Benzene (C6H6)
"Benzene", commonly known as Tianna water, is a colorless and transparent liquid with a special aromatic smell, which is volatile and flammable. Steam has the property of * * *, and volatilizes quickly at room temperature.
What people usually say is actually a series of substances, including benzene, toluene and xylene. Toluene, xylene and benzene homologues are all products of coal tar fractionation or petroleum cracking.
When people inhale high concentrations of toluene and xylene in a short time, they may suffer from central nervous system anesthesia, ranging from dizziness, headache, nausea, chest tightness, fatigue and confusion to coma, leading to respiratory and circulatory failure and death. If long-term exposure to a certain concentration of toluene and xylene will cause chronic poisoning, there may be neurasthenia symptoms such as headache, insomnia, listlessness and memory loss.
Benzene compounds have been identified as strong carcinogens by the World Health Organization. Benzene compounds have been identified as strong carcinogens by the World Health Organization, and it is also recognized by the medical community that benzene can cause leukemia and aplastic anemia.
Sources of benzene and benzene series:
Because benzene aromatic hydrocarbons are generally not easy to arouse people's vigilance. Cause methemoglobinemia and hemolysis and liver injury. Benzene in home and office buildings mainly comes from a large number of chemical raw materials used in building decoration, such as paints, fillers, various organic solvents, etc., which contain a large number of organic compounds and volatilize indoors after decoration. Mainly in the following decorative materials are higher.
Painting. Benzene compounds are mainly volatilized from paint, and benzene, toluene and xylene are indispensable solvents in paint.
Additives and diluents for various paints and coatings. Benzene exists in a large number of organic solvents in various building decoration materials, such as natural water and diluent in decoration. The main components are benzene, toluene and xylene.
Various adhesives. In particular, solvent-based adhesives still have a certain market in the decoration industry. Most of the solvents used are toluene, and the benzene content is above 30%. However, due to reasons such as price, solubility and adhesiveness, they are still adopted by some enterprises. Some sofas bought by families release a lot of benzene, mainly because of the use of adhesives with high benzene content in production.
Waterproof material. Especially for some waterproof coatings made of raw powder and thinner, after running for 15 hours, the benzene content in indoor air exceeds the highest concentration allowed by the state 14.7 times.
Some low-grade and fake paint. It is also an important reason for the excessive benzene content in indoor air.
formaldehyde
Colorless gas, with strong pungent smell, easily soluble in water, alcohol and ether. Highly toxic, formaldehyde ranks second in the priority control list of toxic chemicals in China.
Formaldehyde has been identified as a carcinogen and teratogenic substance by the World Health Organization. It is considered as an allergen and one of the potential strong mutagens. The boiling point of formaldehyde is 19℃, and the volatilization period is 3- 15 years. When the temperature exceeds this temperature, the release will rise sharply. Free formaldehyde in the air will be more active, especially the elderly and children at home are sensitive and vulnerable to pollutants.
The effects of formaldehyde on human health are mainly manifested in abnormal sense of smell, irritation, allergy, abnormal lung function, abnormal immune function and so on, which vary greatly from individual to individual. (When the formaldehyde concentration is 0.06 ~ 0.07 ㎎/m3, children can suffer from asthma. Babies are prone to leukemia.
Sources of formaldehyde:
Formaldehyde is the raw material for manufacturing synthetic resin, paint, plastic and man-made fiber, and it is also an important raw material for manufacturing urea-formaldehyde resin adhesive, melamine resin adhesive, polyacetal resin, pentaerythritol aldehyde resin and phenolic resin adhesive in wood-based panel industry. They will gradually release residual or unreacted formaldehyde to the surrounding environment, and the longest release period can reach more than ten years. The binder decomposes when it meets water to generate free formaldehyde, which moves and accumulates continuously on the board surface, then separates from the board surface and volatilizes and diffuses into the air.
Wood-based panels such as plywood, blockboard, medium density fiberboard and particleboard;
Wall covering, wallpaper, chemical fiber carpet, paint, coating and other decorative materials.
Volatile organic compounds (TVOC)
Commonly used decoration materials, such as paint, coating, floor leather, wallpaper, plywood, plastic, imitation PVC board, thermal insulation materials, as well as indoor artificial boards, such as plywood such as large core board and willow, medium density fiberboard furniture, artworks, etc., will release volatile organic compounds. The US Environmental Protection Agency has identified 350 species, mainly aromatic hydrocarbons and aliphatic hydrocarbons. Different decorative materials have different pollution periods. Three common decorative materials, floor leather, paint and wallpaper, were tracked and measured in China. It was found that the pollution periods of these three materials were 65438 0 months, 2 months and 3 months respectively.
Indoor volatile organic compounds can irritate skin, mucous membrane and nervous system, leading to a series of allergic symptoms and abnormal neurobehavior. Pathological study found that the stability of tear film decreased, the composition of tear cells changed, the content of albumin increased, nasopharyngeal congestion and a large number of inflammatory cells existed. Animal experiments show that it is potentially mutagenic, teratogenic and carcinogenic.
radon (Rn)
Indoor radon mainly comes from building foundation, indoor ground and its surrounding soil, rocks, building materials, water supply and outdoor air. The United States, Japan, France, Germany, Denmark, Switzerland and other countries have reported on indoor radon pollution. Radon is the most important radiation source in people's lives, and 40% of the annual effective dose of natural radiation comes from radon and its daughters. A large number of investigations at home and abroad have confirmed that high concentrations of radon and its daughters can cause lung cancer. According to the statistics of the World Health Organization, radon has become the second largest cause of lung cancer after smoking.
other
Decoration materials will slowly release some other chemicals harmful to human body. For example, natural stone and ceramic products can precipitate fluoride, sulfide, lead, nickel, chromium, cobalt and other metal substances, which enter the human body through ways such as polluting diet, contacting skin or forming aerosol. Commonly used paints, coatings and plastics all contain lead. A survey of children aged 1 1 urban child care institutions11kloc-0/2-6 found that the blood lead level of children in decorated families.
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