Recently, medical experts worry that LED blue light will cause damage to the retina, even blindness. This news has attracted a lot of attention from netizens and a large number of forwarded comments on the Internet, and it has also attracted the attention of light source experts. Recently, the Shanghai Municipal Quality Supervision Bureau organized a testing agency to conduct risk monitoring on some LED lighting products, and collected 27 samples from different channels for blue light hazard testing. At the same time, the bureau also invited experts from the medical, university and industry circles to “consult†for the first time, and listened to the opinions of all parties.
Guo Anqi, deputy director of the National Electric Light Source Quality Supervision and Inspection Center (Shanghai), deputy general manager of Shanghai Times Lighting Lighting Inspection Co., Ltd., and chairman of the Shanghai Lighting Society, Yu Anqi conducted a detailed analysis of the LED blue light hazard detection. And published the "LED lighting products Blu-ray hazard detection analysis and blue-blue analysis and recommendations" article. In this article, Yu Anqi mentioned that the effects of blue light hazard and “blue-rich†lighting are not unique to LED lighting products. Some of the previous metal halide lamps and some fluorescent lamps have existed for a long time.
In addition, Yu Anqi emphasized in the article that blue light is an important part of white light, so the theory of filtering out blue light under normal conditions is one-sided. It is correct to choose the illumination component and quality according to human physiological rhythm. In order to avoid the possible adverse effects on human health caused by the use of high color temperature and rich blue LED lighting products, the color temperature of indoor LED lighting products should not exceed 4000K, and the general color rendering index should reach 80 or more. Indoor lighting should avoid the use of LED lighting products with color temperature of 5000K and above. At present, it is completely feasible to promote the technology and cost of low color temperature LED products.
Advances in technology have led to the emergence of a variety of lighting sources that enrich lighting products and meet people's needs while also causing harm to people due to improper use. For example, what is the actual situation of LED blue light hazards that are currently spreading widely? According to the international standard, LED lighting products that are determined to not cause blue light hazards, how will the "blue-rich" illumination light affect people's physiology? At the current stage of LED lighting development, we should have a more in-depth study to make the industry develop healthier.
First, the detection and analysis of blue light hazards
According to the possible blue light hazard of LED products, to understand the blue light hazard of LED lighting products in the market, Shanghai Quality Supervision and Inspection Technology Research Institute/Shanghai Times Light Lighting Electrical Appliance Testing Co., Ltd. conducted a bottoming test on LED lighting products. And related analysis is as follows:
1. Sample source and composition
(1) Sample source
The total number of samples tested was 27, which were from:
-8 samples were purchased from small informal stores;
- 5 samples were purchased from large supermarkets;
-14 samples are test samples for large and medium-sized manufacturers.
(2) sample composition
Of the 27 samples, 8 LED desk lamps, 7 LED spotlights, 9 LED downlights, 1 LED bulb and 2 LED panel lights.
2. Purpose and basis of testing
Detect and evaluate retinal blue light hazards in LED lighting products.
Detection and classification according to the standard: GB/T 20145-2006 Photobiosafety of lamps and lamp systems
Hazard Judgment Document: IECEE CTL (International Electrotechnical Commission - Laboratory Committee) Resolution: DSH 0744
3. Blu-ray hazard level and corresponding requirements
(1) Blu-ray hazard level
According to GB/T 20145-2006 blue retinal hazard can be classified as:
1) No danger (radiation ≤ 100 W·m-2·sr-1): The scientific basis of the non-hazard class is that the lamp does not cause any photobiological hazard under the extreme conditions of this standard;
2) Low risk (Class 1) (radiance ≤ 1 & TImes; 104 W·m-2·sr-1): The lamp does not cause harm under the limitation of normal exposure conditions;
3) Medium hazard (category 2) (radiance ≤ 4 & TImes; 106 W·m-2·sr-1): The lamp does not produce a hazard to the glare and temperature.
4) High risk (Category 3) (radiance) 4 & TImes; 106W·m-2·sr-1): The lamp causes damage in a shorter moment.
(2) Corresponding judgment requirements
According to IECEE CTL Resolution DSH 0744:
1) When the brightness is less than 10000 cd/m2 and only visible light is emitted, it is not necessary to classify the hazard level according to GB/T 20145-2006. It can be classified as non-hazardous and can be used directly. If the brightness is greater than 10000 cd/m2, it should be treated as described in 2) or 3) below.
2) If the manufacturer provides a test report indicating that the radiance of the luminaire does not exceed the non-hazardous category and low risk (Class 1) specified in GB/T 20145-2006, the certification body may accept such an LED luminaire and consider it to be normal. There is no photobiological hazard in the case.
3) If the manufacturer does not provide such a claim, it should be tested in accordance with GB/T 20145-2006, and the test results meet the requirements of 2) above.
4) According to the draft of IEC 62471-2 and IEC 60598-1 8th edition, LED light sources and LED lamps of Class 2 and above have no warning mark and cannot be used directly.
4. Detection data analysis
This test performed a two-state analysis of a product, including:
Perform blue light hazard analysis on the test data of normal LED products;
Perform blue light hazard analysis on the detection data of LED products under abnormal use conditions, that is, remove the front translucent diffuser of the lamp and perform blue light hazard analysis;
(1) Blu-ray hazard analysis of LED products in normal use
The test data of normal use LED products is shown in Table 1.
According to Table 1, the test results of various test samples under normal use conditions are as follows: Among the 27 samples, the blue light hazard of 14 samples is non-hazardous, 13 samples belong to Category 1 hazard, and none of the samples belong to Class 2 Danger.
among them:
-LED table lamp: Among the 8 samples, there are no LED table lamps belonging to Class 2, which can be used safely under normal conditions.
-LED spotlights: All 7 samples belong to Class 1 and can be safely used under normal conditions. One sample color temperature is 100000K, which is not a white LED lighting product that can be used for illumination.
-LED Downlight: Nine samples are classified as non-hazardous.
-LED Bulb: One sample belongs to Class 1 and can be used safely under normal conditions.
- LED panel light: Both samples are non-hazardous.
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