How do I know if a filament is abrasive?
A filament made of pure plastic won't be abrasive. The abrasion comes from the added particles.
Filaments with added particles of any kind (there are not so many after all: glass/carbon fibres, metals, glow in the dark, wood, stone) will usually be always be advertised as such because they always carry a higher price tag compared to the plain plastic, therefore you know that it contains potentially abrasive particles.
Once you know that particles are added, most of the time they will be abrasive: as far as I know, only cork is not, any other kind of particles I listed (including wood particles) may easily scratch brass.
If it were your printer, we could discuss how much each kind of particles will abrade, but in your case the ban seems to be complete, therefore only plain plastics (including &quot;plus/+/Pro&quot; blends, like for PLA and ABS) are allowed.