Green Fire Safety Information
Boric acid is a relatively safe household chemical. This is an outdoor project. There isn't a lot of smoke produced, nor is it particularly toxic, but the heat is intense. It will set off your smoke alarm.
The borax i used for this experiment is from the brand 20 mule team witch has 99.5% purity (there is about a half of 1% of naturally occurring trace minerals) so I recommend using it for this experiment.
The only hazardous part of the experiment is making the boric acid (because of the use of HCl), but you can avoid this part by buying it, or you can use copper sulfate as an alternative (sold as a root killer).
The only gas produced in this reaction is CO2 and some water vapor, because of the combustion of methanol; Borax and boric acid don't burn up or produce gases, simply the electrons of boron get exited because of the energy produced from the combustion of methanol and the boron electrons re-emit this energy as a green flame.