PCB's dust is toxic or not (fiberglass)

jpanhalt

Joined Jan 18, 2008
9,339
There are several lists of PEL for substances. Here is just one list: https://www.osha.gov/dsg/annotated-pels/tablez-1.html
You might also want to search more specifically on "nuisance dust."

It is no surprise that there are limits for an awfully large number of things. Does one really expect a regulator agency to say , "no danger?" In reality, nuisance dusts shouldn't cause undue alarm. A PEL of 15 mg/m^3 is quite common.

Of course, you shouldn't breath it, nor should you stick your head in a full vacuum cleaner bag and inhale deeply. Just avoid and use common sense. Fiberglass dust and dust from carbon fiber laminates have been extensively studied. They are not asbestos nor nearly as dangerous..
 

BobaMosfet

Joined Jul 1, 2009
1,104
It's not toxic using the usual definition, but you shouldn't be breathing it. It could cause respiratory problems.
PCB resin (aka FR4 - which is the most common) is fiberglass. It's dust most certainly _IS_ toxic, and should not be inhaled (in the event someone is cutting or drilling the PCB).
 

dl324

Joined Mar 30, 2015
10,703
PCB resin (aka FR4 - which is the most common) is fiberglass. It's dust most certainly _IS_ toxic, and should not be inhaled (in the event someone is cutting or drilling the PCB).
That isn't how I'd define toxic:
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Death? Serious debilitation? Don't think so.
 

spinnaker

Joined Oct 29, 2009
7,835
This is what I don't get about milling PCBs. Many people tout this as a chemical free process. Big whoop. Look at all of the dust you are making in milling. That is far more toxic than chemicals. I use hydrochloric acid and peroxide. You need use it in a well ventilated area and it is reasonable safe. I open my garage door. I am considering buying a mask but I etch so rarely good ventilation is probably good enough.

If you want to be even safer than use ferric chloride.

If you mill you are really going to want a dust extractor and wear a dust mask. But you still have a problem with residual dust in the workspace.
 

jpanhalt

Joined Jan 18, 2008
9,339
I only use FR2 boards on my mill. Apart from the lower risk from dust, the tools last a lot longer too.
Are you sure that FR2 is less "toxic" than FR4? FR2 is a phenol formaldehyde resin -- the sort of resin that has been a subject for debate on its use in homes because of its toxicity when burned.
 

AlbertHall

Joined Jun 4, 2014
9,821
Are you sure that FR2 is less "toxic" than FR4? FR2 is a phenol formaldehyde resin -- the sort of resin that has been a subject for debate on its use in homes because of its toxicity when burned.
But I'm not burning it.
I believe FR4 releases cyanide when burnt.
 

jpanhalt

Joined Jan 18, 2008
9,339
FR2 shows decomposition well below the temperature at which it burns.

Simply, you state that dust from FR2 is less dangerous than dust from FR4. Of course, you are entitled to that opinion, but that doesn't validate it. Both are classified as nuisance dusts effectively. That is, the PEL is 15 mg/m^3. FR2 appears to fall under PNOR (see below).

Here are some other dusts with PEL's of 15 mg/m^3 (See: table link in post #4): particulates not otherwise regulated (PNOR), cellulose, emery, glycerin, graphite, gypsum, sucrose, and starch. Surprising to me, grain dust (oat, wheat, and barley) has a PEL of 10 mg/m^3. Iron oxide (rust) is also 10 mg/m^3.
 

Uilnaydar

Joined Jan 30, 2008
118
Cutting the fiberglass truck liner off of a vehicle to get to the victim after a crash, screwed me up for months.... don't do it. (Yeah yeah I wasn't masked up.... sue me)
 
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