# Sulfur hexafluoride creation process and risks/safety

I would like to create sulfur hexafluoride and test floating things in it but I am a "chemistry noob" and from what I've read it's non-toxic and generally quite safe but first of all I do not know how to make it (other than that it involves sulfur and fluoride which are both definitely not safe) and the precautions for doing this. Basically: Safe way to make sulfur hexafluoride and how safe is sulfur hexafluoride?

• Better buy it - chemistry noobs should steer clear from gas fluorine. – Mithoron Sep 15 '15 at 18:52
• en.wikipedia.org/wiki/Sulfur_hexafluoride – Mithoron Sep 15 '15 at 18:56
• I'm far from a chemistry noob (and I have experience using CO, HCl and chlorine gases) but I would stay away from any experiment that involves handling fluorine gas and that is in an industrial fumehood. – K_P Sep 15 '15 at 19:34
• On the downside, it is also a very good greenhouse gas, so releasing it into the environment just for fun isn't great. – Jon Custer Sep 15 '15 at 19:54
• That's right: when inhaled, it will do funny things with your voice. It is safe in that it will not react with anything in you, but don't forget that you can't survive without oxygen for too long. – Ivan Neretin Sep 15 '15 at 20:05

The reaction $$\ce{S + 3F2 -> SF6}$$ is strongly exothermic (standard molar enthalpy of formation at $298.15\ \mathrm K$: $\Delta_\mathrm fH^\circ=-1220.5\ \mathrm{kJ/mol}$[1]). In the fluorine stream, sulfur burns with a blue flame.
Sulfur hexafluoride is collected in the cold trap. The product contains various impurities, such as $\ce{F2}$, $\ce{HF}$, $\ce{SOF2}$, $\ce{SO2F2}$, $\ce{SF2}$, $\ce{S2F2}$, $\ce{SF4}$, and $\ce{S2F10}$. Most of the impurities are easily hydrolysable; therefore the gas is passed through a washing bottle filled with $\ce{KOH}$ solution. However, $\ce{S2F10}$ has to be removed with activated charcoal or decomposed by pyrolysis at $400\ \mathrm{^\circ C}$ according to $$\ce{S2F10 -> SF4 + SF6}$$