In today's episode, Dr. Ayers talks with Ken Barat about laser Safety. Ken explains the 4 classes of lasers along with engineering controls for safe use.
The Occupational Safety Leadership Podcast
Episode 167 - Ken Barat - Introduction to Laser Safety
Welcome to the Occupational Safety Leadership Podcast. This is episode 167 with Ken Barat. Today we're going to sit down and talk about lasers. Lasers are one of those things that you hear about. Of course, they're all over the movie. They destroy planets. They do all kinds and meet things out there. They can cut steel. They can etch. They'll kind of come back to the real world and talk about how we use lasers out there in the everyday world. Before that, we get started, Ken. Could you do a little bit of background and tell the audience about yourself, please? Well, sure. David, my pleasure. I was the laser safety officer for Lawrence Berkeley National Lab. The oldest department of energy is basic R&D labs. I was the laser safety officer for National Initiative facility, the people that are doing laser infusion research that about two years ago announced that they had a shot that actually created more energy out than they put in. I've been doing laser safety for, as you can see, with the white beard for 30 years. I do laser safety advising for all suspects. I was the laser safety advisor for the LIGO folks, Gravity Waves, things. I've just recently come back from Hawaii to the Keck Observatory, helping them out with some laser issues. When I do have a quarterly column on laser safety and photonic spectra, I have a number of textbooks written. Just a lot of experience with lasers and at one time, the state of Arizona had an independent agency on radiation, and I was the laser safety group leader for that, so ran the regulatory program for the state of Arizona. I just do a lot of experience with all different type of laser applications, so that's kind of me. Awesome, Ken. Awesome. Before we really get into looking at different particulars and scenarios and all that kind of stuff, could you do just a little background on all the different laser classes out there, please? Sure. The laser classes, when people say what class laser do you have? This is basically a hazard communication device, and the idea is if you may not know much of anything about the laser as far as wavelength or other things, but if you know what class it is, you sort of get an immediate feedback on what type of risk it presents to you. We have the starting on the low end, we have the class one laser that by definition doesn't put out enough power to cause eye or skin injury, and it gets confused all the time with the class one laser product, so that's like if you have a laser printer on your desk, the laser that's inside that, that does the actual work, is a higher class actually because eye injury, but the fact is during normal operation and the key is normal operation, it's all contained, there's no hazard, there's no risk. That's why they're not required to have a laser warning label on the outside of, you know, units like that, and if you now have bought a laser cutting device or work or home crap type of things, cutting, you know, leather, metal, I actually found someone that was cutting chocolate with their, with their, you know, just have to have the imagination. You know, those are class one products, even though the laser inside is considerably higher. So then we have class one M, which is an invisible laser, but it's a large diameter beam. So the beam is so large, that the power of square centimeters below eye hatches. So unless you look at it with some type of collecting optics, it's not a hazard. So you see this in free space communications, where they're setting a laser beam from one building to the other, kind of like line of sight, microwave tower. Then you have class two M, which is the visible version of class one M. Then you've got class two, which low power laser, less than a milliwatt, what it counts on is your eye doesn't like bright light. If someone shine that at you, the feeling is your version response, your body's natural response to bright light, you would turn away in less than a quarter of a second, and you would not have enough energy in your eye to cause permanent damage. So the early laser pointers, when they're all red, were class two devices. Then we have a 3R, which is one to five milliwatts, which is one of all the laser pointers or label that. If we have an advance for your power point and it's got a laser in it, a 3R. Once again, you're safe from momentary viewing, but you wouldn't want to look at the beam through a pair of binoculars, because it would focus the smallest spot. So before we get to 3B, where a laser safety gets to be important, in Europe, there is something called class one C, and the C stands for contact. So there are a lot of home devices you can buy to remove hair, remove wrinkles, that's what they're sold at. But really the power is like class four, it's a higher power. So we don't want people holding a handpiece and waving around this class four laser. So it's engineered so that the handpiece must be in contact with your skin. If it's not in contact with something, it will not fire. So the beam is actually contained. So you have a lot of, you know, those are, like I said, it's not a recognized classification here in the States, maybe, you know, 10 years it will be, but it is what you can find that in Europe on some medical devices there. So once you cross the threshold above 3R, now you're above five milliwatts, your class 3B, which can be visible or invisible, and 3B's got a pretty wide range. It's from five milliwatts to 500 milliwatts to half a watt. And those lasers potentially could cause eye injury. And they're generally not strong enough to do a skin burn, but they definitely can damage your eyes. Once you're past half a watt, you fall into class four, which today has no upper limit. So it can be visible or invisible, so whether it's one watt or 500 watts or 100,000 watts, they're all class four lasers, and those are the ones that since there's no upper limit, they have potential for eye injury, skin burn, can ignite things, you know, they can really be very hazardous, but once again, if I've got a, you know, five, you know, five hundred and fifty nanometer, five hundred and fifty milliwatt laser, yes, it's class four, but it's not the same, you know, risk as a thousand watt, you know, laser. So in that way, there's been a lot of interest in having a higher class, like a class five, and this has been pushed by the folks doing laser weapons development because they've gotten megawatt power or 60, a hundred, five hundred kilowatts of output, and they would like to have a higher classification to designate that type of power. I actually liked 4L, L being lethal, but so far, the ANSI committee has rejected that because their field committee's feeling has been that there's not a unique control measure. You still want to keep people out of the beam, you want to give training, you know, they haven't, they don't feel there's something unique while the people that work on these systems feel, oh, there are definitely unique things about this type of power output, but once again, this is something that will bounce around, and since the ANSI standard only gets renewed every seven to ten years, down the road maybe, but how soon, I don't think anybody really knows, so those are the, you know, the classifications of lasers, you know, I can't say, you know, laser technology has made a quantum leap, I mean, dates back to the 60s, but you know, there was a time if you, you know, had a legacy, you needed a team of grad students to keep it up and running, you know, it's like owning certain type of sports cars and it's in the shop more than it's out on the road, you know, but the, now it's solid state lasers and laser diodes, you know, lasers are being used everywhere, early on, you know, I was new some people that were doing laser dental development, and at first, even though they had systems that would, you know, remove soft tissue gums and do cavity work, the fact was that no dentist wanted to buy it because the support was so intensive. Now that you have a solid state system that you plug and play, you turn it on and beam comes out, they don't need anything else, and it's, you know, it's like the old days with phones, your phone was broken, you didn't fix it, you got a new one, I mean, the price range has dropped to that point, so now you're seeing, you know, dent lasers and dental offices and all sorts of devices that lasers are being used that I've recently been dealing with some people that are doing laser welding, and, you know, which has many advantages over traditional welding techniques, and same thing goes with using lasers to clean graffiti off cement and, you know, clean statues and stuff like that, you don't have hazardous chemicals, you don't have hazardous waste to deal with, but it's a class for a laser and, you know, you're holding it in your hand and the beam is coming out, and all sorts of, you know, what type of safety do I have to provide to the user and those around them, but lasers are everywhere, and there's no, I'm not aware of any area in modern society that doesn't have some laser situation, you know, if you, you have a problem with pigeons on your roof, there's a laser system that will scare them away, you know, and not only is it a roof, but there are laser scare probes where you can buy in a cornfield that will periodically send out a, usually it's a green beam to scare birds away, I mean, it's like everywhere, one of the interesting ones which I know has been developed, but I haven't seen a lot of use is lasers to deflect lightning, you know, basically it's a system that sets up a, so the weather, in a case, you know, the weather issue, you know, or like thunderstorms are coming, it sets out a false like plasma ring or plasma beam, so the lightning goes down that red and hitting your power line. Wow, that is neat. Yeah, I mean, there's some really fantastic, not always things have been adopted or I think fine-tuned enough, but a lot of work's been done on that and actually I just think it'd be, if you're a good salesman, you sell one on the block and affecting the laser, you're lighting to the neighbor's house and then they want to get what affected down the road, so I just think it's, you know, it's going to be there, but lasers are just showing up everywhere today and the issue for laser safety is while we're excited to see laser technology spreading, a lot of times people don't appreciate the hazards because it becomes so commercial. One last example I'll give you is the, you know, the mom-and-pop trophy shop, where you go in and, you know, you they engrave the plate, well, it may not be much of a laser hazard because it's usually a fixed, you know, setup, but what about the fumes that are giving off? You know, most of those are carcinogenic, you know, so how do they ventilate it? Do they ventilate it? You know, so they're commercial products, they're out there for the public, but is safety being, you know, addressed and the thing that I find is people say, well, if it's an improved product, you know, if it's got all the best bells and whistles on the, as a product, well, that means it's safe. Well, a label doesn't keep you safe. Right. So like I said, lasers are everywhere and there's that. So on the thing about, you know, like enclosures, as you'd mentioned, so you can buy these units that will cut out pieces of plastic and like leather and all sorts of things. And they're generally totally enclosed, you put the lid down, you do it. You want to do some marking something, the part comes in, the doors closed, laser fires. But all those systems are pretty much made with the interlock that can be bypassed. Why? Because you may have a workpiece that's bigger than the, you know, the enclosure or you, something that doesn't fit. So now you bypass the interlocks and that probably means you had the enclosure open. Well, do I have to worry about reflections coming out or what issues with that? So even though you may have a class one product, you know, do you appreciate these off normal, I would say, you know, the applications and uses uses. I've certainly been to places where once the device is interlocked, it's never removed. You know, the interlock stays there forever. And all the safety devices are now useless because they've been defeated. So there's sort of the story with all of that. But, you know, like I said, if you've got some type of cabinet system where the machine's not supposed to fire and unless the doors are closed, I mean, that's great. But you know, there's certainly been cases where people have bypassed it or didn't realize that the beam was still on and reached in. I mean, there are issues with that. So there are incidents that are happening, not luckily not a large number of laser actions, but potential is always there. I think that you can also pick up things that have a long-term effect, but you don't really know it. When you kind of think about you, you talked about all the fumes and the exhaust from at the end, you know, I know that the ones that I tackle, you know, we exhaust the whole inside. You know, it goes to a whole series of filters. We shoot it outside afterwards and all that stuff then. Those are a little bit intensive to really go back and make sure, you know, the filters are good, they're changed on a regular basis and all that good stuff. And we have it because we take it serious, but I have talked to a couple of safety folks who, because it counts as a extra, you know, and the person who buys it doesn't really understand that it just counts as extra. So I'm not going to pay for it for extra of course, you know, I'm going to, I'm going to get that laser in, they get it in, fire it a couple of times, and then they figure out like, oh, oh, it's got some fumes to it, it's got some things, things happening to it. Yeah, well, I mean, without a doubt, and even people that, you know, have filters, many times I find, you know, they, they said, oh, the manufacturer says this filter is good for three months, they don't think about the duty cycle of how much you're really using it and how much it gets, you may get clogged up. Yeah, I mean, it's, anytime you talk about an expendable or some extra thing that, you know, doesn't get presented as part of the, part of the sale. I mean, I had a research lab. I once recommended to a user that they get an interlock for the door. And I'd said, hey, you know, this, you know, there are a couple ones out there, this one cost you $1,500 and the guy said, okay, I'll get it. I got like a month later, I get this irate phone call and he says, well, you didn't tell me that not only is there $1,500 to, for the hardware, it costs me $3,000 to have facilities electricians come and install it in my room. And I said, yeah, I have two electricians come in, they charge me, you know, full time for each one. And next thing I know, I've got this huge bill and I said, well, it surprises me too, but that, you know, you got to look at the big picture all the time. Right, right, right. And that's why that I really stress to folks to understand the entire concept first and then really present that, present that package, you know. So like you said, there's a lot of people that they'll buy the, they'll buy it because they want to buy it, but they don't think about all the other costs, you know, and then that'll just snowball into, well, now it's not a real, a real, real, real project anymore because, but if people know the real cost upfront, they seem to be a whole lot easier about things too. And the vendors do a pretty good job of giving you a total package as long as you buy a total package, of course, and not I can buy some cheaper filters here. I can, I can, I can run my own duck work in another way and all that stuff without a doubt. And, you know, you really have to, you have to really work with the salesperson, you have to feel they're, they're being straightforward and, you know, honest with you on what your needs are, and, and all of that, which is why, you know, that, you know, typically the, you know, the smart bar, if you have a choice between a class four device and a class one product, you're going to go because the other thing, you know, the, once you get to three B and four from the standards perspective, you have to have someone responsible for laser safety. Operators have to be trained, you know, their, their sign is there's administrative things you need to, you need to do. And, you know, that becomes something that's another effort involved, you know, training of people and how you're going to go about doing, doing that. So, like I said, once you get to three B and four class lasers, the standards say there are things you need to get, you need to do to have an effective safety program. So right now here in the States, you know, there's, we have federal and state OSHA programs, and while they're responsible for worker safety, they really don't have any regulations on lasers specifically. There are a couple on construction lasers, but they generally consider those to be diminished below any real concern. So, but what OSHA says is that if you want to demonstrate you have a good laser safety program, then you should be following the ANSI standard. So you, you know, we, so we have a very, a number of ANSI standards from for laser use, and that's how you're supposed to base your, your program on. And so if you get, if you get an ocean inspection and they cite you, they cite you under their general duty clause as, you know, is there, is there authorization and say you're not providing a safe work environment because you don't have an LSO, you haven't have an enclosure and things of that nature, and yes, but I will say sometimes I think that the ANSI committee forgets, you know, they like to say that we're just fighting guidance, and they sometimes don't want to acknowledge the fact that their guidance is almost regulatory from a government's perspective. And sometimes things get put in that sound really nice, but they don't think about the burden to the user on what it means to actually, you know, do that and how practical it might be. So cutting a long background in research labs, one of the best models I found for a safety department once was a safety through cooperation, you know, you got to have buy in, have that buy in from your users, I mean, I personally can design a laser safety system for someone that I can guarantee no one will ever be hurt, but I could also guarantee probably no work can be done. So you need to find that balance between the two, and so it's a partnership, laser safety, I think is much different than number of other safety disciplines, you know, if I'm a ventilation specialist, like I'm in, I measure the flow rate, and I'll tell you to put the sash this high or increase the blower, and you may not see me for another year, you know, if laser safety officer, they're supposed to do periodic visits, help you see your controls or help you develop the controls, make sure the controls are being used, you know, they're around more often, I think it is more intensively stuck to me, once again, another underpaid occupation, all I have to say, mm-hmm, mm-hmm, yeah, yeah. So when it comes to lasers, for me, I've only used those cabinet ones, I've been really super, super lucky every place I were that I've been, that I've been able to, well, I hate to say force, but I've been, but I've been, but I've been able to convince folks that we need to have it as a class one product for the operator, you know, and all that kind of stuff then, can you think of any benefits to having a open beam as opposed to a cabinet system? Well, you know, it's, the real thing to me is, is we say, open beams, I have open beam path, well, you know, what, how long is that open beam path? You know, there are, you know, robots on the assembly line that the beam path coming out of the robot arm is, you know, one or two centimeters, you know, so therefore you've got an open beam, but the likelihood of anyone, you know, getting close enough to get in the beam or get a reflection is, is so low, it's almost like getting closer because they're right, can't get close. And you've got other systems where the open beam is, you know, greater distance. And like I just, you know, just mentioned, if I'm doing cleaning with a laser wand of, you know, metal parts, you know, I may be three, four feet away from the metal part and I have an open beam, all that, all that distance. Well, there are a lot more issues involved with involved with that. And so, you know, it varies on what you're doing, you know, it's very interesting thing. The regulatory agent in the UK is now pushing the concept that if you need to wear laser eyewear, that tells us or tells them that your laser safety program has failed, that you cannot interact with things enough. If you have to wear eyewear, it means that you're not programs like your system's not protected enough. So little dramatic, I have, you know, it'd be a long time before the US is ready to go that way, but it is definitely a different approach. But like I said, open these depends what you're doing and, like I said, the operation that you are. But, you know, the only thing you don't mention, you know, there are a lot of, there are a lot of laser systems that when they hit a target, they actually generate ionizing radiation. So that gets me another thing, you know, the people may have to be concerned with. But the usually people that are doing systems like that pretty much already well understand that what's what they're doing and have, you know, other controls for that. But, yeah, so there's those things. And as technology keeps advancing, you know, it's a real challenge for regulatory people and for the standards, because the laser welder, even though generally the beam path is pretty short and the laser cleaning device, those really are outside the general description of lasers in the standards. Because they're thinking more of the traditional type of, you know, type of laser. So as new technologies come along and when the standard only gets done every, you know, seven to ten years, it's very easy for them to be behind. I, you know, have a column showing up, I think it's in the November issue of Botanic Spectre on the issue of laser use in clean rooms, which once again is an environment that typically doesn't fit in the typical laser standard. You know, do you need a warning sign? Do you have visible light? Where do you put it? The whole ergonomic issue of working in clean room clothing, which is much different than the grad student running around in jeans and a t-shirt, you know, type of thing. So we're constantly trying to catch up, but, uh, lasers take the people need to be aware of what's going on and how they want to adapt to it. Mm-hmm. Mm-hmm. Awesome, Ken. Hey, so it looks like we are bumping, bumping up on time. If you could take, take just a couple seconds and let people know how, how, how, that they can find you out there, Ken. So my, I, uh, I'm behind the top. Well, I had a website that got rid of it because no one ever went to it. So basically, if you want to get in touch with me, uh, my email address is laser safety solutions at gmail.com. And, uh, that's my, my email address because when I retired from the Department of Energy, I got a contract to do some training for Los Alamos Laboratory. And, uh, the contract people said, no, you can't say contract is what Ken. We want a company name and more formal and all of this. So, you know, uh, you know, sitting down with a bottle of single mole came up with the title and that's, so my company name is like laser safety solutions, but the company is me. So laser safety solutions at gmail.com is how the best way people can get is my most so unlinked and you can find me there. But, uh, always happy to answer later safety questions. And, uh, if it's a question by email, it happy to do it. It's not like holding your lawyer in the clock starts. Happy to share my experience with, with, with everybody out there. Great, Ken. All right. Great, kid. Thank you. Thank you so much. Um, I didn't have a chance to eat, eat, but ask half of the questions that I had. Uh, so, uh, we'll look at, yeah, get me back on here if, if this was a positive, um, experience for you. So, and, um, with that, we are over with 167 with Ken, uh, Brad Barrett. Uh, I'm sorry, Ken. Thank you so much, Ken. Have a great day. Bye. You too now. Bye. Bye, folks.
In today’s episode, Dr. Ayers talks with Ken Barat about laser Safety. Ken explains the 4 classes of lasers along with engineering controls for safe use.