EEVblog #1305 - HEPA Solder Fume Extractor

[lfldp]

Unless you set your iron way to hot the lead won't boil and thus emit no gas. Also you are supposed to solder mostly lead-free nowadays. IOW: having lead gas (and tin gas as well) in the soldering fumes is highly unlikely to put it mildly.

i solder with lead-free for few years but i dont like it , in short i searching solution to back to leadded soldering but secure myself against lead gas

this about what you write could be truth about lead gas isnt emited in 100% in soldering temperatures but for sure in some of % it exist
you can do simply test by inhalling leadded tin vs lead-free one the main difference you fell would be metallic taste in mouth caused by leadded tin this is the signall about youre inhalling lead gas . with lead-free tin you wouldnt fell it and btw. there many other health symptoms from lead gas but some people doesnt fell it can solder many hours but some others would fell its deffects in beetwen few minutes so you know

And btw. this 20 year old information about lead doesnt evaporate in soldering temperatures is misleadded information from some of solder fume extractors manufactures such as HAKKO coz in reality they granulated carbon filters which costs big money can maybe absorb no more than 5% of lead gas and more than 25% of formaldhyde etc. vapours from fluxes

And as if you have in plan to buy one of these extractors i dont recommend you waisting even 10 euro for hakko fa-430 unit , better if you choose instead of it chinese waterun f6002D because except standard activated carbon it use catalitic impregnated carbon which is directed to clean air from flux fumes (smallest particles) and cost small money also have filters very cheap by comparing to this hakko crap

and btw what is more whorse about hakko fa430 about if it has just granulated usuall carbon it will not stand so long you will contaminate it very fast by formaldehyde fumes and this carbon is cheapest one from market !

in different case scenario if fume extractor uses one of impregnated carbons or alumin balls with kmno4 theyre directed to flux smallest particles then it will stand very long untill you contaminate it , simply example there is catalitic carbon implemented in waterun extractors

these impregnated carbons and alumina balls are much more expensiff than usuall carbon , now compare price for waterun filters and hakko fa430 filters

Kingsom KS-180 presented there by Dave is one of another chinese fume absorbers but that one looks like have only impregnated carbon foam so i think it isnt sufficient to clean flux fumes at all , some of waterun models have filters like that too but the model F6002D i can confirm it have catalitic carbon inside

also some other chinese clones like bashoshisan they use another media type - moleculelar sieve , about this you should watch out because molecular sieves except filtering flux gas they are mostly irritant when inhalled ! the sieve is cheap alternative to alumina balls impregnated with kmno4 i think better than molecular sieve is catalitic carbon because it doesnt irritiate when inhalled

in short we should have on sticker when buying any of this filters what kind of filtration media is inside it !!! - do i have right or not ? 
if someone is paying big money for this units he should know about is they use kmno4 or molecular sieves

[SilverSolder]

The boiling point of lead is 1749°C.

How much lead gas are we going to see when soldering around 300°C?

[SilverSolder]

It's already well established that there are traces of lead in the air when soldering  [...]

I did not know that.  Is there any references for that where I can learn more about it?

Of course, we all learned in school that every liquid has a vapour pressure above it, even if it is not boiling.  So theoretically, I can accept that the same can be true for a liquid metal...   but one thing is theory, another is measured real world behaviour?  I would expec the vapour pressure of a liquid metal to be vanishingly small.

[SilverSolder]

I did some reading, and it seems the rosin flux smoke is not good for you either, as well as the risk of lead content in the smoke due to the presence of lead oxides on the surface of the solder.   Lead free solder smoke is nearly as bad...   soldering for 15 mins exposes you to a whole day's allowance for several compounds.

Bottom line, an extractor is important for your health if you are doing more than very minimal soldering...

[lfldp]

I did some reading, and it seems the rosin flux smoke is not good for you either, as well as the risk of lead content in the smoke due to the presence of lead oxides on the surface of the solder.   Lead free solder smoke is nearly as bad...   soldering for 15 mins exposes you to a whole day's allowance for several compounds.

Bottom line, an extractor is important for your health if you are doing more than very minimal soldering...

Is there any references for that where I can learn more about it?

hehe there isnt yet because solder fume extractors and hepa lobby doesnt wanna tells you the truth , all this filtration units are signed as they remove up to 99,999% 0,3um dust particles while this dust inst exactly what is damage yours health

i did started with solder fume filters 5 year ago diy versions for past these years i did many experiments with them - and in short i can say about what is the most important to clean from soldering process:

- small particles of gas (formaldehydes toulenes phenols acids) + lead gas (not easy to clean by standard activated carbon)
-large paticles of dust ! -easy to clean by low MERV dust class filters F7 - F9

the hepa in these units in basic reality is just because "it is" this filters remove very small particles of dust which in these manufactory menanings are the most important particles to clean because they going to yours bloodstream and doing whorst of deffects "or can do in future" but this is absolutely no truth and if we meaning there soldering process filtration and whats is exactly damaging you i list there:

-lead gas (not dust !)  cause symtopms like fevers metallic taste in mouth memory loss problems with concentration the lead particles have 0,2um - 0,5um wheres part is dust and other part is gas , if you wherent very allergic like me you propably wont fell  these deffects from lead soldering process but this gas really exist i did many experiments on carbon filters i mentioned about this in previous posts

all of these symptoms comming from lead gas , then where the hell is the "whorst" killing microparticles of dust cleaned by hepa ?! - just in hepa lobby fairy tales

-large particles of dust from solder cause usually cough (easy to clean by cheap F7 - F9 prefilters)

all above mentioned smallest particles of gas are hard to clean with standard activated carbons , they need speciall impregnated carbons with oxidisers or activated alumina threatted by kmno4 oxidiser - all these vapours of fluxes need this except suposedly lead gas

as about lead gas i found certain informations from google about what kind of carbon use municipal waste manufactories for clean heavy metals they use active cokes and what is so funny these active cokes are much more cheaper than activated carbon , while kmno4 alumina is much more expensiff

i am working on new filters these will include alumina kmno4 + activated carbon + active cokes they will be very silent by comparable to commerciall extractors + sucking less power + have better filters and soon on this forum i show my new project (but before that ill also check about is alumina kmno4 could remove lead gas effectivelly) and write there results

oh and i forget there about most important microparticles to clean - cleaned by hepa filters , in these lobby stories whats they cause or "could cause" in future is basically nothing !!! go search in google certain posts on HVAC forums about hepa filtration reality "its been confirmed about large particle dust cause much more health problems than smaller particles <0,3um" these smaller particles which can be absorbed by hepa could cause maybe 10 - 15 % symptoms by comapring to large dust particles and they offcourse "could" in future

i solder by using gas + dust filters except hepa for many year and i never fell any microparticles problems nor didnt fell any deffects after few years

in future means about - maybe i will die on another health issuess untill i even start felling deffects from <0,3um dust microparticles

and btw. i forget to add some of high-end commerciall filters have also included alumina balls threatted by kmno4 to use for laser fumes extraction because plastic or pvc are also small (part of gas) particles and activated carbon isnt enough to catch them all and clean

btw2 the hakko FA430 have less carbon than weller zero smog and thats why zero smog is better - in short nope.. the difference is as follow:

hakko FA430 have just activated granular carbon and can absorb only odours (and maybe 10 - 15% of small flux particles) while the weller zero smog uses pelletised carbon + pelletised carbon impregnated by kmno4 potassium permagnate known as puratex purafil also alumina balls uses same oxidiser and could remove all flux vapours (depending on how much of imregnated media contains these filters)

kmno4 is not easy to buy in small ammount across europe but easy to find+buy from china sellers

[lfldp]

some of more informations from me

the chipquick smd291 flux and suposedly 491 is the one from many which doesnt need kmno4 to clean its vapours

its fumes can be easy cleaned by 1 - 2kg granular activated carbon , but however you will still facing problem with formaldehydes from solder tin and for this need oxidiser kmno4

the other flux i test (many of them i did test) all of them need oxidiser media such as alumina with kmno4 or impregnated carbons

maybe they have solder wire with smd291 for sale ? if yes then someone could use only smd291 flux + solder wire with 291 and would need only activated carbon filter + prefilter F7 - F9 class thats good idea , there also hakko fa430 fume extractor would be usefull in 100%

[lfldp]

and ive forget

in soldering process we have also alcoholls (small particles) such as isopropylic alcoholl + alcoholls mixed into flux many of them depending on flux type so

the alcohols also is not easy remove by activated carbon for this can be used alumina with kmno4 or impregnated carbon with some oxidisers

the alumina impregnated with kmno4 is usually added to the carbon (mixed) in high-end expensiff filters and not easy to find/buy across europe in small ammount

there is one company who selling it in poland but they have just 6%  which is enough mainly for ethylene removal

you can buy it direct from china for example alibaba ask for 2 - 3kg samples for example there https://www.alibaba.com/showroom/kmno4-activated-alumina.html

violet ceramic balls for formaldehyde removal (whorst to remove) need minimum 8 - 10  % for best even 12%

the % is how many ammount of kmno4 have one ball

i think 2kg of 10% kmno4 alumina would be enough to clean air from all alcoholls + formaldehydes and other smaller particles up to 300m3/h extractor speed , you need to mix it with activated carbon you should give no less than 50% of activated carbon

for example 50% of alumina and 50% activated pelletised carbon or if you wanna use activated coconut carbon you can give 40% of it and alumina 60% , but if you have larger filters you can give much more of activated carbon but no less

if you give less than 50% of carbon (by its weight) then you could fell eye irritation (pinching) caused by kmno4 , activated carbon reduce it when is mixed

so this setup is to remove almost all flux fumes

other cheaper fume extractors use impregnated carbons or catalitic to remove flux fumes (they are very hard to buy) but alumina give best results and have widest spectrum than these carbons

offcourse you can give more alumina for example 5kg the effect would be about yours filters will stand longer (much more longer than commerciall) + you can rise yours extraction speed even to 500m/3h !

[2N3055]

Lead metal is stated to have a vapour pressure of 133 Pa at a temperature of 1000 °C.
Based on a volatilisation enthalpy of ∆Hvap = 177.9 kJ/mol, this vapour pressure can be recalculated with the aid of the Clausius-Clapeyron equation to a vapour pressure of 8.2 * 10-7 Pa at the melting temperature of lead (326°C).

Which means, unless you are soldering in vacuum, there are NO lead vapors when you are soldering. NONE. Science is non negotiable, don't care about opinions and is not defined by urban myths.

Only potential source of dangerous lead in electronics lab/workshop  is desoldering guns and desoldering vacuum pumps that can have quite fine solder dust in it.  Don't eat that, and thoroughly wash hands after cleaning those filters. Dispose of debris and used filters safely.

If you would need any HEPA filter for lead filtration, that would be one on the air exhaust of desoldering station.

Air filtration systems are there solely for purpose of removing flux vapours/smoke and connected chemicals/chemical byproducts.

[lfldp]

Lead metal is stated to have a vapour pressure of 133 Pa at a temperature of 1000 °C.
Based on a volatilisation enthalpy of ∆Hvap = 177.9 kJ/mol, this vapour pressure can be recalculated with the aid of the Clausius-Clapeyron equation to a vapour pressure of 8.2 * 10-7 Pa at the melting temperature of lead (326°C).

Which means, unless you are soldering in vacuum, there are NO lead vapors when you are soldering. NONE. Science is non negotiable, don't care about opinions and is not defined by urban myths.

Only potential source of dangerous lead in electronics lab/workshop  is desoldering guns and desoldering vacuum pumps that can have quite fine solder dust in it.  Don't eat that, and thoroughly wash hands after cleaning those filters. Dispose of debris and used filters safely.

If you would need any HEPA filter for lead filtration, that would be one on the air exhaust of desoldering station.

Air filtration systems are there solely for purpose of removing flux vapours/smoke and connected chemicals/chemical byproducts.

another theory from google said - in 2006 year lead products have been removed from soldering manufactures to avoid workers exposing to lead fumes , tell me whats do you see on bga balls and solder paste stickers  - !!! WARNING !!! MAY CONTAIN LEAD HARMFULL IF SWALLOWED

btw. when you heating pcb on bga rework stations you suposedly generate dioxines and furanes - for cleaning air from these particles you need speciallised carbon or coks , there are some cokses and carbons directed to remove dioxines + furanes + heavy metals and these solder fume extractors for sure cant clean air from these gas particles

[SilverSolder]

One of the articles I read stated that lead could get into the air due to oxides on the surface of the solder - so not really a vapor pressure issue (which I agree is not an issue).

[lfldp]

One of the articles I read stated that lead could get into the air due to oxides on the surface of the solder - so not really a vapor pressure issue (which I agree is not an issue).

right , but we are talking there about small ammount of lead gas from soldering process
and believe me even this small ammount is very hard to clean from air on activated carbon (granulated or coconut)
i did experiments and for example on 6kg of carbon i didnt fell nothing when i heat bga64 balls but when i heat more of lead in short time i starting felling it , so usuall activated carbon could absorb just small ammount of this vapour

[SilverSolder]

One of the articles I read stated that lead could get into the air due to oxides on the surface of the solder - so not really a vapor pressure issue (which I agree is not an issue).

right , but we are talking there about small ammount of lead gas from soldering process  [...]

Yes, the lead gets into the air by help of the oxides on the surface, apparently.  So it isn't actually lead vaporizing (which doesn't happen), it is the oxides on the surface that react with the heat and can end up airborne.   The problem is still the same - bad stuff in the air!

And all the other things, including smoke from rosin solder, are also bad for you.

I am lucky in not being allergic to any of that, but I still have the good sense (like most engineers, I'm sure) to avoid breathing this stuff in, as far as practically possible.

and believe me even this small ammount is very hard to clean from air on activated carbon (granulated or coconut)
i did experiments and for example on 6kg of carbon i didnt fell nothing when i heat bga64 balls but when i heat more of lead in short time i starting felling it , so usuall activated carbon could absorb just small ammount of this vapour

Yes, once we get to the molecular level of cleaning, things begin to get challenging!

[thm_w]

Can we get a citation for lead oxide producing lead gas at <400C temperatures please?

Mention of solder fumes containing Pb, but no mentioned how they were generated: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652541/
This one involves liquids which directly contact the vaporizing coil at ~250C: https://www.jhsph.edu/news/news-releases/2018/study-lead-and-other-toxic-metals-found-in-e-cigarette-vapors.html

[2N3055]

One of the articles I read stated that lead could get into the air due to oxides on the surface of the solder - so not really a vapor pressure issue (which I agree is not an issue).

right , but we are talking there about small ammount of lead gas from soldering process
and believe me even this small ammount is very hard to clean from air on activated carbon (granulated or coconut)
i did experiments and for example on 6kg of carbon i didnt fell nothing when i heat bga64 balls but when i heat more of lead in short time i starting felling it , so usuall activated carbon could absorb just small ammount of this vapour

My answer to that is :

Lead metal is stated to have a vapour pressure of 133 Pa at a temperature of 1000 °C.
Based on a volatilisation enthalpy of ∆Hvap = 177.9 kJ/mol, this vapour pressure can be recalculated with the aid of the Clausius-Clapeyron equation to a vapour pressure of 8.2 * 10-7 Pa at the melting temperature of lead (326°C).

Which means, unless you are soldering in vacuum, there are NO lead vapors when you are soldering. NONE. Science is non negotiable, don't care about opinions and is not defined by urban myths.

Keep reading that over and over.. Until it sinks in....

Only lead that can be harmful is one that is fine dust and can get airborne or ingested by food or fluid intake.
Also, potentially, nanoparticle lead could be absorbed via skin. But that would have to be specially produced material...
That includes lead compounds that it can create with other chemicals..
Many lead compounds and alloys are less toxic than lead alone too.. Some are more ....

So no, don't eat lead, it's not good for  you. But there is no lead evaporation while soldering... No metallic lead fumes.

[SilverSolder]

Can we get a citation for lead oxide producing lead gas at <400C temperatures please?

Mention of solder fumes containing Pb, but no mentioned how they were generated: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652541/
This one involves liquids which directly contact the vaporizing coil at ~250C: https://www.jhsph.edu/news/news-releases/2018/study-lead-and-other-toxic-metals-found-in-e-cigarette-vapors.html

I can't find the article I was looking at, but the lead oxide thing was mentioned in a few places.

I just stumbled over an interesting article that does establish that Pb and Sn fumes exist in the air after melting solder:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652541/#B10

The concentrations of solder fumes were 0.193 mg/ m3, 0.35 mg/m3 and 3 mg/m3 and for formaldehyde, Sn and Pb, respectively. All measurements were obtained in accordance with methods described by the National Institute of Occupational Safety and Health (ASTM, D4185-90, NIOSH 3500 and OSHA 206) using a visible absorption spectrophotometer (Spectronic 20D, Milton Ray, Belgium) and atomic absorption spectrophotometer (ATI/Unicam, 929, USA) (14-16). The soldering wire (alloy 63/67, 0.8 mm diameter, Jarfe Company, Iran) was commercially available.

Looks like we stumbled on the same article! -  At least it seems our testes are safe!

[thm_w]

Good they were using commercial solder.
But they keep referring to welding, "Fumes generated during metal welding have toxic effects on the human body. ". Not sure if that is a translation issue or they specifically mean high temperature welding.


Heres one where they sampled the air and got much less than 3mg/m³ (although the plant may have adequate filtration).

https://pubmed.ncbi.nlm.nih.gov/12701538/

The study group included workers of three plants manufacturing electronic systems, household equipment and electric motors. Membrane filters were used to collect 50 air samples, including personal 8-h samples to assess average weighed concentration of soldering and brazing fumes and their elements, and to assay respirable dust and "background" or "area" samples.

The quantitative analysis revealed that time-weighed average (TWA) of fume concentrations were: soldering fume < 0.5-1.1 mg/m3, Cu < 0.003-0.034 mg/m3, Pb < 0.014-0.037 mg/m3, Sn < 0.15 mg/m3, Sb < 0.035 mg/m3; brazing fume < 0.5-0.8 mg/m3, Cu < 0.003-0.038 mg/m3, Zn < 0.003-0.025 mg/m3, Pb < 0.014-0.023 mg/m3, Ag < 0.014 mg/m3, Sn < 0.15 mg/m3, Mn < 0.07-0.12 mg/m3.

Maybe something was measured here, same sort of low ug range:

Fume concentrations were determined by collection on a membrane filter and analysis by atomic absorption spectrophotometry. Samples were obtained for alloy temperatures of 200 degrees, 400 degrees, and 600 degrees F. In all instances, concentrations were much lower than the applicable occupational limits for continuous exposure.
Lead and cadmium are  the most toxic. Lead and lead oxide enter the body via ingestion, inhalation, and by skin absorption.
Air concentrations were not measured by these investigators, who stressed that the temperatures reached with a  soldering iron, while high, were probably still below the melting temperatures of the component metals (Table 1). However, a cadmium concentration of 16.8 pg/m3 was obtained over a soldering iron (operating temperature unspecified) by others.

Three of 16 air samples for metals resulted in detectable levels of Pb and/or Cd. A personal samples contained 2.06ug/m3 Pb and 1.49ug/m3 Cd. A sample taken over a melting pot showed a Pb level of 46.9ug/m3 and a Cd level of 18.7ug/m3 (visible metal fragments).

https://pubmed.ncbi.nlm.nih.gov/7207418/
https://pubmed.ncbi.nlm.nih.gov/3785004/

[lfldp]

one time in past i did find some informations from weller company measurments cant find them anymore

they claiming about they use hepa filters in they solder fume extractors from 2 reasons

-solder flux fumes microparticles dust
-lead fumes microparticles dust

the hepa filters are recommended by OSHA everywhere where there is lead and kadmium in use

metallic taste in mouth is main proof about lead gas evaporate from leadded solder wire and i dont understand why nobody there did not make simply tests by inhalling both leadded and lead-free solder wires instead of that researching informations from some articles

some of them said yes and some of them said not

the main difference beetwen lead-free/leadded solder wire is about you didnt fell metallic taste from lead-free solder wire so for me this is enough proof of lead gas evaporation from leadded tin , except other symptoms getting while inhalling it but okay someone else maybe wont fell these symptoms or maybe will fellling after 20 years of solder but for sure you will fell this metallic taste in mouth

[SilverSolder]

one time in past i did find some informations from weller company measurments cant find them anymore

they claiming about they use hepa filters in they solder fume extractors from 2 reasons

-solder flux fumes microparticles dust
-lead fumes microparticles dust

the hepa filters are recommended by OSHA everywhere where there is lead and kadmium in use

metallic taste in mouth is main proof about lead gas evaporate from leadded solder wire and i dont understand why nobody there did not make simply tests by inhalling both leadded and lead-free solder wires instead of that researching informations from some articles

some of them said yes and some of them said not

the main difference beetwen lead-free/leadded solder wire is about you didnt fell metallic taste from lead-free solder wire so for me this is enough proof of lead gas evaporation from leadded tin , except other symptoms getting while inhalling it but okay someone else maybe wont fell these symptoms or maybe will fellling after 20 years of solder but for sure you will fell this metallic taste in mouth

Other metals also end up in the air, not just lead?  -  probably best to get rid of all of it...

[lfldp]

one time in past i did find some informations from weller company measurments cant find them anymore

they claiming about they use hepa filters in they solder fume extractors from 2 reasons

-solder flux fumes microparticles dust
-lead fumes microparticles dust

the hepa filters are recommended by OSHA everywhere where there is lead and kadmium in use

metallic taste in mouth is main proof about lead gas evaporate from leadded solder wire and i dont understand why nobody there did not make simply tests by inhalling both leadded and lead-free solder wires instead of that researching informations from some articles

some of them said yes and some of them said not

the main difference beetwen lead-free/leadded solder wire is about you didnt fell metallic taste from lead-free solder wire so for me this is enough proof of lead gas evaporation from leadded tin , except other symptoms getting while inhalling it but okay someone else maybe wont fell these symptoms or maybe will fellling after 20 years of solder but for sure you will fell this metallic taste in mouth

Other metals also end up in the air, not just lead?  -  probably best to get rid of all of it...

hehe
no it is not in short the other metals evaporated from lead free solder arent toxic like lead

everyone who is interessted the molecular sieve type 3A should absorb lead gas - why ? because lead molecular weight is 2,xx , while molecular weight of formaldehyde is 3,xxx < for it fitting sieve 4A but molecular sieves are irritant (even if you mix it with activated carbon) but these much cheaper solution than activated alumina with kmno4

but thats not the end of lead gas story

looks like also activated alumina could adsorb lead gas (its porous structure) so for lead gas we should use activated alumina AL2O3 or AL203 + KMNO4 will works too

the difference beetwen AL203 + KMNO4 than AL203 itself is when this media is impregnated by oxidiser propably loose part of its pore structure and in this form is directed for formaledhyde + alcoholls and similiar vapours removal

but however AL203 standalone is much more cheaper than AL203 + KMNO4 so i need to try it and check

if this media will works ( AL203 or AL203 + KMNO4) my problem with leadded soldering will be solved and i in short i can back to lead soldering because i have enough lead-free soldering from since 4 - 5 years

[SilverSolder]

Yes, you can't beat the qualities of lead in the solder, if you disregard the other aspects!

[2N3055]

Metallic taste in you mouth comes from ions... From flux.....

[SilverSolder]

Metallic taste in you mouth comes from ions... From flux.....

Nothing like a nice apéritif! 

[lfldp]

Metallic taste in you mouth comes from ions... From flux.....

i recommend you to buy 2 solder wires leadded and lead-free (with same flux tbh) from same manufacturer and compare , if you saying about this is flux case because i using many flux and ive never fell metallic taste

[Bud]

This may be related to personal hypersensitivity to particular substances. When i worked in the office i clearly smelled air freshener or detergent smell coming out of the ventilation vents in the room, but noone else did when i asked them.

[thm_w]

Metallic taste in you mouth comes from ions... From flux.....

I mean he would be right, IF you had lead poisoning:

"Very high levels of lead in the blood may cause personality changes, headaches, loss of sensation, weakness, a metallic taste in the mouth, uncoordinated walking, digestive problems, and anemia. "
https://www.merckmanuals.com/home/injuries-and-poisoning/poisoning/lead-poisoning

But that seems unlikely, definitely not something I've experienced. If you do, go to the doctor immediately and get a blood test for lead IMO.