The adverse factors affecting indoor air quality include physical, chemical and biological factors. indoor air pollution Mainly man-made pollution, among which Chemical pollution Most prominent. stay Indoor air quality parameters In, most of the pollutant parameters are slightly different according to different reference standard parameters, but the main parameters are still the same. Indoor air quality pollutant parameters mainly include formaldehyde 、 benzene And its homologues, total volatile organic compounds（ TVOC ）、 ammonia 、 radon 、 carbon dioxide 、 carbon monoxide , PM10, benzo [a] pyrene, microorganism, ozone nitrogen oxide 、 sulfur dioxide 。 formaldehyde
1. Hazards of formaldehyde:
Research on carcinogenicity of formaldehyde shows that formaldehyde has serious harm to human health. When the content of formaldehyde in indoor air is 0.1 mg per cubic meter, it will produce odor and discomfort; 0.5 mg per cubic meter can stimulate eyes and cause tears; 0.6 mg per cubic meter causes throat discomfort or pain; Higher concentrations can cause nausea, vomiting, cough, chest tightness, asthma and even emphysema; When the air reaches 30 milligrams per cubic meter, it can even cause immediate death. In addition, formaldehyde has teratogenic and carcinogenic effects.
2. Physical and chemical characteristics of formaldehyde:
Formaldehyde (HCHO), also known as formic aldehyde, is a colorless gas with strong pungent odor. Its relative density to air is 1.067, slightly heavier than air, and is easily soluble in water, alcohol and ether. Its 30%~40% aqueous solution is formalin solution. Formaldehyde easy polymerization synthesis Paraformaldehyde When heated, it is prone to depolymerization and can slowly release formaldehyde at room temperature. 3. Source of formaldehyde:
Formaldehyde is an air pollutant with a wide range of sources. Formaldehyde in nature is an intermediate product in the methane cycle. The low background value is generally less than 0.03 mg/m3, and the annual average concentration of formaldehyde in urban air is about 0.005~0.01 mg/m3. Formaldehyde in outdoor air mainly comes from the combustion of oil, coal, natural gas and other fuels, the oxidation and decomposition of lubricating oil, automobile emissions, and atmospheric photochemical reaction. Formaldehyde in the atmosphere also comes from the production of formaldehyde Urea formaldehyde resin 、 Chemical fibre , dye Rubber products , plastic, ink, paint, paint factory. Indoor formaldehyde comes from buildings Decorative materials Furniture, various adhesive coatings, synthetic fabrics, etc. Benzene and its homologues
1. Hazards of benzene and its homologues:
Benzene can cause anesthesia and irritation of respiratory tract, accumulate in nervous tissue and bone marrow, and destroy hematopoietic function (the destruction of red blood cells and white blood cells Thrombocytopenia ）, long-term contact will cause serious consequences. The main effect of toluene and xylene is to central nervous system And cause mucous membrane irritation. 2. Physical and chemical properties of benzene and its homologues:
Benzene and its homologues and xylene are colorless, aromatic, volatile, flammable and low ignition point gases. These compounds are slightly soluble in water and easily soluble in ether, ethanol, chloroform and carbon disulfide And other organic solvents. Xylene has three isomers: ortho, meta and para. Generally, the meta site accounts for 45%~70%, the para site 15%~25%, and the adjacent site 10%~15%. The physical and chemical properties of the three isomers are very similar. 3. Sources of benzene and its homologues:
Benzene can be extracted from coal tar and petroleum, and can be used as fuel and spice. It is an important raw material for organic synthesis, and can be used as fat, ink, paint and rubber solvent, and as solvent in printing and leather industries. Benzene can be used to manufacture detergents, pesticides and disinfectants; Solvents and cleaning agents used in precision optical instruments, electronic industry, building decoration materials and Wood-based panel furniture It is used as adhesive, solvent and additive in sofa. Benzene will be volatilized in the use of the above substances, and indoor benzene in decoration mainly comes from solvent coatings for woodenware 。 The concentration of benzene and toluene in newly decorated rooms was detected to be very high, reaching 1000~2000 micro per cubic meter of air; g， Even higher. The benzene exposure of smokers (90%) mainly comes from mainstream cigarette smoke. The average body load of smokers is 6-10 times that of non-smokers. In the United States, half of the total benzene exposure is caused by smokers. For non-smokers, benzene exposure mainly comes from the evaporation of automobile exhaust gas or gasoline, including outdoor air and gasoline evaporation in domestic parking lots indoor air pollution , and benzene exposed in individual activities (such as driving). Total Volatile Organic Compounds (TVOC)
1. Volatile organic compound hazards:
With chemicals and various Decorative materials With the widespread use of, the types of other indoor pollutants, especially volatile organic compounds (VOC), are increasing. Generally, total volatile organic compounds (TVOC) is used as an indicator of indoor air quality (IAQ) to evaluate the health and discomfort effects of VOC exposure. The hazards identified and suspected by VOC mainly include five aspects: odor discomfort, sensory stimulation, local tissue inflammation, allergic reaction, and neurotoxicity. 2. Physical and chemical properties of volatile organic compounds:
Volatile organic compounds (VOC) refer to those at room temperature Saturated vapor pressure For organic matter with a boiling point of more than 70.91 Pa or less than 260 ℃, the main components of VOC are aromatic hydrocarbon, halogenated hydrocarbon, oxyhydrocarbon, aliphatic hydrocarbon, nitrogen hydrocarbon, etc. There are as many as 900 kinds of VOC. VOC is a strong volatile, toxic organic gas with special pungent odor, and is one of the important indoor pollutants. Some have been listed as carcinogens, such as vinyl chloride, benzene, polycyclic aromatic hydrocarbons, etc. Most VOCs are flammable and explosive, posing a threat to the safety of production enterprises. Some VOCs have a destructive effect on the ozone layer, such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). 3. Sources of volatile organic compounds:
VOC is the most common pollutant discharged from petroleum, chemical, pharmaceutical, printing, building materials, spraying and other industries. In addition to being affected by outdoor air pollution, indoor VOC is closely related to complex indoor decoration materials, indoor pollution source emissions, human activities, etc.
1. From plywood used for interior decoration Joinery board , medium density fiberboard, particleboard, etc Artificial plate 。 Because formaldehyde has a strong adhesive property, it also has the function of strengthening the hardness of the board and preventing insects and corrosion, so the adhesive used in the production of wood-based panels is mainly composed of formaldehyde Urea formaldehyde resin The residual formaldehyde in the plate and the formaldehyde not participating in the reaction will gradually release to the surrounding environment, which will lead to the excessive formaldehyde content in the indoor air. 2. From furniture made of wood-based panels. In particular, some furniture manufacturers, in order to pursue profits, use substandard boards, and the manufacturing process is not standardized, making furniture a formaldehyde discharge station.
3. From other decorative materials containing formaldehyde, such as white latex, foam plastic, paint and coatings.
4. From interior decoration textiles, including bedding Wallcovering , wallpaper, chemical fiber carpet, curtain and fabric furniture. How to prevent formaldehyde pollution caused by decoration?
1. In the design of decoration and fitment, special attention should be paid to indoor environmental factors, reasonable collocation of decorative materials, full consideration of the carrying capacity and ventilation of indoor space, and improvement of indoor air quality.
2. The construction process of interior decoration shall be non-toxic, less toxic, pollution-free and less polluting. The saw mouth where the wood-based panel is used shall be coated with paint to fully solidify it, which can form a stable protective layer to prevent formaldehyde emission in the panel.
3. In the selection of interior decoration materials, qualified interior decoration materials should be selected in strict accordance with national standards. The country has formulated ten mandatory standards of Limit of Harmful Substances in Interior Decoration Materials. Consumers must choose color products that are pollution-free or less polluting and conducive to consumer health when decorating. Use adhesive without formaldehyde, formaldehyde free core board Veneer Etc. What are the methods for removing formaldehyde after home decoration?
1. More ventilation in the room. The content can be reduced through the circulation of indoor air.
2、 Activated carbon adsorption method 。 Formaldehyde removal by activated carbon is a relatively cheap and practical method, characterized by physical adsorption. 3. Plant deodorization. Planting aloe, cactus and other green plants to purify the air.
4. Use formaldehyde effect essence to remove formaldehyde, quickly remove formaldehyde, and the effect is lasting.
What are the hazards of formaldehyde to pregnant women in home decoration?
When the concentration of formaldehyde in the indoor air of pregnant women exceeds 0.24 to 0.55 mg per cubic meter, it directly affects the circulatory system, immune, reproductive and metabolic functions of pregnant women, and is prone to headache, fatigue, fatigue, irritability, excitability, insomnia and other symptoms, and may even cause pregnancy syndrome, neonatal chromosomal abnormalities, and ultimately lead to fetal malformation, abortion Fetal brain development is impaired, Congenital heart disease And other congenital defects. Especially the babies and mothers in the first three months of pregnancy are the weakest! When special care. This shows that formaldehyde does great harm to pregnant women and fetuses, and it is urgent to treat formaldehyde. The expectant parents should gradually improve their awareness of preventing formaldehyde, benzene series, ammonia, TVOC and other harmful gases, take the initiative to improve the indoor environment, care for the next generation, and create a safe and comfortable environment for pregnant women.
How should the house after decoration detect and manage indoor formaldehyde in time?
1. For newly decorated houses and newly purchased furniture, or when the indoor air quality is poor, it is better to ask a qualified testing unit for testing.
2. It is not suitable to move in immediately after decoration. Windows should be opened and ventilation should be carried out to let the indoor polluted air emit. High temperature, high humidity and negative pressure will accelerate the emission of formaldehyde. Strengthening the ventilation frequency is conducive to the emission and discharge of formaldehyde. Generally speaking, after several months of decoration, the indoor formaldehyde concentration can be reduced to below 0.08mg/m3, reaching the indoor standard standard 。 3. If the formaldehyde in the indoor environment has exceeded the standard, it should be treated in time. Formaldehyde treatment products can be selected:
① air cleaner : It can adsorb indoor formaldehyde and other pollutants to a certain extent. ② Deodorant and Formaldehyde scavenger : It can effectively reduce free formaldehyde in wood-based panels when used in decoration projects. ③ Harmful gas adsorber, furniture adsorber: it can catalyze the decomposition of indoor formaldehyde and other harmful gases.
④ Formaldehyde sealant: painted on the inner wall panels and wood-based panels of furniture without paint treatment to reduce Formaldehyde emission 。 ⑤ One time after decoration, professional construction, reduce the pollutant content in the pollution source through accelerated release.
National《 Code for residential design 》(GB50096-2011): 7.5.3 residence Indoor air Contaminants The activity and concentration of shall comply with the provisions in Table 7.5.3. Table 7.5.3 Residence Indoor air pollutants Limits Name of pollutant Activity and concentration limit
preface
This standard is formulated to protect human health and prevent and control indoor air pollution.
Appendix A, Appendix B, Appendix C and Appendix D of this standard are normative.
This standard is issued for the first time.
This standard is formulated by the Ministry of Health State Environmental Protection Administration 《 Indoor air quality standard 》Draft by the joint drafting group. This standard is mainly drafted by: China Center for Disease Control and Prevention Environment and Health Related Product Safety Institute Institute of Environmental Standards, Chinese Academy of Environmental Sciences, Institute of Radiation Protection and Safety, China Center for Disease Control and Prevention, School of Environment, Peking University ， School of Environmental Science and Engineering, Nankai University Beijing Institute of Labor Protection, School of Architecture, Tsinghua University Ecological Environment Research Center of Chinese Academy of Sciences, Environmental Engineering Institute of Chinese Academy of Building Materials Sciences. This standard was approved by the General Administration of Quality Supervision, Inspection and Quarantine, the Ministry of Health and the State Environmental Protection Administration on November 19, 2002.
This standard is proposed by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China.
This standard is prepared by State Environmental Protection Administration And the Ministry of Health. 1 Scope
This standard specifies Indoor air quality parameters And inspection methods. This standard is applicable to residential and office buildings. Other indoor environments can refer to this standard.
2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For dated reference documents, all subsequent amendments (excluding corrigendum) or revisions are not applicable to this standard. However, parties to agreements based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest version is applicable to this standard.
GB/T 9801 Air Quality carbon monoxide Non dispersive infrared method GB/T 11737 Standard Method for Hygienic Inspection of Benzene, Toluene and Xylene in the Atmosphere of Residential Areas Gas chromatography GB/T 12372 Residential Area Atmosphere Nitrogen dioxide The improved Saltzman method of inspection standard method GB/T 14582 Standard Measurement Method for Radon in Ambient Air
GB/T 14668 Air Quality - Determination of Ammonia Nessler's reagent colorimetry GB/T 14669 Air Quality Determination of Ammonia Ion Selective Electrode Method
GB 14677 Air Quality Determination of Toluene, Xylene and Styrene Gas Chromatography
GB/T 14679 Air Quality - Determination of Ammonia sodium hypochlorite - Salicylic acid spectrophotometry GB/T 15262 Ambient Air sulfur dioxide Determination of formaldehyde absorption pararosaniline spectrophotometric method GB/T 15435 Ambient Air Nitrogen dioxide Saltzman method GB/T 15437 Determination of Ozone in Ambient Air Indigo Disulfonate Sodium Spectrophotometry GB/T 15438 Ambient Air Determination of Ozone Ultraviolet Photometric Method
GB/T 15439 Ambient air Determination of benzo [a] pyrene High performance liquid chromatography
GB/T 15516 Air Quality Determination of Formaldehyde Acetylacetone Spectrophotometry GB/T 16128 Standard method for hygienic inspection of atmospheric sulfur dioxide in residential areas Formaldehyde solution Absorption- Aniline hydrochloride Spectrophotometry GB/T 16129 Standard method for hygienic inspection of formaldehyde in air of residential areas Spectrophotometric method
GB/T 16147 Measurement Method of Radon Concentration in Air by Scintillation Bottle
GB/T 17095 Indoor Air Inhalable particles hygienic standard [1] 
