Suction entrapment
From Wikipedia, the free encyclopedia
Suction entrapment is the actual cause of death in many drownings in swimming pools, spas, and jetted bathtubs. This occurs most often when drain covers are too small to safely handle the flow of water, resulting in hair entrapment, and less often when the cover is broken, missing, or has been removed by people who don’t know the exposed suction fitting can result in body, limb, or evisceration hazards. When a swimmer playing on or near the open suction fitting becomes stuck it is much the way the hose of a vacuum cleaner sticks to your palm. The force of a pool’s suction can be tremendous: 740 pounds of force (3.3 kN) for an 8-inch round main drain with a standard pump operating at sea level (50 sq in x 14.7 psi). This “suction entrapment” will hold the bather in its grip until the vacuum is broken. In cases where the bather stuck their hand or foot in the suction pipe, they could not be freed even after the pump was turned off.
[edit] Prevention is the key to suction entrapment avoidance
Entrapment is completely avoidable if a pool and/spa is built without a submerged suction outlet (drain). Many pools/spas are built with drains. Few people know this hazard exists and there are high profile cases where bathers were trapped while being supervised because the hazard is not obvious, especially in the case of Hair Entrapment, when the drain cover is in place and properly secured. Property owners must be aware of the potential hazards, taking responsibility to assure their pool, spa or jetted tub is safe by treating pump suction with the same respect as electricity; neither can be seen by potential victims.
The US Consumer Product Safety Commission publishes information on the subject and more and more government regulators are addressing the issue through new building standards. Other sources of information are readily available by searching the internet.
Within the United States, the Consumer Product Safety Commission, Child Safety Advocates, Standard Writing Associations, and Trade Associations are working together to identify and solve the problem once and for all. A scientific classification of Suction Entrapment Hazards was first produced by the Association of Pool and Spa Professionals (APSP) Technical Council identifying five unique suction entrapment hazards based a thorough review of all available U.S. Consumer Product Safety Commission, Epidemiologic Investigation Reports. The five hazards account for all reported incidents, but not all are technically caused by “suction,” for example there is only one documented case of Mechanical Entrapment, and that is a necklace stuck in a bathtub drain. Additionally Limb Entrapment is not dependant on suction, any opening large enough for a hand or foot exposes the swimmer to a limb entrapment hazards that is similar to having a ring stuck on a finger.
[edit] Five suction entrapment hazards
- Hair entrapment or entanglement (hair is pulled in and wrapped around the grate of the drain cover, or turbulence behind the cover causes the hair to puff up, or “rats nest” making it too matted to pull back through the opening).
- Body entrapment (a section of the torso becomes entrapped).
- Limb entrapment (a hand/arm, or foot/leg pulled, or inserted into an open pipe).
- Evisceration (the victim’s buttocks come into contact with the pool suction outlet and he or she is disemboweled).
- Mechanical (jewelry or part of the bather’s clothing gets caught in the drain or the grate)
The Consumer Product Safety Commission, the federal agency charged with gathering suction entrapment data, says its numbers are not completely reliable. This is due to a lack of awareness on the part of emergency personnel, who often report entrapment casualties simply as drowning victims. In the wake of tragedy, the physician will likely name the cause of death as “drowning.” The CPSC announced an initiative to improve suction entrapment reporting during a national hearing on Pool and Spa Safety held July 24, 2004 in Phoenix, Arizona.
