Working on ice gets new guidelines
January 26, 2010 by J. Swiss
Working on ice is a cold reality for many oilfield workers and while much has been published about the hazards of frostbite and hypothermia, there is a major risk below the ice’s surface that until recently, has been largely misunderstood.
A fall through the ice into the freezing water below presents a “risk that can have potentially life-threatening consequences” for truckers, oil well drillers, survey and scientific crews and anyone else who must work outside during the winter. But surprisingly, a person dressed in winter clothing can survive emersion in cold water for as long as one hour, and as long as two hours if they can get above the surface of the water.
When someone falls through the ice, they have:
- One minute to control breathing. For about one minute, the person gasps for air in reaction to contact with the cold water. After one minute, the gasping subsides, the skin numbs and the sensation of intense cold decreases.
- Ten minutes of meaningful movement. The person has about 10 minutes to get out of the water before they are unable to help themselves.
- One hour before losing consciousness. If the person manages to hang on to the ice or stay afloat after 10 minutes, the muscles in their arms and legs lose the strength to get them out of the water. Eventually they lose consciousness as their core body temperature decreases to about 30°C.
- Two hours to be found. If the person stays above the surface of the water, rescue is still possible within two hours. After that time, death due to hypothermic cardiac arrest occurs when the body’s core temperature falls below 28°C.
(Giesbrecht, G. and A. W. Walker, 2006)
To improve the protection of workers on ice, an Alberta-based multi-stakeholder advisory committee with experience in designing, building, maintaining and operating on ice covers was formed to create workplace guidelines and supporting materials for ice covers. In October 2009, the committee released a document titled Best Practice for Building and Working Safely on Ice Covers in Alberta.
When the LibraSystem™ is updated in late January, a new safe work practice dealing with working on ice will be added.
Sources:
- Bill Corbett, Alberta Occupational Health and Safety Magazine, January 2010.
- Giesbrecht, G. and A. W. Walker, Hypothermia, Frostbite and other Cold Injuries: Prevention, Survival, Rescue and Treatment, 2nd edition. The Mountaineers Books, 2006.