halp

[Beugle]

am i able to build a biofuel refinery inside my base as long as it has like ventilation and not around anything that can catch fire?

[Max Planck]

You should definitely build it under a roof as it doesn't like rain at all. I learned that the hard way.

[HunterSilver]

Yes. No workstation puts out any kind of fumes or gases that are harmful to your colonists. It is in fact bad to build workstations outside or in unroofed areas. So build your biofuel refinery inside of your base.