The runway contains an ingredient called toluene diisocyanate (TDI). The substance produced by toluene diisocyanate will release toluene diisocyanate gas under high temperature or strong light, which is very harmful to human body.
It is undeniable that TDI itself is a toxic substance in terms of toxicity. According to foreign data, about 3% ~ 5% people are allergic to it, which may aggravate asthma after inhalation into the nasal cavity. Its toxicity mainly comes from two aspects: first, it is relatively toxic when processed in factories.
TDI is in the raw material state when it is processed in the factory. Once heated, it is easy to volatilize and has certain toxicity. However, if we put an exhaust pipe on the reactor, which leads to the treatment tank and TDI is soluble in water, the toxicity problem can be solved. The second aspect is that there will be some free TDI in the site construction, so the smell will be smelled in the plastic site or the plastic track laying site.
However, it should be emphasized that after TDI reaction and curing, the original substance combines with molecules, so it no longer volatilizes and its toxicity basically does not exist. Therefore, I personally think there is no need to doubt that TDI will be emitted from plastic runways and plastic roads.
The main component of plastic stadiums and runways is polyurethane elastomer. As far as it is concerned, it is a kind of thing with good biological digestibility. According to records, the first half membrane of artificial heart is made of polyurethane elastomer.
At the same time, compared with polypropylene, polydecene and polychloroprene in plastics, these substances are easy to decompose. When it is buried underground, microorganisms will erode it and decompose it. Therefore, the notoriety of' Millennium garbage' is impossible to talk about.
Extended data:
I. National standards
The compulsory national standard "Sports Ground for Synthetic Materials in Primary and Secondary Schools" is organized by the Ministry of Education and drafted by dozens of scientific research institutes and testing institutions. After more than two years of revision, it was implemented on 20 18 1 1.
The new national standard draws lessons from the relevant standards at home and abroad, and solves the outstanding problems such as safety, environmental protection and sports protection in the construction of synthetic ground sports venues.
Considering the main risk points in all aspects of the life cycle of synthetic material ground sports ground in primary and secondary schools, various technical indicators that meet the requirements of green development, technological progress, industry norms and students' health protection are put forward.
Compared with the old national standard, the new national standard has not only changed from "national recommended standard" to "national mandatory standard", but also added many contents, including thickness requirements, physical properties, inorganic filler content requirements, anti-slip rubber particle polymer content requirements, harmful substances limits of surface finished products, and harmful substances limits of non-solid and solid raw materials.
The reporter of Beiqing Daily saw that the new national standard stipulated the limit of 18 kinds of harmful substances that may be generated in the construction of campus plastic runways, and limited the volatile organic compounds of the completed runways according to the home improvement standards.
For example, in the Limits and Odor Requirements for Cast-in-place and Precast Paving Products, the release amount of harmful substances shall not be higher than 5mg/m3, formaldehyde 0.4mg/m3, carbon disulfide 7mg/m3, benzene 0. 1mg/m3, and the odor grade is 3.
The new national standard also specifies the sampling requirements, inspection rules and judgment rules of plastic runways in primary and secondary schools. In addition, the campus artificial lawn has also been included in the national standard for the first time.
Second, the main components of the plastic runway
The main components of the plastic track are acrylic acid and high-quality resin, and its material is similar to the convenient bag for holding food, which meets the requirements of environmental protection surface materials.
The raw materials of the plastic track have been certified by the National Plastics Industry Association, which is non-toxic and harmless to the environment and human body. And has the characteristics of ultraviolet resistance, wear resistance, explosion resistance, aging resistance, long service life, easy maintenance, low maintenance cost and the like.
References:
Baidu encyclopedia-plastic runway
People's Network-Plastic Runway, Where to Go?