Please take care of yourself, prevention is no.1 - Page 1
Forum section: electronics / general

author: nukie
author_rank: Frequent Contributor
timestamp: November 10, 2011, 12:11:10 am
content: http://www.wellerzerosmog.com/health_risk/index.cfmI have been doing constant soldering without proper filtration and usually little ventilation for the pass 20 years. I am going for a lung function test.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 10, 2011, 12:18:11 am
content: I'd be somewhat suspicious of information provided by someone selling extraction equipment...Interesting that it specifically mentions leadfree, the fumes from which are certainly worse - another reason to stick with leaded.

author: IanB
author_rank: Super Contributor
timestamp: November 10, 2011, 12:51:08 am
content: I usually cough and choke if flux fumes get near my face. Makes it hard to breathe them in. I find a small fan blowing across the bench to waft the fumes away works wonders.

author: ivan747
author_rank: Super Contributor
timestamp: November 10, 2011, 02:03:58 am
content: Quote from: IanB on November 10, 2011, 12:51:08 amThat happens to me when I smell burning wood, specially the oily one they use to light fires quickly (I don't know it's name in english). I love the smell of solder, though.

author: saturation
author_rank: Super Contributor
timestamp: November 10, 2011, 11:15:56 am
content: If you have a well ventilated work space so fumes cannot concentrate, you won't need a fume extractor. At most a fan, pointing to the outdoors.However, if you work in a basement or a closed room like in many industrial workplaces with closed room building controlled ventilation, the cfm many not be high enough, and the total number of workers and soldering high, that clearance of fumes leads to problems.While a fume extractor is helpful, a general room air purifier could work too, particularly one with a HEPA filter:http://www.amazon.com/Honeywell-HHT-011-Compact-Purifier-Permanent/dp/B000N9CPQK

author: comox
author_rank: Regular Contributor
timestamp: November 11, 2011, 09:29:10 am
content: I have a Weller WFE Phttp://www.wellerzerosmog.com/tip_extraction/wfep.cfmfume tip extraction unit and could not imagine soldering without it. The filter unit really works. Fan does rattle slightly now that it is a few years old... You do end up with extra bench clutter with the extraction hose, but I have learned to live with this. As we live in a flat my electronics bench is in our spare bedroom; no garage or out-building unfortunately. Have kids too so don't want them breathing any nasty stuff.

author: slateraptor
author_rank: Frequent Contributor
timestamp: November 11, 2011, 11:42:21 am
content: Quote from: nukie on November 10, 2011, 12:11:10 amThe best of luck on your lung test. I didn't take occupational safety seriously until I started to realize that my hearing was going to shit (working around fighter jets for almost 10 years, both full-time and part-time while in college).But to play devil's advocate...Quote from: mikeselectricstuff on November 10, 2011, 12:18:11 amLeaded solder is a contact hazard; there's no question about that. Not saying that you're one of these people, but I've encountered more than the occasional ignorant tree hugger that firmly believes leadedfumesis the real enemy, as if a soldering station (or any consumer heating device for that matter) can produce the instantaneous heat energy required to invoke a state change from liquid to gas in lead. *facepalm*In general, there's no difference between flux fumes in leaded vs lead-free solder...unless you're dealing with some sort of exotic blend that my limited exposure has never seen. It's all the same rosin. The difference is in concentration of hazardous substances, which becomes exacerbated when soldering in an enclosed, poorly-ventilated environment.No one in their right mind would tell you that you shouldn't BBQ because the gases produced are far more carcinogenic than those produced by burning rosin. The difference is no one in their right mind would BBQ in an enclosed, poorly-ventilated environment since the task in itself is an outdoor, well-ventilated affair.In contrast, soldering is not a task that's typically done outdoors, perhaps largely a consequence of the precision afforded by a workbench. Coupled with the relatively minimal smoke produced (compared to BBQing), it's easy to see how most people would turn a blind a eye towards exercising long-term precautionary measures. It's one of those things where it's not a problem until there's a problem, so to speak, but by then it's already too late.Quote from: saturation on November 10, 2011, 11:15:56 amConcerning room air purifiers as being a a suitable substitute for a purpose-designed fume extractor within an enclosed environment: I think this is misleading in that these purifiers work on the macro scale, reducing the overall concentration within the room over time. This implies that the fumes would have to circulate throughout the room before the filter can effectively perform its job...not to mention some of these commercially available purifiers are nothing more than marketing gimmicks that don't adhere to standards. As a supplement to a bench fume extractor, sure. But as a stand-alone replacement, I think not.Just my two cents on the subject.

author: saturation
author_rank: Super Contributor
timestamp: November 11, 2011, 06:30:42 pm
content: Yes, but if you place the purifier infront of your work area, just as you would a fume extractor, it will suck in the smoke as its produced. Fume extractors work the same way, both for concentrated and ambient room clensing.The biggest difference is the cost of the maintainables, on the Honeywell after your $50, the filters are reusable and self serviceable, so no need to buy new ones.An electronics grade extractor, filters can cost between $30-60 each, and the main unit between $60-300. A key difference is the electornics version use charcoal filters which are better suited for longevity for fume extraction versus a particulate filter, and they are also designed to be ESD safe.http://www.tequipment.net/HakkoFA400-04.htmlA particulate filter could clog up sooner as its finer and doesn't have the surface area of activated charcoal. A true HEPA filter will remove 0.3um size objects, about the size of bacteria, and smoke particles are typically 1um-50um in size. Thus, with heavy duty your air filter will need to be cleaned more often and could be annoying in a factory setting.http://www.engineeringtoolbox.com/particle-sizes-d_934.htmlHowever, if you need a filter for light duty work such as a hobbyist or development lab [ that is you are not soldering daily in a production factory setting], an air purifier could be used, because when you aren't using it for electronics, it can also do double duty as a general lab air cleaner.I personally do not own the Honeywell, but something like it. The fan on HIGH does the job if kept close enough to the work area, and in the summer, I just use a fan to blow smoke out the window.Quote from: slateraptor on November 11, 2011, 11:42:21 am

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 11, 2011, 07:03:21 pm
content: Quote from: from the sitei have this symptom since i cant remember. after tinkering with ee and solder, this symptom got better. so for me, this so called "occupational asthma" is just another marketing trick. and my cigarette fume is far more hazardous than flux fume.ps: when was kid, i enjoyed smelling CO+gas combusted out of motorcycle engine

author: IanB
author_rank: Super Contributor
timestamp: November 11, 2011, 07:48:34 pm
content: Quote from: slateraptor on November 11, 2011, 11:42:21 amI'm not absolutely sure, but because of the poorer wetting and flowing properties of lead-free solder I think they use a more aggressive and more highly activated flux with it. This in turn means the flux will produce more noxious fumes. (The rosin itself is no worse than a pine-scented candle, but the HCl fumes from the flux activators are another thing entirely.)

author: slateraptor
author_rank: Frequent Contributor
timestamp: November 11, 2011, 08:26:13 pm
content: Quote from: saturation on November 11, 2011, 06:30:42 pmI'm not confident that a consumer air filter, HEPA or otherwise, is capable of isolating solder fumes. Superficially, perhaps, but undetectable odor is not a clear indication that contaminants have been properly isolated.I'm certain the charcoal element in fume extractors is comparable to the stuff embedded in military chemical warfare suits. I for one can attest first hand that longevity is not the reason for using charcoal; it's used because it works well at isolating and neutralizing fine particulates (I once stood in a chamber filled with so much tear gas that you couldn't see more than 6 inches in front for 20 minutes without a flinch wearing this suit). Although a hypothetical HEPA chem warfare suit may be a world of comfort (and cleaner to boot) than a charcoal-filled suit, I wouldn't trust it with my life.Besides, that link you gave denotes rosin smoke being between 0.01-1 um. If we assume that this information is correct, then that's an order of magnitude smaller than HEPA spec. But hey, it's your health. *shrug*

author: saturation
author_rank: Super Contributor
timestamp: November 11, 2011, 08:43:54 pm
content: Feel free to use what you feel is best. But in the end, HEPA filters are the best filters and typical in clean rooms, its not the first line choice if you can use less as as it easily clogs as it picks up 'everything' and if you breathe through it, has high air resistance before it even clogs.Carbon is used for 2 reasons: it offers the highest surface area, lowest air resistance but is usually geared to specific gases when used in military or industrial exposure applications.While rosin particles can be small, its often fairly adhesive and will stick to much larger membranes.Maybe this link is better as its specific to the industry.http://www.solder-fume-extraction.com/solderfumetechnology/filtration/index.php

author: nukie
author_rank: Frequent Contributor
timestamp: November 13, 2011, 11:33:26 am
content: Carbon is usually the filter media before HEPA filter in a dual filter design. So I think they go together.

author: saturation
author_rank: Super Contributor
timestamp: November 13, 2011, 12:21:49 pm
content: Yes, usually its a self service filter first, carbon filter and finally HEPA in that sequence, for the best filters. Each layer preserves the next layer until its truly needed. Finally, its proportionate to replacement cost: free [self service filters], costly, costliest.Carbon is preferred for gases, HEPA won't work unless the smoke has particulates, that's the P in HEPA.Quote from: nukie on November 13, 2011, 11:33:26 am

author: seattle
author_rank: Contributor
timestamp: November 13, 2011, 07:06:56 pm
content: Quote from: slateraptor on November 11, 2011, 11:42:21 amLead melts at at 327'C/621'F. If you are soldering at temps above that, isn't lead vapor part of your what you are breathing?

author: slateraptor
author_rank: Frequent Contributor
timestamp: November 13, 2011, 07:29:31 pm
content: Quote from: seattle on November 13, 2011, 07:06:56 pmIf by "soldering at temps above that," you mean in excess of 3180 F, then sure. Otherwise, no.

author: Unknown
author_rank: Unknown
timestamp: November 13, 2011, 07:32:19 pm
content: Look up the difference between melting and boiling. Melting is the phase change from solid to liquid. Evaporation rate is likely extremely low due to the high density and high mass number of lead.

author: IanB
author_rank: Super Contributor
timestamp: November 13, 2011, 08:06:26 pm
content: Quote from: seattle on November 13, 2011, 07:06:56 pmThe vapor pressure of lead at typical soldering temperatures of around 650 K is less than 1e-10 atmospheres. So the lead vapor concentration in the air above the solder would be 0.1 ppb by volume, and once diluted in the air currents of the room would be undetectable.There is essentially no hazard from metal vapor in normal home soldering procedures.

author: seattle
author_rank: Contributor
timestamp: November 14, 2011, 10:14:20 am
content: Alm, as I'm sure you know, anytime something is in a liquid state it is giving off vapor, and the rate increases as temperature rises. That is why water evaporates well below it's boiling point. I think Ian's number could be an order of magnitude higher on common soldering equipment, but it's still extremely low. I've never used an precaution soldering and see no need to change now.

author: Unknown
author_rank: Unknown
timestamp: November 14, 2011, 09:49:39 pm
content: Quote from: seattle on November 14, 2011, 10:14:20 amAnd anytime something is in a solid state below its triple point it is giving of gas by sublimation (think freeze drying), the question is just if it's a significant amount. In the case of boiling this is clearly the case, but the temperature is well below boiling point at ambient pressure, so that leaves evaporation. As stated, evaporation of lead is extremely unfavorable due to its physical properties (and so is sublimation). I haven't done the math, but Ian's number sounds plausible. I wonder why you expect the number to be off by a number of magnitude. Do you expect the temperature to be a factor exp(10) higher? The evaporation enthalpy to be a factor exp(10) higher?

author: IanB
author_rank: Super Contributor
timestamp: November 14, 2011, 09:56:56 pm
content: According to the chart I looked at (http://www.powerstream.com/vapor-pressure.htm), the vapor pressure of lead increases ten-fold with a temperature increase of 20-30 K. Which is a good argument for keeping your iron temperature as low as reasonably practical.

author: Unknown
author_rank: Unknown
timestamp: November 14, 2011, 10:45:34 pm
content: You're correct, the P(T) curve is much steeper around soldering temperatures than my estimate. Note that this is the equilibrium condition in a closed system. You're very unlikely to approach equilibrium conditions unless your lab is very badly ventilated, good ventilation is important anyway because of the flux vapors, since flux does boil at typical soldering temperatures.The amount of lead per m^3 assuming equilibrium conditions at 650K is about 0.4 ug. Threshold limit value for occupational exposure all day, every day is50 ug/m^3. So you're still about three orders of magnitude off even in a completely enclosed space without any ventilation.