PCB router dust extractor Hepa filter class

Thread Starter

PZUFIC

Joined Jan 7, 2012
44
Hello,

I don't have any experience and knowledge about hepa filters, so that's why I'm asking here in a hope that there is someone with enough knowledge.
Is H12 (EU standard) rated filter as final filter enough for the vac used for PCB router dust extraction?

Thank you very much in advance and have a nice day.
 

jpanhalt

Joined Jan 18, 2008
7,874
You have not provided enough information to recommend a specific filter. Why do you want a HEPA filter on the exhaust? What size particles do you want to trap?

Concerns about dust are real. Some dust is quite dangerous (e.g., beryllium, asbestos, crystalline silica). Other dust is "nuisance" (PNOC: particulates not otherwise classified). Do you consider PCB dust dangerous or a nuisance dust? What maximum level do you want to remain under?
 

Thread Starter

PZUFIC

Joined Jan 7, 2012
44
As I already mentioned I'm asking because I don't know. I'm in a search for a vac and the one that I found suitable is available with H12 hepa filter. The company that makes the routers also sells dust extractors for them, but if you ask me they are greatly overpriced for what they are. They also include hepa filters but the class is not stated.

I need to know if the H12 filter would be enough to use for dust extraction on a PCB router to not pose any noticeable health damage to the people present in the room. It will be used for a couple hours a month.
 

Thread Starter

PZUFIC

Joined Jan 7, 2012
44
You have not provided enough information to recommend a specific filter. Why do you want a HEPA filter on the exhaust? What size particles do you want to trap?

Concerns about dust are real. Some dust is quite dangerous (e.g., beryllium, asbestos, crystalline silica). Other dust is "nuisance" (PNOC: particulates not otherwise classified). Do you consider PCB dust dangerous or a nuisance dust? What maximum level do you want to remain under?
I hope I provided enough information above. As far as I can see you are experienced in this topic, so I would be pleased if you can make an opinion.
 

jpanhalt

Joined Jan 18, 2008
7,874
The regulations specify PEL's for the environment. As far as I could find, they do not specify which specific filter class should be used to meet those PEL's. That's not unexpected as the performance of your system will depend on numerous variables of which the filter class is just one. If you are covered under OSHA (USA) or its equivalent in your country, you would be required to show that particulate levels during and after routing are within limits. There is a whole industry devoted to such assessment. 3M is prominent in that industry and makes several devices approved for that monitoring.

Here are two relevant government publications for the US. The first is perhaps most on point:
https://www.osha.gov/dts/osta/otm/otm_ii/otm_ii_1.html
https://www.osha.gov/dts/osta/otm/otm_viii/otm_viii_2.html

If you change the scene from filtering the exhaust to filtering the individuals (e.g., facemasks), there are 12 categories. Looking only at the category for non-oil containing particulates, the categories are N95, N99, and N100, which filter 95%, 99%, and 99.97%, respectively, of particulates greater than 0.3 micron. From an overall perspective, I get the impression that N95 is for most nuisance dusts. That would correspond roughly to an H11 class (i.e., 95% of 0.1 micron). Moreover, I suspect particulate size created by routing with a cutter (vs. grinding) will be quite large.

Based on those assumptions and the comparison to facemasks, I think an H11 or H12 should suffice. Of course, airflow will make a huge difference, and you may be able to get greater extraction efficiency more economically with the H11 as compared to the H12. The final assessment, however, will be measuring the particulate concentration in the environment (i.e., does it meet PEL's requirements).
 
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