CPSC Definition: Hair Entrapment/Entanglement
CPSC is aware of 43 incidents of hair entrapment or entanglement in pools, spas, and hot tubs between January 1990 and August 2004. Twelve of the incidents resulted in drowning deaths, as a result of hair becoming entangled in the drain grates. Thirty-eight incidents occurred in spas, including hot tubs, and five occurred in a pool. The victims’ ages were between 4 and 42, with a median age of 9 years – 92.5% were under the age of 15 (Ref. 1).
Typically, these incidents involve females with long, fine hair, who are underwater with their head near a suction outlet (drain). The water flow into the drain sweeps the hair into and around the drain cover, and the hair becomes entangled in and around holes and protrusions on both sides of the cover. Entrapment occurs because of the tangling and not necessarily because of strong suction forces, although the suction forces initially draw the hair into the drain cover.
Since about 1982, industry voluntary standards for pools, spas, and hot tubs require drain 5 covers to be certified. The certification includes a maximum flow rate, in gallons per minute (GPM), which should never be exceeded, as this increases the possibility for hair entrapment/entanglement. The design of a drain cover in association with the flow rate through it has been found to relate to the cover’s ability to entrap hair. Large openings in the covers in combination with high flow rates can pull hair through the cover and cause entanglement in the turbulence behind the cover. Reduced flow rates and smaller holes in the drain cover can make entanglement less likely to occur. However, it can be difficult to determine actual flow rates in pools and custom-built spas, and thus to know if they are equipped with the proper fitting to prevent hair entanglement. Drain covers available on the market since 1982 are supposed to conform to a standard that provides hair entrapment/entanglement protection.