Is it safe to run a laser indoors or in an apartment?

Yes, with three non-negotiables: an enclosed machine (or full enclosure), active smoke extraction — ducted out a window or through a real HEPA+carbon fume extractor — and a fire plan (extinguisher in reach, never leave the machine running unattended).

Apartment makers usually land on an enclosed diode plus a desktop extractor, sticking to wood, leather, and anodized blanks while avoiding heavy MDF and big acrylic cut jobs that overwhelm small filters. Your nose is the audit: if the room smells like the job, the extraction is losing.