A global helium shortage continues to squeeze stock to notably low levels, deflating business for some party planners and forcing some scientists to stretch modest supplies.

Supplies of helium — which is extracted from natural gas — were first reported to have sunk to record low levels in 2006 as refineries in the U.S., Algeria and Russia reported production problems.

The growing use of MRI machines, which use helium to super-cool magnets, in hospitals around the world is also contributing to the demand.

Retailers have steadily absorbed the rising costs of the gas but now some businesses are reporting access has been cut entirely.

"We were told there's no helium, so that's going to change the face of our business, temporarily if not long term," said Leah Garven, who runs a party decorating business in Saskatoon.

"We've been trying to figure out what we can do with air and still satisfy the customer because let's face it, everyone loves a helium balloon."

Meanwhile, scientists at the Canadian Light Source Synchrotron at the University of Saskatchewan in Saskatoon say they're also facing delays. Emil Hallin, CLS experimental facilities manager, said the Synchrotron — a particle accelerator — is dependent on the gas.

"Being able to operate our electromagnets at super-conducting temperatures is really important for their high performance, as is the ability to operate our accelerators at liquid helium temperatures," Hallin said.

He expects it will be several months before refineries build up stock helium levels.