Dust, toxicity, and shop hazards

Phil705

Phil705

Basic Member
Joined
Aug 23, 2007
Messages
364
I am not a toxicologist or lung specialist, but I have had a belly full of experience in dealing with toxic substances in trying to clean them up. If there is someone with more creditentials, please, please weigh in and help keep all of this in perspective or provide corrections.

Sometimes people use the word toxic a bit loosely.

Toxicity means a substance that causes death, disease, cancer, behavioral abnormalities, genetic mutations, or reproductive abnormalities. Toxic substances need a PATHWAY into the body (breathing it, skin absorption, eating or drinking etc.) at a DOSE that is harmful. The dose can be accumulative with some substances. Since we aren't Nazis and we don't experiment on humans (much), most of the dose data come from extrapolating animal data. That, plus a lot of assumptions that should leave a bit of cushion for human consumption, but it is always good to be conservative.

Some of the wood and plastics we use in handles may be a lung irritant or allergin to some people, but may or may not be toxic. Spun glass insulation, for example, is an irritant to most people, but has never been proven to be toxic. If our handle materials are really highly toxic, we probably shouldn't be using them, or only use them in a highly controlled environment. OSHA should have a Materials Safety Data Sheet on most hazardous materials. (As much as we like to bad-mouth OSHA, the data sheets can be pretty helpful.)

That said, it is not a bad idea to consider most of our dust from metals, wood, plastic, etc. as harmful, especially the particles in the 1-10 micron range which go deep into the lungs. So wear those masks and/or capture the dust.

But while we are at it, let's think about the solvents, adhesives, and acids around the shop. Read and heed the label warnings. And watch out for the dust and metals we take back into the house on our clothing and shoes to our pets and family. And dispose of chemicals properly, even if it costs a bit more.

Thanks

Phil705
Winthrop WA
 
I'm not overly careful about 'shop' stuff, but I believe many wood dust and abrasives components are carcinogenic and not just irritants. It may also be helpful to have dust masks that work well below one micron.

Just thoughts, Craig
 
Just to play semantics, if something that is toxic causes disease by definition, and silicosis is a disease, and certain irritants that create scarring in the lungs cause silicosis (or other diseases for that matter), then aren't the irritants toxic to us? :D

--nathan
 
I used the word "toxic" yesterday when referring to formaldehyde. Is that okay?
 
Toxic can pertain to even the poluted air we breath in big citys . Right now in Kamloops Canada the forest fire smoke is so thick you cant see a city block . That is toxic and some people with breathing problems like asthma can die. I brought up this topic of toxic dust as ive because ive been poisioned several times and have silicosis of the lungs after breathing dust from crushed rock [gravel ] for 25 years not knowing it could hurt me . That why I need to know what is and or isnt really bad to breath after loosing 30 % of my lung volume. kellyw
 
I am not sure what industry phil is in but it sounds like he digs in the same piles I do, I clean up toxic sites. Within the industry there are numerous definitions and long lists of chemicals with PEL , permissible exposure levels, and many others. I see regs from OSHA, EPA, and many local and state agencies (California, no stone unturned)..

To clear the fog.. this stuff is bad for you.. dont breath it. Each person will react to every compound differently and that is something you cannot put on a list. We as knifemakers have the opportunity to expose ourselves and families to a wide variety of chemicals and hazards completely unregulated. The posts on the forum say it all, good ventilation, good protection and common sence and we will all have fun.

Just on a note, I dont think the gasses released are much of a hazard compared to the dust, gasses must be adsorbed over long periods of time, please protect yourself and use proper ventilation and masks. The dust however just gets worse over time, it continues to collect in our lungs and we add toxin on top of toxin. Please wear the best dust protection possible and use a dust collection system. Then we add that fire smoke on top.

good luck ever one
 
How much steel dust would one have to breath in before danger of silicosis? Someone that only makes a couple knives a month with no respirator but decent ventilation. How much should he worry?
 
Silicosis comes from silica, not steel. Silica is found in the abrasives, which break down as you grind your blade, and it is found in the various things people use to line forges with. How much you should worry about exposure depends on a lot of factors, like your overall lung health, whether or not you smoke, how much dust you breathe while you work, how polluted the air is where you are, etc.

But seriously, a box of N95 rated paper welding respirators (flame retardant) is less than $20, a half mask respirator with HEPA cartridges is less than $75. Why worry at all?
 
True, silicosis comes from silica. I was thinking along the lines of desert ironwood in my previous post which has a high silica content. However, any chronically breathed dust/irritant can also possibly lead to pulmonary fibrosis just as easily.

It's just not worth it. Who's to say you won't sensitize to something you're working with and develop an acute inflammation with airway restriction. Believe me, I've had a really bad case of bronchitis that started after working with micarta. I'm not a fulltime maker. At that time, I was working on a handful of knives and the cheap filter 1/2 mask I was using wasn't really helping me at all. It took me several months to get over it, and at its peak I was experiencing laryngial spasms that caused my airway to completely close. All the way. No air in, period. And these spasms most commonly occured at the END of a coughing fit when there was no air in the lungs. I can tell you that not being able to breath at all for 20-30 seconds at the end of a coughing fit is enough to scare the piss out of you. The first time it happened I had just woken up and had a coughing fit. I contemplated calling 911 but knew I couldn't utter a sound and would pass out within the next minute. Luckily, as I made myself calm down, the spasm eased and I was able to take a breath. It sounded horrible as I screeched the breath in (almost a backwards moan). These spasms happened 4-5 times a day for about a week before letting up.

After that, I bought a real North 1/2 mask with full on multi-gas/OV/formaldehyde/etc/etc cartridges, and I wear it when working anything on powered equipment and even after until I leave the shop. The only time I don't wear it is if I am returning to the shop after several days when the air has settled, and even then, I wear it if I'm in for an extended period. That's one of the reasons I got the Breathe Easy system, as I'm expecting it to be more comfortable for longer work periods (though I'm sure it will be ackward at first and I'll have to get used to the extra weight). I've been having more shortness of breath lately (though I know it's from being out of shape, gaining some weight, and some GI problems), and I just want to protect what I've got.

Spend a few bucks on a good 1/2 mask, make sure it seals up, get the proper cartridges, and WEAR IT when grinding. No, it's not the most comfortable thing in the world, but your lungs are worth it, and transplants are no picnic. If you get a North mask, I even have a set of brand new multi-purpose cartridges I'll send you at no cost.

I'll step off the box now. Sorry for the lecture.

--nathan
 
anything is better than nothing but buy a good charcoal mask and your set. One of the worst things to breath is a rock dust called diamond rock simular to granite the dust is real hard on your lungs . Most rail roaders on ballist crews have silicosus ofr one form or another whether they know it or not. They now dump rock with remote control trains to eliminate the dangers. some time.
 
How much steel dust would one have to breath in before danger

Like clint eastwood said "Do you feel lucky". its not one activity for most of us unless we are working in a hazardous atmosphere like loading bags of asbestos. Its the sum of our life activities. Steel dust while not a toxin is in the catagory of not good and will go into you lungs and add to all the other ____ you have put there. Now the question is will be be dead before the doctor wheels in the Oxygen bottle and tells you to keep this with you at all times.

If you smoke plan on taking the oxygen bottle with you, since you have added a daily forest fire to you lungs as well as steel.

The next question should be how much should I spend to prevent this, Clint has the answere, "Do you feel lucky" If you live in clean air, dont smoke and otherwise abuse you lungs and have a healthy immune systems a cheap dust mask may work, but maybe not, until the doc walks in we wont know. A dust control system and good mask start at $200, small investment for life.
 
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I used to own an enviromental testing labrotory. I was the microscopist (one who uses a microscope) and we specialized in airborne dust. Permissable exposure limits can be false as there is time weighted average that comes into play. In other words, the amount of time of exposure. Not to go into a long explanation on the math used to come up with the PEL, let me tell you my experience with air testing in my shop. I conducted many test using polorized light microscopy with a Walton greticle that measured in microns the dust that was in the air. These test were performed during heavy grinding, 10 minutes after grinding and knowing I have a large exhaust fan at one side of the shop that pulls air out. The first teat was on grinding steel. Was noted that there was little particulate below the 5 micron size but quite a lot above. Was wearing the test media on my neck at time of test. Ground for about 90 minutes with heavy removal to fine sanding. In other words, wear that respirator when grinding. The test that was performed 10 minutes later was a 90 minute test and showed very little particulate matter. This being due to 2 facts. The air movement but more important was the weight of the material. It drops to the floor. Now when the test for handle material such as wood, bone, stag it was very different. Lots of particulate in the air and clouded the filter media used for the test that was placed under the scope. Also tested when using the buffer and it was off of the map in high particles. In other words, wear that mask when grinding or buffing. One note, it took longer for the air to clear after buffing. and using an angle grinder when grinding scale off of forged steel it was very very high in particles in the air but was clear after about 30 minutes. Now these test were done in my shop and could be different in yours. The key thing is to create a negative air pressure IE exhaust the air in the shop. Also note that when buying a respirator, check and see how many microns it goes down to and learn how to check for proper fit because if it isnt fitting right, might as well not wear one. Hope this is helpful.
 
I use one of those filtration systems mounted on the ceiling to clear the air in the shop. The mask I use is a disposable made by Moldex model 2700 n95, I get them from Enco for around 10 for $30.00 . These have a little foam rubber nose ridge and hot air vent. These are the only disposable mask that wont fog up my glasses, and are still comfortable. The charcoal masks are what I started with but were awkward, my safety glasses didn't fit right and I couldn't see my grinding. Since I couldn't see, guess what the mask came off and the black boogers were back.
A friend of mine in his late 60's, also a knifemaker, has been grinding stainless for years without a mask. It has finally caught up with him. I won't go into details but it has taught me the importance of ALWAYS WEAR A MASK! The chromium from stainless does not come out of your lungs once it's in there.

Mike Quesenberry
ABS Journeyman

www.quesenberryknives.com
 
Dan, the particulate testing you did in your shop is most interesting! Thank you for sharing it.
 
Patrickknives said:
How much steel dust would one have to breath in before danger
Click to expand...

I know a couple of fellas that worked polishing, grinding and buffing, one for 30 years and one for 40 years with minimal or no mask whatsoever. The 40 year guy, I don't remember ever seeing him wear a mask and he just retired last year with no apparent ill effects; the 30 year guy finally started wearing a N95 rated mask a few years ago and he is in apparent good health.

for the 12 or so years that I was grinding, polishing or buffing I always wore at least a high quality N95 rated mask (there are some poor quality ones on the market these days) When I got more into polishing and especially buffing I started wearing a respirator because buffing some materials like motorcycle brake rotors would cause high temps in the metal and that caused the buffing compound to smoke and pretty much immediately made me sick.

The smell from the greaseless compounds smells like dogshit to me and it sticks in my nostrils for quite some time so I just wore the respirator for the full 8 hour shift and loved being rid of that smell.

I would also cut out pieces of the N95 mask as well as a layer of the really thin paper 'debris' mask as the outer layer and put it under the outer cover of the respirator cartridge to help extend the life of the cartridge. I would regularly take out the paper filters and either whack the dust out of them or replace as necessary. (hope that makes sense.)

I found these strange N95 rated masks without a valve, they are impregnated with carbon and I was amazed at how I could not smell the wood I was grinding while wearing the mask.

I should note that the dust collection systems in the shop are fairly substantial. The inlet duct to the collector is about 18" IIRC.
 
I also was certified to give training on mask. The mask you guys are wearing give very little protection (N95) for particulate in the micron range of 10 and less. Actually it was outlawed for use in the asbestos industry years ago. If you read the info on it ( http://www.professionalequipment.com/3m dust mask/related.html ) it even says reduces particulate matter. I have to say, the better the mask the better the protection. These little mask just dont cut it. Remember, it is the small fibers that cause the problem. On thing science has not been able to figure out is that 2 guys can have the same exposure , one dies the other does not. My recomendation is a good half face like this one http://www.professionalequipment.co...rator-medium-3m-6200dd/half-mask-respirators/ with cartridges like this http://www.professionalequipment.co...te-filter-pack-7580p100/north-safety-filters/ I know they are not the most comfertable but will provide the protection. The ones like n95 are crap. Just my 20 years experience in the environmental business 2 cents.
 
I agree with dan and another thing to consider with a good mask (I think I have the same one as you dan) is easier to breath with because it has better valves and bigger filter area, I had another and it was just too difficult to pull air through so I got a new one.

If anyone doubts the need for breathing and EYE protection please see JT's post (I am glad he realized his mistake) on his KMG Clone build. Watch the sparks being tossed back at him. Just one hot particle in the eye will send you to the hospital in more pain than you think is possible.
 
Nathan and Patrick, good mask. Didnt mean to sound to negative but am just used to being hard on folks because it is for there on good.
 
I always wear safety glasses while grinding, but I got tired of taking hot sparks to the neck and forehead, so I cobled together a makeshift "shield" out of scrap weld steel and mounted it to my tension arm on my KMG so it sits just in front of my tensioner pulley. It blocks the sparks that catch a ride around on the belt get thrown directly at you as the belt passes over the tensioner pulley. Cost all of $0 dollars, and it works pretty well.

Now I only take sparks to the belly and hands :). Another good case for a good fitting welding apron.

--nathan
 
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