The problem is just about any foreign particulates at a high enough concentration will cause adverse effects when inhaled [1].
If the machine had a large residue of metal dust from manufacturing, or a grinding in the motor which made it into the airstream, there are severe consequences [2].
A similar issue could if there was some sort of wood dust [3] that made it into the airstream (e.g if they had a wood trim for aesthetics, and it was shaved down by the motor and made it into the air stream). If instead just the dampening of the wood caused mold spores to grow that made it into the air stream [4], that could also cause major issues.
So yes, in this case it's foam, but most foreign particulates are going to be a problem.
If the machine had a large residue of metal dust from manufacturing, or a grinding in the motor which made it into the airstream, there are severe consequences [2].
A similar issue could if there was some sort of wood dust [3] that made it into the airstream (e.g if they had a wood trim for aesthetics, and it was shaved down by the motor and made it into the air stream). If instead just the dampening of the wood caused mold spores to grow that made it into the air stream [4], that could also cause major issues.
So yes, in this case it's foam, but most foreign particulates are going to be a problem.
[1]: https://www.ccohs.ca/oshanswers/chemicals/lungs_dust.html#se...
[2]: https://lunginstitute.com/can-breathing-metal-dust-hurt-you/
[3]: https://www.osha.gov/wood-dust
[4]: https://www.mayoclinic.org/diseases-conditions/aspergillosis...