Here, Bian Xiao needs to remind you that in addition to paying attention to the filtration performance of vehicles to pollutants outside the vehicle, the indoor air quality problems caused by volatile organic compounds (VOC) such as formaldehyde and benzene volatilized from vehicle materials and the odor inside the vehicle should arouse your vigilance, because this is a real "invisible killer" to your health. According to statistics, consumers' complaints about the air quality inside the car are increasing year by year. Therefore, when choosing to buy a new car, it is necessary for us to pay enough attention to the air quality indicators in the car to avoid health hazards in the process of use.
How to choose a healthy car with excellent indoor air quality?
For ordinary consumers, there are generally two choices to choose a car with excellent air inside:
First, try the method yourself. Many people sit in cars and smell themselves with their noses. New cars may smell something, but more pollutants are tasteless. In other words, even if you can't smell any pungent smell, it doesn't mean that there is no pollution in the car.
Second, buy a commercially available formaldehyde tester for testing. Convenient, convenient and quantifiable are its advantages. However, the quality of different formaldehyde testers is uneven, and the test results are easily affected by factors such as temperature, humidity and air pressure in the test environment, which makes the results biased. The seemingly scientific formaldehyde tester may also lie.
Therefore, a professional and objective indoor air quality evaluation result is particularly important to help consumers choose "healthy cars". The CCRT evaluation project of China Automobile Evaluation Co., Ltd. has released the indoor air quality evaluation results since 20 18, and has released the evaluation results of 57 hot-selling models so far.
How does "China Automobile Evaluation" evaluate the indoor air quality?
China Automobile Evaluation is the abbreviation of Automobile Evaluation Management Center of China Automobile Center, which is responsible for the operation and management of well-known evaluation projects such as C-NCAP and CCRT. Indoor air quality is an important indicator of CCRT, which is carried out by detecting the concentration of volatile organic compounds (VOC) and the smell inside the car. The specific evaluation methods are as follows:
First, the evaluation of China automobile strictly follows the standards. Sampling environment, sampling methods and equipment, and data analysis methods are specified in the standard Sampling and Determination Methods of Volatile Organic Compounds and Aldehydes and Ketones in Cars (HJ/T 400-2007). For example, before the formal sampling, the vehicle opens the door in the test cabin for 6 hours to fully eliminate the VOC accumulated in the vehicle before the vehicle sampling, and exchange the temperature and humidity between the vehicle environment and the test cabin. Then the vehicle is sealed in a constant temperature and humidity test box 16 hours to volatilize VOC. In addition to the national standard, China Automobile Review has done a lot of work to ensure the fairness, objectivity and professionalism of the evaluation results. For example, all appraisal vehicles are new cars purchased by appraisers as consumers in 4S shops. At the same time, in order to eliminate the influence of different off-line time on VOC concentration, it is stipulated that 28-33 days after the new car is off-line is the same detection time.
Second, there are many kinds of pollutants. In addition to formaldehyde familiar to consumers, China Automobile also tests and evaluates pollutants such as benzene, toluene, xylene, ethylbenzene, styrene, acetaldehyde and acrolein. Among the eight pollutants evaluated, benzene and formaldehyde have been listed as carcinogens by the international cancer organization, which is very toxic. Considering that different pollutants have different effects on consumers' health, the scoring weights of formaldehyde and benzene are improved in the scoring evaluation model.
Third, the test scenarios are rich and fit the actual car use status of consumers. In the "Sampling and Determination Methods of Volatile Organic Compounds and Aldehydes and Ketones in Cars" (HJ/T 400-2007) just mentioned, it is only stipulated to measure the VOC volatilization at normal temperature (25℃ 1℃), but the indoor air quality is really more concerned by consumers when it is hot in summer. On the basis of normal temperature VOC, a high temperature VOC test and evaluation scenario is added to evaluate the indoor air quality. The illumination lamp (400W 50W) was used to simulate sunlight for 4 hours, and the sample was taken in the last half hour. The temperature inside the car can reach about 45℃.
Fourthly, the combination of subjective and objective evaluation makes the evaluation results more accurate. The first three points mentioned just now are all based on objective tests to judge the air quality inside the car. There is also a subjective item in the evaluation of the air quality inside the car-the smell inside the car. The smell inside the car refers to the general name of all kinds of smells inside the car. Most of the smells come from adhesives, plastics, leather, rubber, accessories and decorative materials used in the car. When there is an unpleasant smell in the car, it will have psychological influence and physical harm to people. Although it is a subjective evaluation project, it has high requirements for evaluators, and it is necessary to obtain the "odor evaluator training certificate" issued by domestic authorities. Five certified professional sniffers rated the smell inside the car accurately in turn. In addition to the professional sniffer to evaluate the smell inside the car, China Automobile Evaluation also organized a professional research team to investigate the smell comfort of 400 real users of this model. The evaluation of the smell inside the car is carried out from two dimensions: professional engineers and ordinary consumers.
The fifth step, which is also the most critical step, is how to convert the test results into specific scores of horizontal comparison between models after the test is completed. On the basis of referring to the national standards, the evaluation of China Automobile has made a scoring system according to the data of more than 600 vehicles. Evaluating whether the vehicle meets the national standards is the premise, and selecting the best one on the basis of the premise. It can be said that the scoring system of in-vehicle air quality in China Automobile Evaluation is quite strict. For example, the limit value of formaldehyde concentration in the current national standard is 0. 1mg/m3, and the measured value of formaldehyde in a car is exactly 0. 1mg/m3, so it can only get zero in the evaluation system of China National Automobile Corporation. In order to get full marks in this item, the measured value should be lower than 0.0 1mg/m3. 0.0 1-0. 1mg/m3 is the step score.
Write it at the end
What needs to be reminded here is that the VOC in the car has always existed. The car with high air quality score only shows that its concentration is low, but it is not without it. Therefore, in the process of long-term driving or long-term use, the window should be opened frequently for ventilation, and the external circulation mode should be started in the cold weather in winter to reduce the concentration of pollutants accumulated in the car. This is especially true for the new car you just bought.
In the post-epidemic era, more and more attention will be paid to the health performance of automobiles. China Automobile Evaluation will continue to provide authoritative reference for consumers through more professional and more suitable indoor air quality evaluation. In advance, we will explain the indoor air quality level of the popular models evaluated later, so please continue to pay attention.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.