I think everything that everyone has said thus far in this thread is very wise indeed.
I used to have to compound similar materials from scratch.
The JET dust extractor from the likes of MSC have about 32 micron filtration.
Patent US2111734 - Syntactic Foam Compositions, Pipelines Insulated with Same, and Method - Google Patents
^^^ If you glance at the claims on this patent for certain types of Expoxy, "micro balloon" filled materials the particle size can range from 1 micron to 100 micron depending on that application. In this application they seem have banded applications from 50nm to 10 micron, and 10 micron to 20 micron.
The problem is sometimes the harmful components are simply not visible and it may be that the JET filtration at32 micron could indeed let harmful particulates pass through.
At NASA (for "Human spaceflight/space craft engineering") because of (effective) zero G, everything floats about so everything has to be very clean as possible. But some of these fine particulates do a great job of "Floating about" for a really long time on Earth, especially in enclosed environments.
Moon Machines - Part 4: The Lunar Module - YouTube
^^^First few minutes of insertion point.
Moon Machines - Part 4: The Lunar Module - YouTube
^^^First few minutes of insertion point.
Criteria for cleanliness...
"If there are particles of certain size per cubic inch, then the Astronaut may have an itchy eye..."
"If there are so many particles (per cubic inch) and they are bigger he will get a sore throat".
"If they are bigger still, ... he could bleed",
"If they are bigger still he is in danger of his life".
The other weird thing about Epoxies is that they have the capability to make someone VERY depressed, (but that's usually for folks mixing accelerator/two part compounding), but historically those that have worked with plexiglass, (cutting) and Phenolic resin over a long periods of time have exhibited serious neurological problems which are permanent. Not sure if small particulate epoxy would do the same thing?
I know for a lot of hazardous materials and particulates an Airflow helmet (fed by positive pressure) can be much less hassle than appropriate level of filtration mask and glasses. The air flow helmets are more pricey, but if you do a lot of this stuff then that would be much more comfortable for long periods of time (depends how much you have to move about). I never managed to get on with high filtration face masks as it's really difficult to breathe through them. ... And hence not take adequate precautions.
It sounds like anything you do will be an improvement but definitely don't take you health for granted.
