We use lasers in all aspects of daily life, but most people think lasers are dangerous and can damage their eyes when they hear about them.But in fact, if you understand the classification of laser safety levels, you will know that lasers are also safe. Lasers exist that can be used to illuminate the eye directly.
Introduction:
Laser safety rating standards measure the risk assessment of laser products to human eyes and skin. The main purpose of these standards is to ensure the safety of people who use laser products.
The internationally widely used laser safety level standard is the IEC60825-1 standard, which divides laser products into four categories of laser safety levels, from low-risk Class1 to high-risk Class4, and each level has several details. Each level has limits on output power or energy density, and also provides corresponding level standards, protection standards, labels and measures to ensure safety during use.
In addition, the US FDA certification agency has also promulgated similar laser safety level standards, which also divide laser products into four categories and several sub-items, from the lowest-risk category I to the highest-risk category IV. Different from the international IEC60825-1 standard, the US FDA standard has its own specific requirements and strict restrictions for each detail.
Of course, we also have our own domestic laser safety grade standard GB 7247.1, which evolved from the internationally widely used laser safety grade standard.
Laser Safety Level Standard
Currently, many countries have their own set of laser safety level standards, such as the laser safety level standard EN 50689:2021, which will be mandatory in Europe in 2024. This is different. Japan’s laser safety level standard is JIS C6802, which We will not discuss the two for now. The three laser safety level standards currently in use are roughly the same, with only some detailed differences. Below we list them in a table for comparison.
| Level | Internationality IEC60825-1 Domestic G8 7247.1 | USA FDA / CDRH （21CFR1040.10） |
| class1 | Optical power <0.5mw, any laser, or laser system containing a laser, will not emit laser light that may cause eye or skin damage during normal use. (Does not apply to higher grade lasers which may be contained when housing is removed during use). | |
| class 1M | A laser that does not cause damage to the eyes or skin unless viewed with optics. | Not defined |
| class 2a | Not defined | A visible laser that is not intended for direct viewing and does not cause any damage to the eyes or skin during operation, based on a maximum exposure time of 1000 seconds. |
| class2 | The optical power is <1mw and cannot emit visible laser light that may cause skin or eye injury within the time period of the human eye’s aversion reaction (0.25 seconds). | |
| class 2M | Unless viewed with optics (telescope), laser safety class 2M will not cause eye or skin damage within the time period of the human eye’s aversion reaction (0.25 seconds). | Not defined |
| class 3a | Not defined | Optical power 1mw to 5mw, the same as Class2, but with the added condition that the beam cannot be directly observed using optical devices (and only for visible light). |
| class 3R | Laser safety level 3R can not exceed 5 times the limit of class 2 (visible light), and can exceed 5 times the limit of class 1 (invisible light). | Not defined |
| class 3b | Optical power 5mw to 500mw, medium power laser (visible or invisible light), contact under direct irradiation beam or mirror (such as mirror) reflection conditions will cause potential harm to the eyes. Except for high-power Class 3b lasers operating in certain special wavelength regions, Class 3b lasers do not cause significant skin hazards under diffuse reflection (scattering). | |
| class4 | Optical power above 500mw, high-power laser (visible to invisible light), contact under direct irradiation or scattering (diffuse reflection) conditions are potentially highly harmful to the eyes and skin. At the same time, fire hazards of processing targets or contact materials must also be considered. (ignition) hazards and attendant potential hazards from radiation penetration. | |
According to the power limit requirements of the laser safety grade standard, we can calculate which grade our laser products meet. Regulatory authorities continuously maintain and update various laser safety grade standards to meet development needs, and these standards include detailed content descriptions that span tens of thousands of words. If you are interested, you can learn more.
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