The colourful, rubberized clogs or shoes are extremely popular among nurses in North America in general.

But hospital administrations across Canada have begun to ban them inside hospital premises saying they are a health and safety hazard.

Nurses and doctors love Crocs because they are light, easy to clean and, most of all, comfortable.

But there are concerns with ventilation holes on the front and the open heel. When working around blood, bodily fluids and sharp objects like syringes, the holes can prove to be a hazard.

"According to us, the Crocs shoes are not safe at all," one expert said.

"Because they are not strong shoes, they are not protective if heavy objects fall - and if needles fall, nurses can get hurt."

The footwear is currently prohibited at Vancouver Coastal Health, the Ottawa Hospital and the Hospital for Sick Children, and the Hamilton Health Services.

The Ontario Hospital Association has sent a bulletin to about 100 hospitals citing safety concerns for health-care employees wearing Crocs.

The Winnipeg Regional Health Authority in Manitoba is also reviewing whether Crocs pose a safety threat.

Hospitals are also concerned with reaction times being compromised, because clogs are more difficult to run in than traditional hospital footwear.

Another charge against Crocs is that they act as insulators, enabling enough static electricity to be built up to knock out medical equipment.

A few months ago, a Swedish hospital banned its staff from wearing Crocs because they were blamed for at least three incidents in which respirators and other machines malfunctioned.