Characteristics of formaldehyde:
Formaldehyde is a colorless gas with a strong smell. Soluble in water, alcohol and ether. Formaldehyde is gaseous at room temperature and usually exists in the form of aqueous solution. Its 37% aqueous solution is called formalin, which is used by medical and scientific research departments for long-term preservation of specimens. The boiling point of this solution is 19.5℃, which is volatile at room temperature, and the volatilization speed increases with the increase of temperature. 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.
Use of formaldehyde:
Formaldehyde was widely used in industrial production 100 years ago because of its strong chemical reaction and low price.
* Formaldehyde is a very strong bactericide, which is widely used for the preservation of specimens in hospitals and scientific research departments;
* Some inferior waterborne interior wall coatings and white latex also use formaldehyde as a preservative;
* Some unscrupulous businessmen also use it to keep food (such as seafood and rice noodles) fresh.
* Formaldehyde is widely used in industrial production. It is a raw material for manufacturing synthetic resin, paint, plastics and man-made fibers, and also an important raw material for adhesives used in wood-based panel industry (urea-formaldehyde resin adhesive, melamine resin adhesive and phenolic resin adhesive). At present, urea-formaldehyde resin adhesive (UF) is mainly used in the production of wood-based panels (including plywood, core board, medium density fiberboard and particleboard) in the world. Urea-formaldehyde resin adhesive is made from formaldehyde and urea through addition reaction and polycondensation reaction under certain conditions.
Indoor formaldehyde source:
Formaldehyde is an air pollutant with wide sources.
The formaldehyde in the outdoor air mainly comes from the combustion of oil, coal, natural gas and other fuels, the oxidative decomposition of lubricating oil, automobile emissions and atmospheric photochemical reactions. In addition, some factories that produce formaldehyde, urea-formaldehyde resin, chemical fiber, dyes, rubber products, plastics, ink, paints and coatings will also release a lot of formaldehyde.
Formaldehyde in indoor air mainly comes from building decoration materials, furniture, various adhesives, paints, synthetic textiles and so on.
Burning 1000 gallon of oil can produce 0.908 kg of formaldehyde.
Every kilogram of automobile exhaust contains 70 mg of formaldehyde.
Burning 1 ton of coal can produce 2.3g of formaldehyde.
Every kilogram of coal-fired flue gas contains 6 mg of formaldehyde.
Emission routes of formaldehyde:
1. Wood itself will release a very small amount of formaldehyde under the action of temperature and humidity.
2. In the process of manufacturing urea-formaldehyde resin, some free formaldehyde will inevitably remain in the outside world.
3. During the curing process of wood-based panel, part of linear resin did not form a network structure, and it was decomposed into free formaldehyde and distributed to the outside world.
4. The partially cured resin decomposes under the action of heat and moisture to form free formaldehyde.
5, indoor building decoration materials in the process of use, with the extension of temperature, relative humidity and use time. Continuously discharge formaldehyde to the outside world.
Indoor decoration materials and formaldehyde pollution in the air;
With the development of economy and the improvement of people's living standards, building decoration materials made of various raw materials have entered the family, and formaldehyde is recognized as a representative chemical that causes indoor air pollution. Building decoration materials that cause formaldehyde pollution and other reasons are:
1, decorative materials and new combination furniture are the main sources of formaldehyde pollution. The adhesive waste heat of plywood, core board, density board, particleboard and (particleboard) in decoration materials and furniture releases formaldehyde during deliquescence, which is the main source of indoor formaldehyde release.
2.UF foam is used as thermal insulation material for building heat and cold protection. Under the action of light and heat, the foam ages and releases formaldehyde.
3. Coatings, chemical fiber carpets, cosmetics and other products with formaldehyde as preservative.
4, indoor smoking, each cigarette smoke contains 20-88ug formaldehyde, and has a synergistic carcinogenic effect.
Harm of formaldehyde to human health;
1. Formaldehyde has a strong * * effect on human body panels and mucous membranes, which can coagulate intracellular protein and inhibit all functions of cells. Long-term exposure to low-dose formaldehyde will cause chronic respiratory diseases and cause nasopharyngeal carcinoma, colon cancer and brain tumor.
Gene mutation in nucleus, DNA single-strand crosslinking and DNA- protein crosslinking, and inhibition of DNA damage repair;
Pregnancy syndrome, chromosomal abnormality of newborn, leukemia, memory and intelligence decline of teenagers. Among all the contacts, children and pregnant women are particularly sensitive to formaldehyde, which is more harmful.
2. The methanol produced by formaldehyde in the body has strong damage to the optic colliculus and retina.
3. The effects of formaldehyde on human health are mainly manifested in abnormal sense of smell, * * *, allergy, abnormal lung function and abnormal immune function.
4. Formaldehyde is a highly toxic substance, ranking 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.
Limit value of formaldehyde concentration in indoor air:
In order to improve the indoor environment and protect the health of residents, in recent years, all countries have made strict regulations on the limit value of formaldehyde concentration in the air. China also promulgated the Hygienic Standard for Formaldehyde in Indoor Air in 1996, which clearly stipulated that the maximum allowable concentration of formaldehyde in indoor air was 0.08 mg/m3.
Because wood-based panels are the main factor leading to excessive formaldehyde in indoor air, many countries in the world have made strict regulations on the formaldehyde release value of wood-based panels. The international standard is that the perforation test value must be less than 10mg formaldehyde/100 g panel.
China Consumers Association asked the National Wood-based Panel Quality Supervision and Inspection Center to conduct a comparative test on 2 1 brand decorative boards sold in Beijing. At present, there is no regulation on formaldehyde emission from decorative veneer plywood in China. According to JAS No.516-1992, the formaldehyde emission index is clearly divided into three grades, and the highest grade is ≤ 100 mg formaldehyde/100 g board. Of the 2 1 sample tested, the formaldehyde emission of 15 samples exceeded the standard, accounting for 7 1.4%. The use of such products is bound to pollute the living environment and directly endanger the health of consumers.
Generally, the formaldehyde content of newly renovated houses can reach 0.4 mg/m3, and individual ones can reach 1.5 mg/m3.
Generally, in a room of 100㎡, if more than 20 artificial boards are used for decoration, the indoor formaldehyde will generally exceed the standard by more than 5 times.
Indoor formaldehyde content is closely related to the use time, ventilation conditions, temperature and relative humidity of the room. The longer the house is used, the higher the temperature and the lower the humidity, which is more conducive to the release of formaldehyde.
Indoor formaldehyde treatment method indoor formaldehyde removal method;
A, plant elimination method (chlorophytum, aloe)
Chlorophytum, Aloe Vera and Eupatorium adenophorum can absorb a lot of indoor formaldehyde and other pollutants to eliminate and prevent indoor air pollution.
Second, the adsorption method (activated carbon)
Adsorption is a solid surface phenomenon. Porous solid adsorbent is used to treat gaseous pollutants, so that one or more components are adsorbed on the solid surface under the action of molecular attraction or chemical bond force on the surface of solid adsorbent, thus achieving the purpose of separation. Activated carbon can adsorb benzene, toluene, xylene, ethanol, ether, kerosene, gasoline, styrene, vinyl chloride and other substances.
3. Chemical cleaning method: At present, air cleaners available in the market can actively absorb, capture and react formaldehyde free molecules in wood-based panels, and once they react to generate non-toxic polymer compounds, they will never decompose again, thus achieving the purpose of quickly and effectively eliminating formaldehyde.
Fourth, pay attention to ventilation.
Ventilation cannot be all-weather. The best time of the day is about AM 10:00: 00 and PM 15: 00. Optimal ventilation time: when the wind is strong, the best effect can be achieved within 30 minutes after the rain.
Verb (abbreviation of verb) air purifier
However, these products, plants and activated carbon are all physically absorbed, and their function is only to treat the symptoms, not the root cause, and only to deal with pollutants released into the air. In the environment with high pollution concentration, it takes a long time for this treatment method to have ideal effect, but in any case, it is better than nothing.
Have you done indoor formaldehyde treatment? I said that the overall effect of letting the company do it is not very good. It was really effective at the time. The formaldehyde content has dropped a lot. The problem is that after half a month, the formaldehyde content has come up again. I can't invite people once every half month. I still spent about 10 thousand to get the effect, not to mention those cheap effects.
Formaldehyde can be released continuously for several years, so it is better to do it yourself, and get some products that can last for a long time in in addition to formaldehyde and keep it in in addition to formaldehyde at home.
I bought Shi at that time, and the effect was very good, at least much better than activated carbon. Of course, the price is more expensive, but it can be used for more than three years. Basically, the formaldehyde content is within the normal range in about half a month, and it can be maintained all the time.
How to deal with indoor formaldehyde? Ventilation should be carried out for at least three months, and some effective formaldehyde control measures should be taken. Commonly used methods are: 1. In order to quickly remove the residual paint smell, cotton balls can be soaked in citric acid and hung indoors and in wooden furniture; 2. Always keep good ventilation to enhance volatilization. 3. It is also very effective to put items such as orange peel and lemon peel in the room, but their effect will not be quick. You can put two pots of salt water indoors, and the smell of paint will soon disappear. If it is the smell of paint from wooden furniture, you can scrub it with tea for several times, and the smell of paint will be eliminated faster; Of course, the most economical way to beautify the home is to put suitable flowers and plants at home. Plants that can absorb formaldehyde are cactus, chlorophytum, hibiscus (also known as gerbera), reed, ivy, cycad, chrysanthemum and so on. The flowers and plants that can eliminate xylene include ivy, cycad and chrysanthemum. 6. In order to use activated carbon in addition to formaldehyde, it should be placed in the corner of the bedroom. At present, this method is the fastest to remove odor, and it needs tiny pores to absorb harmful gases such as formaldehyde and toluene.
A professional cleaner for indoor formaldehyde control in Yuhang, Hangzhou, in addition to formaldehyde, can not only satisfy consumers' concerns about paint formaldehyde, but also purify the formaldehyde in the air, which is more considerate to consumers. It is really effective and worth recommending.
It is hard to say what department to find for indoor formaldehyde control. After all, it is good for you ordinary people to be tested by others. Although it is money, after all, people's authority is not. If you manage, you'd better do it yourself, so as not to look at others' faces. I can usually spray the herb Diyalin and keep it ventilated for several hours every day. It is the same to turn on the electric fan when the wind is light. As long as there is wind, strong wind is better.
How much is the indoor formaldehyde treatment? And it is incomplete to treat a disease only by feeling. It is also blind and unscientific;
If you want to control indoor formaldehyde, you must first carry out indoor air testing. What is the content and concentration of indoor formaldehyde?
Then there are many specific methods to suit the remedy to the case and treat it.
1 composite photocatalyst treatment technology; (2) formaldehyde scavenger; 3 activated carbon package 4 ventilation; Wait;
The provisions of the code for indoor environmental pollution control of civil construction projects.
Table of harmful substance concentration * * *
serial number
Indoor air pollutants
The concentration limit is 1 radon (bq/m3)≤200.
2 Free formaldehyde (mg/m3)≤0.08
3 Benzene (mg/m3) ≤0.09
4 ammonia (mg/m3) ≤0.20
5 TVOC(≤0.50)
The indoor air quality will be tested and accepted after the completion of the family room decoration project, and it can only be delivered after passing the acceptance.
Indoor formaldehyde treatment method, how in addition to formaldehyde flavor? First, open more doors and windows for ventilation.
Open the window for ventilation twice a day for at least fifteen minutes each time. This is a newly renovated house. Whether we want to do professional indoor environmental pollution control, we must do one thing. Ventilation is conducive to the discharge of indoor pollutants, effectively reducing the concentration of pollutants, and also allowing toxic and harmful gases in decoration materials to be released as soon as possible, refreshing the air.
Second, adsorption with activated carbon.
Activated carbon is an internationally recognized expert on drug abuse. The physical function of activated carbon deodorizes and detoxifies, without chemical additives, and has no influence on human body. When activated carbon is used for adsorption, doors and windows cannot be kept open, and a closed space can ensure excellent adsorption effect. This method can be used in conjunction with other methods of removing herbs, and the comprehensive control effect is better. That is, activated carbon is easily saturated, and now it is replaced by nano-active ore, which naturally has a good adsorption effect and the nano-pore size is greatly increased.
Third, using plant adsorption.
Some plants, such as chlorophytum, Eupatorium odoratum, Eupatorium odoratum, Phyllostachys pubescens, and Euphorbia fischeriana, have certain effects on absorbing formaldehyde. Although the efficacy is limited, it can be used as an auxiliary means of indoor environment management.
What if the indoor formaldehyde exceeds the standard? Changsha formaldehyde control, Changsha new house formaldehyde control harmful gases in newly renovated rooms. According to the national standard "Code for Indoor Environmental Pollution Control of Civil Building Engineering", five pollutants, namely free formaldehyde, benzene, ammonia, radon and TVOC, are listed for control.
Formaldehyde is a colorless and soluble gas. Wood-based panels such as particleboard, density board, plywood, adhesive and wallpaper are the main sources of formaldehyde in the air, and the release period is as long as 3 ~ 15 years. It can be absorbed through respiratory tract, and the harm of formaldehyde to human body has the characteristics of long-term, latent and concealed. Long-term inhalation of formaldehyde can cause serious diseases such as nasopharyngeal carcinoma and laryngeal cancer.
Benzene is a colorless gas with a special aromatic smell. Glue, paint, coating and adhesive are the main sources of benzene in the air. Benzene and benzene series can be anesthetized by the central nervous system after being inhaled by human body; It can inhibit human hematopoietic function, reduce red blood cells, white blood cells and platelets, and increase the incidence of aplastic anemia; It can also lead to abnormal menstruation in women and congenital defects in the fetus.
Radon is a colorless, odorless and imperceptible inert gas. Building materials such as cement, brick sand, marble and ceramic tiles are the main sources of radon, and a large amount of radon will also be released in geological fault zones. Radon and its daughters enter the human body with air, or attach to tracheal mucosa and lung surface, or dissolve in body fluids and enter cell tissues, forming internal irradiation, which induces lung cancer, leukemia and respiratory diseases. According to the research of the World Health Organization, radon is the second largest carcinogen of lung cancer after smoking.
Ammonia is a colorless gas with a strong smell. It mainly comes from additives such as concrete antifreeze and flame retardant in fire protection board. It has a strong * * effect on eyes, throat and upper respiratory tract, and can cause poisoning through panels and respiratory tract. Mild cases can cause congestion, increased secretion, pulmonary edema, bronchitis and dermatitis. Severe cases can cause laryngeal edema, laryngeal spasm, dyspnea, coma and shock, and high ammonia content can even cause reflex respiratory arrest.
TVOC is the abbreviation of VOC and volatile organic compounds, and it is a heterogeneous pollutant in indoor air. Because of their low concentration and many kinds, they are generally not represented one by one, but their total amount is represented by TVOC. TVOC includes benzene, toluene, butyl acetate, ethylbenzene, p (m) xylene, styrene, o-xylene and undecane. Indoor building and decoration materials are the main sources of TVOC in the air. The research shows that even if the content of single VOC in indoor air is lower than its limit, the mixed existence and interaction of multiple VOCs will increase the hazard intensity. TVOC is toxic, which can cause imbalance of immune level, affect the function of central nervous system, and cause dizziness, headache, lethargy, fatigue, chest tightness and other symptoms, and may also affect the digestive system, such as loss of appetite and nausea. In severe cases, it will damage the liver and hematopoietic system, and even lead to death.
How long can a newly renovated house live if it is ventilated? You can't just look at the length of time. If the air is up to standard after interior decoration, you can check in immediately. On the contrary, although the house has been renovated for a long time, the indoor air is still not up to standard, so it is still uninhabitable.
According to the relevant standards of the National Code for Indoor Environmental Pollution Control of Civil Building Projects, the indoor air quality inspection and acceptance should be carried out after 7 days of completion or before delivery, that is to say, it should be at least 7 days after the completion of the decoration, and the occupancy can only be carried out after passing the air quality inspection and acceptance.
Because indoor air pollution directly harms health and life, we should realize the seriousness of indoor air pollution and seek ways to detect and control indoor air pollution. However, there are still many people who have insufficient understanding of whether indoor air monitoring is needed after renovation. Some of them are very troublesome and think that they will not do too much harm to their health. Just open the doors and windows and put some green plants in the room. Some people think that the indoor smell is not big and there is no need for testing; Others think that the decoration materials are carefully selected by themselves and there will be no pollution. In fact, many harmful substances in decorative materials are indistinguishable from the naked eye and the sense of smell. Benzene series, for example, have little smell, but are very harmful to human body. Another example is radioactive gas radon, which has no smell, but can cause lung cancer, which is the second largest risk factor after smoking. Therefore, every family and individual must have a clear understanding and cognition of indoor decoration pollution. We should understand that once air pollution does harm to our health, it will not only affect our work and study, but also bring a heavy economic burden to our families. What's more, if leukemia and lung cancer are caused by pollution, it is very difficult to treat and even life-threatening.
Relevant environmentalists and experts believe that it is very important to understand indoor air pollution scientifically and control it in time. Houses that seriously exceed the standard must be handled by professional concentration before they can live safely. Professionals suggest that the correct way to control indoor air pollution is to detect indoor air first to determine the pollution degree and main harmful components, and then choose the appropriate control method to remove harmful gases according to the situation that harmful gases exceed the standard. On the basis of centralized treatment, the harmful gases released slowly in the future will be absorbed and oxidized by long-acting air bactericide, so as to eliminate the newly released harmful gases to the maximum extent and achieve the purpose of purifying the air for a long time. In short, after the room is renovated, don't forget to check it first, so as not to move into the "gas chamber" and endanger health and life!
Where is the indoor formaldehyde treatment in Xuzhou? Xuzhou has taken a lot of exams in recent years, but not many have officially registered. According to a friend from the Central Industrial and Commercial Department, Central Green Health and Meierjia are officially registered.
Xingke sells musical instruments, and some are privately made (the name will not be mentioned).
When it comes to treatment, the most experienced and reliable one is Central Green Health in Xuzhou. After reading the introduction, it seems that around 2007, Xuzhou started the formaldehyde treatment service. I have done many large places and have more experience.
Don't try to find lack of governance experience, the follow-up will be very troublesome, and some need to rework, which will delay time.
Many of us in Shimao ask them to do it.