I work in a cancer center. Our radiotherapy department has 12 linear accelerators, and they all use SF6 gas as an electric insulator. Sometimes during routine maintenance the gas needs to be purged and replaced with fresh stock. Recently, there was big debate on how it should be disposed. SF6 is flagged as the most potent greenhouse gas, and the sale of it is starting to become strictly regulated. If the hospital did not provide proof that acceptable procedures were put in place to get rid of it in a green fashion they would deny us gas. Which brought about this question:
If SF6 is 5 times heavier than air, how does it get into the atmosphere? If I filled a bag full of the gas and opened it outside, wouldn’t it stay in a perpetual state of being picked up by the wind and falling to earth? Could it stay in the Stratosphere long enough to trap rising heat and be a serious threat?
The hospital’s solution was to pay a significant amount of money to have it properly disposed. Couldn’t that money have gone to better use?