Exact safety concerns and possible effects of 1W @ 445nm

[Seoul_lasers]

Alright, I feel the need to post this here I think.
I an a previous post I may have indicated that these new $200USD Wickedlaser 445nm "pointers/ aka, laser weapons of mass destruction" were somehow or another toys.
I am not in anyway claiming this, I am playing devils advocate. What I would really like is all the hype to be removed from this issue.

1) I fully support a licencing system for these and anything in class high IIIB- IV. Selling them to just anyone is a BIG NO and dangerous. I totally agree.

2) I want a list of effects scientifically listed for exactly what kind of damages could occur with this kind of laser at this power. NO HYPE, no emotion or suggesting we are all doomed. please.

3) Pictures showing the safety conerns, obviously don't stick it in your face or anyone elses, but if you have to use a (dead) (for disection) cow eye do it and show pics. disect the eye and show any damage or microscope slides showing damage.. whatever.

 

[cmak]

what an active thread

 

[davidgdg]

I did a post on blue-light hazard a while back:
http://laserpointerforums.com/f53/blue-blu-ray-405-safety-blue-light-hazard-38374.html
This was with reference to 405, but is arguably more relevant to 455.

David

 

[Benm]

At 1 watt, you can add 'fire hazard' to the real world safety concerns too... with 200 mW or so its difficult to set anything on fire (except for a match), but at the class-IV level this can become pretty problematic, even with beams not focussed to a pinprick but just focussed to infinity.

The cow eye is a nice idea for a very graphic demonstration, but i doubt it will work with a dead eye. One problem is that a dead eye will not focus to any specific distance, though i suppose the position just after death would be infinity at least until rigor sets in.

One major distiction is that there is no circulation anymore, so no heat is transferred away from the retina at all. For exposures of several seconds this will make a major difference, and result in more dramatic damage than you would see in a living eye. For very short exposures (blink-reflex fast) it should make less of a difference as far as thermal damage is concerned. Photochemical damage would not be observable in a dead eye.

 

[LSRFAQ]

Short time period, burns or permanent damage, possibly even blindness if you hit the right spot, so degraded vision. Degraded color vision for daily exposure.

I. Nominal ocular hazard distance , of some hundreds of feet.
If Wicked's stats are correct, around 700 feet, before you can blink, for Artic Blue.

Based on 1.5 mm diameter, 1.5 milliradian divergence , Skyzan calculates 723 feet.


II. Temporary flashblindness resulting in secondary reaction. Ie your flashblinded and you hit your head tripping over a object or lose control of a vehicle.

Skyzan calculated around 2000++ feet for this, being a possibility.

III. Skin damage hazards. Don't have hard data on this, but if 50 mW burns when barely focused, 1 watt surely will.


IV.This over a long time period, exposure is cumulative, it does not only apply to lasers, but things like white leds, at least the ones consisting of a blue led pumping a yellow phosphor to make white, and things like excessive sun worshiping:

Steve

Some citations:

"The principal retinal hazard resulting from viewing bright light sources is photoretinitis... Only in recent years it has become clear that photoretinitis results from a photochemical injury mechanism following exposure of the retina to shorter wavelengths in the visible spectrum, i.e., violet and blue light... it has been shown that an intense exposure to short-wavelength light (frequently referred to as "blue light") can cause retinal injury... By filtering out short-wavelengths [blue light] from a white-light arc lamp, Ham et al. showed that the risk of photochemical injury to the retina could be enormously reduced."

Guidelines on Limits of Exposure to Broad-Band Incoherent Optical Radiation (0.38 to 3 micro m), The International Commission on Non-Ionizing Radiation Protection. Health Physics 1997; 73(3):539-554.


"Age-related macular degeneration (AMD) is thought to be the result of a lifetime of oxidative insult that results in photoreceptor death within the macula. Increased risk of AMD may result from low levels of lutein and zeaxanthin (macular pigment) in the diet, serum or retina, and excessive exposure to blue light. Through its light-screening capacity and antioxidant activity, macular pigment may reduce photooxidation in the central retina."

Bone RA, Landrum JT, Guerra LH, Ruiz CA. Lutein and Zeaxanthin Dietary Supplements Raise Macular Pigment Density and Serum Concentrations of these Carotenoids in Humans. Journal of Nutrition 2003 Apr;133(4):992

"Visible, non-coherent blue light has a high damage potential. Green light, insharp contrast, does not induce any lesions ... Because sunlight and many high-intensity artificial light sources contain relatively high proportions of blue, and the retina as well as pigment epithelium contain several types of blue-absorbing molecules, the short-wavelength band of the visible spectrum may contribute to the pathogenesis of age-related macular degeneration and amplify some forms of inherited retinal degeneration."

Reme CE, Wenzel A, Grimm G, Iseli HP. Mechanisms of Blue Light-Induced Retinal Degeneration and the Potential Relevance for Age-Related Macular Degeneration and Inherited Retinal Diseases. SLTBR Annual Meeting Abstracts 2003; Abstract 3.5 Chronobiology International 2003;20(6):1186-7.

 

[Seoul_lasers]

thanks guys for filling in this thread. lock it and stick it with all those important threads.

 

[Benm]

I suppose a differentiation between immediate hazard and long-term exposure would be in place here. When long term effects are concerned, no finite result or safe exposure level has been established so far.

Erring on the side of caution seems reasonable to some degree, but its not something to be overdone.

 

[Seoul_lasers]

Blue-light hazard is not going to be one that is verifiable, but since this is a class IV laser obvious immediate hazards exist.
Studies are being conducted about blue-light hazards at current. lots of unknowns.