Since Maiman invented the first ruby laser in 1960, humanity has never ceased to develop lasers and expand their applications. Characteristics such as coherence and high energy density are unique to lasers. It is precisely because of these superior features that lasers have been widely used in many aspects of human life, such as printing, welding, cutting, communication, and storage.
One could say lasers have brought a qualitative leap to human production and life. However, at the same time, lasers also bring many safety issues.
The widespread application of lasers has brought a series of problems, among which safety is the most prominent. Taking the welding and cutting applications in industrial manufacturing as an example, lasers have high power, and the production and processing environment is complex.
Laser production systems have not undergone strict laser safety assessments, and operators lack basic laser safety training. A combination of these factors could potentially cause severe losses to companies or employees, such as personal injuries, laser damage, and destruction of factory facilities.
In general, the issues currently present in laser applications fall into the following categories:
1. Laser devices or products have not undergone strict safety assessments and certifications.
There are beam hazards and non-beam hazards, such as electrical, mechanical, fire, and toxic and harmful substance release.
With the rapid development of laser application technology, many traditional manufacturing industries have introduced laser technology. This brings technological innovation and new momentum to the products and businesses, but many companies are not prepared for the safety certification of laser products.
They are unfamiliar with the harm of lasers, laser safety levels, evaluation standards, and market requirements for laser safety in different countries.
Related reading: Laser Product Safety Levels
This is mainly manifested in the following aspects:
- R&D design and production personnel lack laser work experience.
- The company’s standards do not establish comprehensive laser safety requirements.
- Laser safety protection for personnel and facilities is not in place.
Based on the laser product certification data analysis conducted by TÜV Rheinland between 2015 and 2016, we can understand the seriousness of this issue through the company’s research on laser safety knowledge and initial product laser safety design defects.
- Do not understand the requirements of the Yiguang nameplate and manual
- Lack of understanding of the responsibilities and obligations of invited light product manufacturers
- Easy to Mix Bath IEC and FDA Requirements for Laser Safety Level
- Lack of understanding of laser safety standards, specifications, and requirements
- Security level that cannot be resolved
- Completely unaware of the hazards of avoiding light
- Lack of laser output indication
- Lack of safety interlock device
- Incomplete laser protective casing
- The evaluation criteria are inconsistent with the target market
- Missing laser information in the manual
- The position of the laser warning sign is incorrect and the information is inconsistent
- Missing laser warning signs
If we are unclear about the hazards and safety level requirements of lasers, and the laser safety standards in the Japanese market, it would be difficult to consider all laser safety elements at the beginning of product design and produce products that fully comply with safety standards.
As shown in Figure 2, among all the customers we have served, the statistics of the initial certification defects in the laser safety design of their products are as follows.
In addition, because laser safety is part of product safety assessment, and some regions and countries do not yet have mandatory certification requirements specifically for laser safety, some companies have let their guard down and even ignored the importance of laser safety.
For example, the European Union accepts CE self-declarations, which means that customers can directly claim that their products meet the requirements of EU harmonized standards. Mainland China has not yet made laser safety a mandatory certification requirement.
A considerable number of customers have not strictly conducted safety tests on products exported to Europe, and have only made self-declarations, which has created a great hidden danger for businesses.
2. The final application system of the laser lacks a systematic laser safety assessment.
The application of lasers at the client end often needs to be combined with laser protective screens, optical fibers, robots, exhaust equipment, etc., to form a complex laser processing production system. The systematic safety assessment of these laser processing production systems is often overlooked by companies.
Compared to the safety requirements of a single laser device, the safety assessment of a laser processing production system is much more complex: It not only requires that the design of the laser source meets the requirements of laser safety standards, but also that all possible hazards are prevented when all parts of the system work together.
Not only should the hazards related to the laser beam be considered, but also electrical hazards, mechanical hazards, chemical hazards, ionizing radiation hazards, and the hazards of toxic and harmful substances, etc.
Table 1 lists typical non-beam hazards according to ISO11553-1 “General Safety Requirements for Laser Processing Equipment”.
Table 1: Examples of typical non beam hazards in laser production systems.
| Hazard Type | Examples | Protective Measures | Verification |
| Mechanical Hazards | Misoperation of a robot damaging the laser protective screen, damaging the laser fiber or optical path, resulting in the beam being directed to walls, windows, and other non-working areas. | Protective screen Personnel contact Area Limit interlock | Check interlock circuit Inspect protective screen |
| Electrical Hazards | Primary Hazards: High voltage, energy, large current Secondary Hazards: Ionizing radiation generated by high voltage | Compliance with electrical standards | Testing and Evaluation |
| Functional Safety Vulnerabilities | Incomplete design of emergency stop switches, interlock switches, interlock circuits, gas cylinders, gas valves, etc.: Improper shielding of laser radiation | Improvement Measures | Follow-up Inspection |
| Thermal Hazards | Burns from the processing surface | Restricted Area High temperature warning Protective screen | Testing and Evaluation |
| Vibration | Mechanical arm movement. | Vibration isolation | Testing and Evaluation |
| Noise | Mechanical movement, exhaust system | Sound insulation | Testing and Evaluation |
Table 2 lists toxic substances caused by processing materials or methods according to ISO11553-1 “General Safety Requirements for Laser Processing Equipment”.
Table 2: Toxic substances caused by laser processing materials or methods.
| Material or Processing | Toxic and Harmful Substances | Material or Processing | Toxic and Harmful Substances |
| Ceramic | Aluminium oxide (Alumina), Magnesium calcium, Silicon, Beryllium oxide (highly toxic) | Silicon | Silica or silicon oxide fragments (inhalation can cause silicosis) |
| Plastic | – Low temperature: Hydrocarbons – High temperature: Benzene, PAHs, and polychlorinated biphenyls (like dioxins, furans) – Cyanides, Isocyanates (Polyurethane), Acrylates (PMMA), and Hydrogen – PVC – Polyvinyl chloride | Metal Material | – Toxic: Hexavalent chromium, manganese, copper – Allergenic: Heavy metal dust, zinc, copper – Pneumofibrotic: Beryllium – Carcinogenic: Hexavalent chromium, nickel oxides |
| Cutting | – Heavy metal dust – UV (ultraviolet) radiation – High-intensity visible light radiation | Welding | – Heavy metal dust – UV (ultraviolet) radiation – High-intensity visible light radiation |
| Heat Treatment | – Heavy metal dust – UV (ultraviolet) radiation – High-intensity visible light radiation | Marking | – Heavy metal dust – UV (ultraviolet) radiation – High-intensity visible light radiation |
At the same time, system-level hazard assessments often require comprehensive on-site evaluations and cannot simply be replaced by laser source detection and certification. In our survey, for example, in the field of automotive body manufacturing, currently about 45% of laser production systems have not undergone a thorough safety assessment.
3. Laser industry personnel lack a comprehensive understanding of laser hazards and preventative measures.
In the evaluations we’ve conducted on automotive laser production systems, we often hear operators asking worried questions like, “Is the laser nuclear radiation?” or “Will lasers affect our fertility?”
These somewhat amusing questions reflect a fear of lasers on one hand, and on the other hand, they reveal that companies have not provided their employees with basic laser safety training.
After the laser production system is complete, the company should arrange a series of trainings for employees to understand and familiarize themselves with the following content:
- The hazards of the laser production system and corresponding preventative measures, such as choosing the appropriate laser safety goggles:
- The meaning of laser warning signs;
- Critical safety components like emergency stop, remote control switch, interlock switch;
- Management and operation authorization for high-power lasers;
- Normal operation procedures, troubleshooting procedures, etc.
Only when all employees correctly understand lasers, operate the laser production system accurately, and pay attention to prevent various hazards caused by the laser production system, can the safety of personnel, facilities, and the environment be ensured.
4. Laser processing companies have not established a laser safety officer system, resulting in a lack of systematic laser safety management.
A laser safety officer refers to a person designated by the company who has sufficient laser safety knowledge and is capable of evaluating and controlling laser hazards for the company. The laser safety officer needs to be involved in all activities that may involve laser hazards and manage the laser safety matters within the company. The company needs to incorporate the laser safety officer into the management system and organizational structure, giving them sufficient authority, thereby creating an internal system that values laser safety.
This system is mature in European and American laser manufacturing companies, but unfortunately, many domestic and foreign companies in our country have not established a laser safety officer system. Without a person with specialized knowledge managing overall, it’s impossible to effectively control laser hazards, take preventative measures in time, systematically organize personnel training, and thus fundamentally improve the safety design of laser products.
The issue of laser safety cannot be underestimated. We need to systematically pay attention to laser safety. It’s not only about correctly understanding various laser hazards and spending effort on designing laser products or systems that comply with safety standards, but also about establishing a laser safety officer system within the company as soon as possible, and improving personnel training and operational standards. Only by truly achieving these, can our businesses and personnel continue to develop healthily while ensuring safety.
