dangerous chemical, first of all it is irritating, while it is also a flammable. Although World Health Organization has not been particularly strong evidence to prove that it can cause cancer, but the PX and dangerous nature itself can not be equated to the entire environmental risk PX project because the project itself involves chemicals than PX, there are some other dangerous chemicals, they should all be considered in the construction environmental risks of the project in time. "马天杰 said.
It is reported that Dalian PX project in addition to producing paraxylene, the year also produced 100,000 tons o-xylene, 100,000 tons of liquefied gas, 600 million cubic meters of hydrogen gas, 100,000 tons 6 # solvent oil and 100,000 tons of 120 # solvent oil, 400,000 tons of toluene, a variety of products more than 200,000 tons pumping oil.
An unnamed chemical industry expert said that as a petrochemical enterprises, pollution is yes, no doubt. For example, in the production process will produce paraxylene and benzene, o-xylene, and its toxicity is much higher than that of para-xylene. Civil conflict for this project is normal.
However, the expert also stressed that we can not say because it is polluted, it can not be produced. Like chemical synthesis in the pharmaceutical industry, is the most polluted industries, its emissions are bulk chemicals (ammonia, urea, ethylene, etc.) of 15 to 20 times, but have to produce, it is indispensable that people pharmaceuticals.
"We wear the clothes, many of which are items used to paraxylene as raw material, our lives have been without it, the public do not panic it, and some people's reaction Dalian overdone." Liurui Xiong representation.
Experts pointed out that China's economic development, PX is the basic industry also needs to develop an important industry, the production is necessary. Are critical to ensure emissions control within the national emission standards, the pollutant discharge standards after entering the atmosphere, can meet the national environmental quality standards.
The international community did not have the location of the provisions of 100 km from the city
For PX project, a lot of people are worried about is that once a major spill would occur if a threat to life and health of the population, this fear is understandable. Previously, domestic PX device is out over the accident. In 2000, a domestic chemical fiber plant a 250,000 t / year PX project fire. Subsequent investigation, there is a lack of major design, there is no bottom cut-off valve, flame more than 100 meters, burned a dozen hours. The accident caused three major operations workers were killed, and the local atmospheric environment pollution. Xiamen PX project in opposition, there are experts that "foreign PX project must be located in 100 km away from the city where" point of view, is also found in the opposition Dalian PX project.
It is reported that Dalian PX project is located 21 kilometers away from Dalian city, 13 km away from the Dalian Economic and Technological Development Zone, 7.5 km from Xiaogushan residential area.
In the end there is no international regulations PX project must siting 100 km away from the city in it?
Chen Hongyuan academician said, "I have not heard of foreign regulations, this is just baseless assertion. Many foreign PX residential project close distance."
Reporters saw through the query data, a number of international projects from the city than in Dalian PX PX project even closer. For example, Houston PX device 1.2 kilometers from the city; Rotterdam PX device 8 km from the city center; Pusan ??PX device four kilometers from the city center; Exxon Mobil refinery in Singapore Jurong Island PX device 0.9 kilometers away from residential areas; Japan Yokohama NPRC refinery PX devices are only separated by a highway and residential areas.
In China, Tianjin Petrochemical PX device 5 km away from the Dagang Center; Qingdao Lidong Chemical Co. PX device is only 600 meters away from the residential area; Shanghai Jinshan Petrochemical PX device away from the nearest residential area about one kilometer away.
Liurui Xiong told reporters that no relevant international regulations, Taiwan can not require chemical plant was built in the city, to set up a separate petrochemical specialized area, away from residential areas within the range of 500 meters away.
"Dalian PX project is fully in line with domestic PX project site precedents and national EIA standard." Responsible for project environmental assessment of Dalian City, Central Research Institute, said publicly. Siting and protection from Dalian PX project construction projects through environmental impact assessment, after a rigorous scientific computing and experts repeatedly demonstrated determined.
In accordance with the provisions of the State Environmental Protection Department, the existence of the risk of contamination of the environment project site to determine the distance usually have three technical methods: safety distance, Health Protection and atmospheric environment protection distance.
Security from the main means of fire, explosion, leakage accidents at preventing and reducing the minimum safe distance of casualties, poisoning, destruction of property near the device and need;
Health protection, mainly refers to devices or equipment fugitive emission sources, also known as non-point source (15m above the chimney or exhaust emissions is organized, or called elevated point sources), the harmful effects of emissions of pollutants from plant or plant boundary to boundary minimum distance of residential areas.
Experts said that the risk of accidents that may occur PX project is divided into two categories: fire and explosion and chemical spills. The prediction results show fire and explosion at close range inside the building and staff will cause serious damage, but the impact of a range of about 100 meters. Statistics show that the petrochemical industry constitutes a significant environmental impact on the probability of an accident in the 1 × 10-5 / year, that is a case of hundreds of thousands of years.
Dalian Municipal Environmental Protection Bureau, said after the EIA identified and approved protective distance intermediate tank Dalian PX project, the combined unit and terminal tank People's Republic of China are in line with industry standards - Petrochemical Enterprises Health Protection (SH3093-1999).
However, Ma Tianjie believes that the current number of large chemical project EIA report also going through the motions of the problem does exist, because these large chemical project at every turn is billions, billions of investment, stimulating effect on the local economy is very obvious, This has resulted in a number of chemical projects "not approved the first building." He said, including Dalian PX project from media reports, before approving the construction had been started up. Many large chemical projects are built in environmentally sensitive areas, densely populated area.
马天杰 BASF Chongqing MDI project he is concerned, for example, "was planned in the Three Gorges reservoir area, a chemical plant in the upper reaches of the Yangtze .MDI like the product itself harm in general, but the production of MDI process using chemicals, For example, nitrobenzene, which are great harm, so in consideration of environmental risks when a project, not only consider what it produces, but also consider what it is used, as these are likely to be stored in their A growing areas or areas around it, then they should also be counted in the risks. "
"Because of this, such as chemical projects are generally built on the environmental risk areas, environmentally sensitive areas, giving rise to public concern, I think these fears are reasonable." Ma Tianjie said.
Who participated in the Dalian PX project EIA report, experts say that the first phase of the EIA report of 400,000 tons in question did not involve the breakwater, the project site is very far from the sea in a place where 80 meters high, can not see Less than sea. However, in the course of the Phase II expansion, by the Liaoning Provincial Environmental Protection Bureau is responsible for approving environmental reporting, planning to produce a change in the design of the raw material tank at the beach and other facilities, and designed breakwater.
Large chemical projects widespread problem of inadequate information disclosure
Ministry of Environmental Protection experts who participated in the demonstration project also pointed out earlier, Dalian PX project in Dalian know very few people, the government information disclosure on well enough.
Senior director of Greenpeace pollution prevention projects 马天杰 said Chinese environmental projects, there are many deficiencies in the information disclosed on. "First of all in the planning, there is no public consultation or environmental impact assessment or EIA report, not open to the public, or is it limited to the public." 马天杰 said.
He told reporters that many established a production plant of multinational companies in China, in their own country or other countries voluntarily disclosed this information, but in China did not. Chinese law is not perfect, and some government departments do not act, so that they loopholes. This will inevitably result in completion of the project after the public is not an acceptable degree of acceptance is very low. "Relevant information is not public is the direct cause of public panic." 马天杰 that experience abroad is a very basic steps of information disclosure and listen to public opinion before the project should be done, is.
In addition, the EIA report should also be open to the public and expert opinions have the opportunity to participate, so that they fully express their views, the possible risks into account, in this context re-construction of the project, so as to ensure that the project to a greater extent security.
August 16, Dalian municipal government held a special meeting to hear Fujia PX project discontinued the progress of work on the next steps for deployment. However, the anonymity of chemical experts say that for chemical plants, the shutdown and relocation did not think so simple, compared to production processes, it is more likely to cause problems, chemicals once contained benzene leak and explosion The consequences could be disastrous. In addition, more than two years for a newly launched projects, companies have invested billions, is facing shutdown and relocation, including the loss of who is responsible for the problem.