I’m also going to assume that Renshape has the same problem as wood.
Renshape is safer than wood - it’s essentially sterile and non-toxic… however it still generates particles in the dangerous range.
What about wax?
Wax is fine, as are plastics as long as one doesn’t machine them until they smoke and/or burn.
Friable (easily crumbled) materials (e.g. wood, Renshape, FR4, Garolite, Fiberglass) generate particles when CNCed that are extremely dangerous to ones health. Medium Density Fiberboard (MDF) is some of the nastiest stuff around.
The visible particles can also be dangerous. MDF (often used for spoiler/waste boards) and hardwoods - especially exotic (tropical) hardwoods - contain toxic substances and even viruses that can be nasty.
One needs to have a dust collector (vacuum element) with a HEPA filter rated at 0.3 microns to meet or exceed the known safety requirements. HEPA filters tend to be expensive - US$80-100 is not uncommon - so we add a dust separator - a cyclone - to separate out 98+% of the particles before they get to the dust collector.
The good news is that good dust collectors and separators are not expensive. Add some appropriate tubing and you’re all set.
Setting things up such that there is sufficient air volume and velocity to pick up the particles takes a bit of care but is not difficult to understand or achieve. One common accessory is a dust head - a mount for a vacuum hose and brush/skirt that goes on (or near) the spindle. This greatly improves the dust collection efficiency makes cleaning up a snap - often none at all.
A dust head is a relatively easy project - you’ve got a CNC machine so you can make one! @Flatballer has posted one design and @patofoto is working on another.
If you’re looking to properly dealing with wood, let me know and we can discuss it.
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