Two. Introduction, advantages and disadvantages of five indoor air testing methods.
1, cheap hand-held instruments and test paper
2, formaldehyde control company testing
3. Rent a formaldehyde detector for thousands of yuan.
4. Laboratory testing: national standard testing method.
5. GB quantitative colorimetry-GB quantitative formaldehyde self-test box
Conclusion: Non-quantitative hand-held instruments and test paper do not conform to the basic measurement principle. It is suggested to carry out testing according to national standards.
Third, indoor air testing matters needing attention
1, detection standard
2. Temperature
It's time to close the doors and windows.
4. Sampling location
Conclusion: The unqualified test data is meaningless. Even in metrology institutes, environmental protection bureaus and large-scale testing institutions, if the site conditions are not fully prepared, the test results will not have reference significance.
4. Detailed analysis of CMA certification laboratory, CMA reporting process and cost.
1, CMA qualification laboratory classification, CMA qualification laboratory opened by formaldehyde treatment company.
2.CMA reporting process and cost
3. thorny issues in CMA report, "CMA report for sample delivery" and "CMA report for door-to-door sampling"
Conclusion: CMA report is a good choice, but the site conditions must be strictly prepared, otherwise the test results will have no reference significance. In addition, pay attention to cheap and false CMA reports. The CMA report under the real national standard process generally exceeds the budget of most families.
First, the premise of the article:
Everything we say is based on practice and experience.
Five years ago, due to the incident of pregnant female colleagues eating "gutter oil" by mistake, they switched to start a business and worked as a sunshine kitchen platform and food safety traceability system. After a year, there was no improvement, and then I stumbled into the air and drinking water testing industry. This article is based on my four-year entrepreneurial experience in indoor air testing. In the past four years, I personally handled nearly 4,000 sets of air tests in new houses, personally sampled more than 500 sets of new houses, and visited nearly 65,438 households in Dongguan, Shenzhen. We conducted air tests on each new house, carefully investigated the pollution sources, gave practical suggestions, followed up the environmental protection process, and hundreds of owners openly discussed various pollution problems.
We don't take the route of CMA-qualified laboratories, but take the route of testing technology research and development, testing products and environmental protection popular science content, because we find that CMA-qualified laboratories and formaldehyde treatment companies alone can't solve the national environmental protection problems of new house owners. To solve this industry problem, either the national level requires strict environmental protection technology for all kinds of decoration materials, or only the owners of new houses need to improve their detection and processing capabilities. Therefore, it is necessary to innovate testing methods, popularize efficient and accurate testing products, and adopt fair and practical environmental protection skills to let new house owners solve their own problems.
We bees are young, only testing, not managing, not selling managing products, not recommending or commenting on any products, brands or institutions. For odor removal in in addition to formaldehyde, we only say that we think it is feasible to take different measures according to different pollution sources, that is, direct replacement for serious problems and scrubbing, ventilation, drying and high temperature for minor problems.
Usually, when communicating with new house owners, many owners use formaldehyde test paper, the results of hand-held formaldehyde detector and some unprofessional test "small notes" to ask me if my new house is habitable. I have to explain these meaningless testing methods repeatedly every time; In addition, many owners do not understand the principle of industry cost. The first question is whether they have CMA qualification and can produce CMA report. The second question is the price. Let me get this straight. /kloc-it is not enough to test a house with two or three rooms below 0/000 yuan and issue a CMA report. We are a small laboratory, testing technology research and development studio, without CMA qualification, CMA process needs to be rigorous, just to say that the cost of two people coming to the door is higher than the budget of most families (detailed costs will be introduced below). Although we don't have CMA qualification, we have obtained many new utility model patents, and all tests will provide test records to ensure absolute fairness and transparency.
Write this article down this time, so that everyone can have a deeper understanding of the air testing industry and products. Welcome to discuss, but if there is no equivalent experience, please think twice before criticizing.
Introduction, advantages and disadvantages of four indoor air testing methods.
1, a few hundred yuan hand-held formaldehyde detector and test paper;
A few hundred yuan formaldehyde detector does not conform to the measurement principle of formaldehyde detection at all. Passive adsorption test paper can only prove that there is formaldehyde, but it cannot know the concentration of formaldehyde.
A. Counterfeiting by CCTV+Counterfeiting by Shanghai Metrology Institute
Investigation of online celebrity formaldehyde detector: the error is ridiculously high (click the link to enter the news page)
B. Suzhou Municipal Market Supervision Administration
20 formaldehyde detectors, the error is ridiculously high (click the link to enter the news page)
C. Counterfeiting by Shenzhen Consumer Council:
Seven popular formaldehyde detectors, the maximum deviation is 228%! (Click the link to enter the news page)
2, formaldehyde control company testing:
Generally speaking, as long as you have the heart, a little basic knowledge and perfect equipment, you can still measure it roughly. The key is whether the formaldehyde treatment company wants to measure accurately. Some tests are extremely low-cost and can even provide free tests. It is almost impossible to maintain fair testing between the testing fee of several hundred yuan and the management fee of several thousand yuan. But after all, I am engaged in this industry, and it is right to pursue profits. As long as the air after treatment is obviously improved and the test results are true, the company's services are still desirable, but it is best to use other methods or institutions to verify the effect after treatment.
A. Governance companies without laboratories: instruments cannot be calibrated. No matter how good the instrument is, it is useless if it lacks calibration and the detection is unfair. Benzene series and TVOC cannot be accurately measured because the instruments and processes involved are complicated. The same room, three different formaldehyde treatment companies, may be able to get three results, the gap is more than 50%. We have contacted many formaldehyde treatment companies, and they basically don't even know the soap film flowmeter. The flow error of the sampler is frightening. The bead flow is 500ml/min, and the actual flow is 200ml~800ml/min.
B. Governance companies with CMA qualified laboratories: According to national regulations, laboratories with CMA qualifications are not allowed to engage in governance business, but some governance companies set up CMA qualified laboratories in the name of "others" after making money. Left-handed management, right-handed testing, telling the owners that CMA testing institutions are required to issue legal effect reports after management, and this CMA report is also unfair. The characteristic of this institution is that the CMA test report fee will generally not exceed one point in 300 yuan (the market price is generally one point from 600 yuan, and some are more expensive, starting from 3,000 yuan for a house). Of course, this is just a means. If you can finally solve the problem for the owner, why care too much about the process?
3. Rent a ten thousand yuan formaldehyde detector:
Take the machine of Riken in Japan as an example.
Detection principle: photoelectric spectrophotometry is one of the national standard detection methods.
Calibration method: Generally, phenol reagent spectrophotometry is calibrated in the laboratory, so don't cling to the concepts of "ten thousand yuan" and "Japan", no matter how expensive it is, it can only be regarded as a "follower" of phenol reagent spectrophotometry.
Advantages: simple and convenient, if there is routine calibration, the reference value of the test result is enough for ordinary families to use. (If there is a lack of calibration, the gap will be great. A well-known dad commented that the instrument was calibrated once every six months. Send it once every six months, once here and once there, which is a bit long. It is suggested to shorten the calibration time. In addition, please disclose the calibration curve and error of each instrument. )
Disadvantages are: if the operation is not standardized, such as sampling position, many owners put it in the cabinet for measurement, and there is no reasonable preparation temperature and closing time of doors and windows, and the result error will be great; In addition, only formaldehyde can be measured, but not benzene VOC. If formaldehyde reaches the standard, benzene series may seriously exceed the standard. In this case, misleading the owner to live in a new house is tantamount to indirectly hurting the owner's health. While detecting formaldehyde, we should popularize the knowledge of benzene and TVOC with the owners. Testing and courier costs are too high.
4. The most commonly used national standard detection method of formaldehyde: phenol reagent spectrophotometry.
Formaldehyde: the most common national standard detection method, GB/T28204.2 Phenol reagent spectrophotometry. This method is very standard, but it has a certain threshold, because there are too many steps to operate, such as formaldehyde standard solution, instrument curve slope, absorption liquid color solution configuration, reagent configuration, sampling instrument flow calibration, laboratory basic measuring instruments, spectrometer and so on. And it is impossible to operate without a basic laboratory or studio.
Benzene series and VOC: generally gas chromatography, etc. It is more complicated than formaldehyde detection.
Detection steps: The first step of national standard detection is to collect samples, collect samples on the spot, and then analyze the samples in the laboratory to get the results.
Sampling method: There are two sampling methods, the first is self-service sampling, and the second is door-to-door sampling.
Answer: On-site sampling inspection
Advantages: it can help to check the pollution source on site (generally CMA-qualified laboratories will not help to check the pollution source)
Disadvantages: the labor transportation cost of door-to-door sampling is too high, accounting for more than 30%~50% of the detection cost, and the detection area is limited, so it can only detect the surrounding area of the laboratory. If the tester has business such as formaldehyde control, it may be possible to modify the data and promote products and services. If it is a regular CMA organization, the fee should be at least one cent in 500 yuan, starting from 2000 yuan, and the process and test data must be fair, but it may not reflect the real situation on the spot because of insufficient preparation.
Spot check of Burt Bees in Qingyang: At present, it is limited to Shenzhen, Dongguan, Guangzhou, Foshan and other parts of the country, and we will give a fair test. Before the inspection, we will remind the owner to make full preparations, and we will try our best to help find the source of pollution at the inspection site.
B: self-service sampling and testing
Advantages:
A, convenient detection: simple operation, at least one point can be measured.
B, cost saving: saving manpower and transportation costs, and being able to detect most parts of the country.
C, not subject to geographical restrictions: it can detect most parts of the country.
D. Transparent inspection: Blind inspection is more accurate and strict. The experimenter doesn't know where the sample was collected, perhaps in an unpolluted park, so the inspection requirements are more strict.
E. Fairness: There is no opportunity for sales promotion, so as to ensure the fairness of the test.
Disadvantages: reagent aging is affected by temperature, which can be measured in most parts of the country (except remote areas) below 30 degrees. Above 30 degrees, it is generally only supported in the province, and it can only be sampled at close range in summer. In addition, the staff has never been to the site and can't help analyze the pollution source on site, but the pollution source can be determined by shooting videos and the owner describing the smell himself.
Self-sampling inspection of bee cleaning: After thousands of owners' use and experience accumulation, we have updated the third generation sampling instruments and sampling tubes to fully ensure that there is no human error in the inspection process.
5. Our latest detection method: quantitative colorimetry.
National standard quantitative colorimetry-formaldehyde self-test box
Advantages: 200 yuan's self-test box can actually contain a constant current sampler, a modeling flowmeter, a sampling tube and an AR reagent, which can only be done in the laboratory for nearly 10,000 yuan. It is the ultimate tool for personal standard formaldehyde measurement.
A. Process standard: national standard sampling process, quantitative collection and active adsorption shall be implemented.
B, simple operation: there is a video to guide the operation.
C, not subject to geographical restrictions: it can be tested all over the country.
D. fairness: non-interference, absolute fairness.
Disadvantages: There is no spectral reading in the last step, so it is impossible to determine the exact data of the sample, but you can know the approximate data by color comparison. Benzene and TVOC have not been detected, and formaldehyde meets the standard, but the room needs no odor to live in.
Briefly explain the smell of the new house: benzene has the smell of paint and natural water, and the smell of the new house almost belongs to VOC, including the smell of solid wood, benzene, latex, leather goods, textile chemicals and so on. If there is no obvious smell in the new house, then benzene and VOC must meet the standard, but formaldehyde may not meet the standard, because formaldehyde exceeds the standard by two or three times, and most people can't smell it. The average person's sense of smell for formaldehyde ranges from 0.066 to 2.66 (mg/m? ) above (source: Baidu Encyclopedia), formaldehyde is only 0. 1mg/m? (standard GB/T 18883), so the formaldehyde in the indoor air slightly exceeds the standard, and many people can't smell it. To this end, we also did a small experiment, put a beaker with a high concentration of formaldehyde standard solution into the experimental bin, so that the air in the experimental bin contains a certain concentration of formaldehyde. My personal feeling about this smell is that when the formaldehyde concentration in the air of the experimental warehouse (pure formaldehyde, excluding benzene and other odors) is 0.2(mg/m? ), that is, when the value exceeds the standard by twice (GB /T 18883), you can smell a slightly stuffy feeling, a little sweet and greasy, with a little sour feeling. The smell of formaldehyde is very slight, which is easily covered by other smells. In the new house, there are some other smells, such as leather products, latex mattresses, solid wood, especially paint and soft cloth clothes. Therefore, formaldehyde is generally not smelled.
Conclusion: Passive adsorption testing instruments and test paper do not conform to the basic measurement principle, and do not collect samples quantitatively, which is inaccurate. If the self-test tool is calibrated according to the national standard, you can refer to it. The testing of formaldehyde treatment companies is unfair, so you can find them to treat it, but it is best to have your own acceptance method, and don't let them be responsible for the acceptance. The detection methods that can be selected are: the formal CMA organization, the most authoritative, followed by the detection methods and tools that meet the national standards, such as self-sampling detection (which can only be detected in Guangdong Province due to the influence of summer temperature), photoelectric spectrophotometry (which needs to be calibrated in time, if it is calibrated in time, you can refer to it), and our national standard quantitative formaldehyde self-test box (the final colorimetric determination result is not digitized, but it is enough for reference).
Third, indoor air testing matters needing attention
Indoor air testing belongs to dynamic detection, and the preparation conditions will seriously affect the detection data, and the data out of the conditions have no meaning, so we must make strict preparations to get a completely valuable data.
1. Test standard: home, baby, classroom, office, etc. It is recommended to follow the national standard GB/T 18883 (other standards are not recommended) (GB50325 has been updated, and the following figure shows the old data).
Unconditional data is meaningless, please prepare as strictly as possible!
2. Sampling temperature:
Theoretically, the higher the temperature, the more formaldehyde is released. Generally, the detection temperature is 25-6 degrees, which can be referenced all year round, because above 26 degrees, doors and windows are basically opened for ventilation, or the air conditioner is turned on to drop below 26 degrees. When the temperature is lower than 26 degrees, the formaldehyde emission is not more than 26 degrees.
Pay attention to the temperature when measuring formaldehyde in winter and spring;
-If heating or air conditioning is turned on in winter and spring: generally, the heating temperature in winter is about 23 degrees, which is enough; Turn on the air conditioner if it is about 26 degrees, turn on the air conditioner when closing the doors and windows, and turn off the air conditioner after sampling. (Note: Air conditioning is basically internal circulation, so it won't have an impact. But the central air conditioner may have the function of ventilation. If there is ventilation function, the air conditioner can't be turned on, and the air conditioner remote controller can withdraw cash. )
-If heating and air conditioning are not turned on in winter and spring: choose the day with the highest temperature to meet the reference conditions for staying in a new house in winter and spring.
3. Time to close doors and windows: Before collecting samples, the national standard suggested that the time to close doors and windows was about 12 hours, which imitated the relatively long time we lived and slept indoors. If you can't accurately grasp it, there will be a difference of two or three hours. If the gap is too large, for example, when doors and windows are closed for 24 hours, formaldehyde may be released 0%~ 100% more than when doors and windows are closed 12 hours. 0. 15mg/m if the door and window are closed for 24 hours? (The standard value is 0. 1), which is embarrassing. I don't know if it really exceeds the standard. In addition, if it is closed for a long time, it will not exceed the standard, which means it is more environmentally friendly.
4. Sampling location: China only has indoor air quality standards, but furniture, cabinets and drawers have no air control standards. When sampling, it is generally recommended to choose the geometric center of the room or a location close to breathing and convenient for collection.
Conclusion: The unqualified test data is meaningless.
4. Detailed analysis of CMA certification laboratory, CMA reporting process and cost.
CMA qualification is authoritative, because the testing process is the embodiment of national standards. Indoor air testing CMA reports that the current market price ranges from 60 yuan to 3,000 yuan (Taobao has a large number of CMA reports of 100 yuan to 200 yuan, with formaldehyde control companies operating behind them). Why is the difference so big? The focus is on the testing process, whether to follow the national standard!
1, CMA reporting process and cost: Why is a formal CMA report expensive?
A, the cost of human transportation is high: there are many people in the east and west, so you must drive. Double sampling is the basic norm. Supervise each other to remind, operate, record and measure meteorological parameters, with clear division of labor.
B, the analysis cost is high: parallel samples should be collected and blank samples should be left. If the average family measures three points, it is actually necessary to analyze the samples of five points. Test records, quality control requirements and hard rules should be kept for traceability.
C. Long-term data preservation: mandatory, easy to supervise and trace.
D, in addition to testing personnel, there are financial departments, civilian departments, sales departments, site and water and electricity costs, instrument maintenance costs, and reasonable profit demand.
2, CMA qualification laboratory classification
Indoor air testing, a testing institution with CMA qualification, can be divided into four categories:
First, some small cma organizations, especially those from 200 yuan to 300 yuan, are all operated by formaldehyde control companies. The instruments are relatively crude and the tests are unfair. It is generally measured by giving money. The lowest price can be a large number of samples (samples) of 60 yuan (this is a price that Bian Xiao has heard of) and 100 yuan, especially on Taobao, which is relatively rampant and basically equal to. There are some so-called CMA-qualified laboratories on Taobao that can produce CMA reports. Look at the customer's evaluation print, they are still using disposable pre-installed reagents. CMA-certified laboratories don't even have scales to weigh reagents. It is not authoritative at all, but it is illegal.
The second category, a slightly larger environmental monitoring organization, has many projects and relatively accurate detection, but it lives on the orders of the government environmental protection bureau and enterprises, and its instruments are also better. Indoor air testing will be built occasionally. Generally, for at least one point above 600 yuan in first-and second-tier cities, the starting price is 1.5 million (the cost will be explained below). This kind of organization can definitely measure the concentration of formaldehyde on the spot, but it is generally not helpful to check the pollution source. Therefore, before the test, you should prepare for your own on-site conditions. Sometimes the on-site inspection conditions are not fully prepared, such as the plastic film on the brown mat is not torn off, the curtains are not watered, the decoration garbage and the carton of household appliances are not handled properly, and the time for closing the doors and windows is too long or too short, which may lead to great differences in the inspection results. Although the formaldehyde content in the air at that time can be accurately measured, this result may not provide enough reference for living in a new house.
The third category, relatively large environmental protection agencies, such as China Testing and SGS, generally do not accept private orders, or are particularly expensive.
For example, SGS, the world's largest testing and certification body, detects formaldehyde on it. If it tests three rooms, the charge is 2760+ 1537×3=737 1 yuan.
The fourth category, government metrology institutes and other institutions, similar to the second level, can accurately measure the concentration of formaldehyde on the spot, provided that we are prepared. In addition, justice and authority are absolutely enough, and "extra work" is generally not available. Shenzhen Metrology Institute charges 900 yuan one point.
The market is always bad money driving out good money, oriented by customer demand. In order to survive, testing institutions must meet the needs of customers. If customers want to meet the standards, even if the formal institutions don't do it, there will always be inferior testing institutions that can handle it. That is the reality.
3. There is something fishy about CMA report, which contains unfair "CMA sample submission report" and "CMA door-to-door sampling report".
Why does CMA report that 60 yuan can achieve at least one point? Because of this situation, the first is the "CMA report of the samples submitted for inspection", not the "regular CMA report" produced by CMA institutions themselves, but other parties, such as formaldehyde treatment companies, collect samples themselves and send them to CMA laboratories for analysis. Although this is a CMA report, it is completely unrecorded in the sampling process, and its fairness is seriously insufficient, so it is also a deep routine. Second, this CMA organization itself is engaged in formaldehyde treatment business, and the service fee for testing and earning treatment is cheap.
Conclusion: Regular CMA reports are expensive, generally at least 1000 yuan, and those that are too cheap should be polished. In addition, when choosing a regular CMA laboratory, you must carefully prepare the site conditions, otherwise the test results will be the same no matter how much money you spend.