2014年5月13日星期二

Home decoration green

Home decoration environmental problems , mainly concentrated in three areas: radon , TDI, formaldehyde.

A radon
Radon is definitely a new term , but for everyone speculation about, the word may be the only physical / chemist will use it . So we have to first understand what is radon up .
Radon is actually the first 86 elements of the periodic table, at the sixth cycle zero family , the element name Rn. Is an inert gas. There are three natural isotopes of radon 222Rn, 220Rn, 219Rn, commonly referred to as the main means of radon 222Rn, 222Rn is a natural radioactive decay series of uranium-series of intermediate half-life of 3.825 days , radon parent element is uranium, uranium decay produce radon .
Here , we can at least understand two points:
1 , radon is a natural substance .
2 , radon is radioactive build deck bench seat.
Radon major hazards:
Radon is almost ubiquitous , including soil , water , stone, and other building decoration materials may contain more or less of radon . Radon is colorless and odorless , radon superscalar radioactivity will increase the incidence of lung cancer

Two , TDI
TDI (toluene diisocyanate / toluene diisocyanate). Toluene diisocyanate is used in one kind of polyisocyanate , and the polyisocyanate is more than a polyurethane (PU) material and an important base material . TDI polyurethane industry is the most commonly used 2,4-TDI and 2,6-TDI mixture of two isomers ratio 80.20 constitution , mainly for the production of flexible polyurethane foam and polyurethane elastomers , coatings , adhesives and the like.
TDI major hazards:
TDI in the decoration of the main projects exist in the paint , beyond the standard free TDI harm to human body . Free TDI on the human body is mainly sensitization and stimulation , including pain caused tearing, conjunctival congestion, cough, chest tightness, shortness of breath, asthma, red pimples, rash , contact dermatitis and other allergic symptoms . International standards for free TDI limit is controlled below 0.5% .

Third, formaldehyde
Speaking of formaldehyde, we have to know what is formaldehyde. Formaldehyde, MF HCOH, yes yes a colorless, pungent gas . Specific Gravity 0.815 (-20 ℃), melting point -92 ℃, boiling point -19.5 ℃, ignition about 300 ℃; soluble in water and ethanol , a strong reduction in alkaline solution . 40% formaldehyde solution called " formalin " , the boiling point of this solution is 19 degrees , so very volatile at room temperature , heat even more.
Formaldehyde is an important organic chemical raw material , widely used in synthetic resin , engineering plastics POM, pesticides, pharmaceuticals, dyes and other industries, mainly used as a disinfectant , but also as a binder for the hexamine , phenolic resins, urea-formaldehyde resin , synthetic resin, synthetic fiber , plastic polyoxymethylene , trimethylol propane and the like materials vinyl fence sale.
www.10000xiang.net national safety standards for formaldehyde is such a requirement :
1 , on human health content maximum allowable concentration of air 0.08mg / m composite garden furniture uk.
2 , parquet formaldehyde content is: A class of parquet formaldehyde emission is less than equal to 9 mg / 100 g (9mg/100g); class B parquet formaldehyde emissions than 9 mg -40 mg / 100 g (9mg-40mg/100g)
3 , artificial board formaldehyde emission should be less than 0.20 mg / m (0.20mg/m3);
4 , wood flooring formaldehyde emission should be less than 0.12 mg / m (0.12mg/m3).
The main hazards of formaldehyde :
Indoor content is there odor and discomfort 01 mg / cubic meter ; 0.5 mg / cubic meter can irritate the eyes , causing tears ; 0.6 mg / cubic meter can cause throat discomfort or pain ; high concentrations can cause nausea , vomiting , cough , chest tightness , wheezing, or pulmonary edema . Long-term exposure to low doses of formaldehyde can cause respiratory diseases and even cause nasopharyngeal cancer .

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