What risk reduction? What is testing and certification really about? The basics are that products must be safe not be harmful to human, animals and the environment. This is required by the directives and is a basic starting point for our society. Does that mean that we want to know all details, do we really need to have a detailed check on everything? Maybe yes maybe no?
According to the dictionary risk means: exposure to the chance of injury or loss; a hazard or dangerous chance. So it does not say anything about what actually is considered a risk, it basically defines that a risk is something you can be exposed to and that that could result in injury or loss.
Lets have a better look at this when looking at and evaluating lighting. There are many hazards that are directly related to safety. Many we know of. It is clear that when you touch a 230 V power line it will give you an electric shock. It could kill you if the conditions are right (or wrong depends on how you want to look at it). But there are more and more risks that are being found that have not such a clear effect.
Currently due to the change in the lighting industry, many people are taking a renewed look at lighting and new risk or lets call them possible risks are revealed. Not only that, also new possibilities are found as well. For example the negative effects of blue light but also the positive ones. So many new effects are discovered in the recent years. This helps us to make better lighting but it also introduces new risk management issues.
In the past a test of Luminaire was mainly electrical safety. Later EMC was added and than Chemicals (RoHS) was added. These are all issues that affect the health and safety of humans, animals and the environment. More and more issues are added and I do not see the end of it at the moment.
So how to manage the risks. You can do that in many ways. You can simply decide to measure everything and based on all that evidence you know what the risks are and you can market the product. But is that really true? Can you really test everything and decide upon if the product ‘s safe. In my opinion that is utopia. It is not possible since we do not actually know all effects of lighting on the environment en the human body.
A example of something I recently saw during a convention. A scientific research is being done on the effects of lighting in the environment. We are lighting up street and much more and polluting the environment with light where it never was in the past. The scientist are doing research in animal behavior in area’s that are suddenly lit up by for example a street light. It showed that the activity of the small insects that are living in the forested area changed. The insects that are living in the dark area are different species than those that are living in the lit up area. Is that a problem? That remains to be seen, there where no final conclusions yet.
So we should focus on the things we actually know? Maybe we should also keep track of research as it is going. For example there are several studies now showing the adverse effects on humans when PWM dimming is used. If the frequency is to low humans will have strong effects in the short run. I always get very annoyed when I am in a local DIY shop where they have MHN lighting. It is conventional and you can see it flickering. I am not that young anymore and can clearly see this. When the frequency becomes higher the effects will be less. But it is also known that age is having an effect on the response of you eye. When your older it becomes somewhat slower and you are not able to see it anymore. For me the 50 Hz light are clearly visible but how will that be for a baby? Will a baby be able to see much higher frequencies?
So making a nightlight based on simple rectifier technologie might not be the best thing to do if you want this to be used on in a child’s room. We can see the short term effects but on the long run we do not have a clue of what really is happening. So is PWM a wise choice? Lets be clear that when using PWM you need to make sure that the environment you put it in is suitable for it. In a machine shop this is not a good idea. Due to the stroboscopic effect machine can look like they are not running while in fact they are so that would introduce another hazard.
So to conclude this blog I would say that it is very necessary to keep track on developments in science so that you know what is actually going on. Do not panic when there is a new discovery, it needs to be proven first and many times media pick things up and make it into a big story and later it is not as bad as everybody thought it would be. Always get your info from several sources and decide based upon that. The further we get in science the more difficult things will get. If you do not keep yourself informed you might end up having problems that you never wanted.