Playgrounds and Helmets Don't Mix!
Summary: Children should not wear helmets on playgrounds or when climbing trees. The helmet can snag and the strap can asphyxiate them. Several deaths have been recorded, and more close calls. In Australia, three children have died at home in similar incidents.
On February 4, 1999 a Pennsylvania child was asphyxiated while wearing a bicycle helmet and playing on playground equipment. Evidently he was caught between two overlapping horizontal platforms when his helmet would not fit through the gap between them where his body had already gone. Pressure on his chest as his lower body dangled prevented him from breathing. The gap was measured by reporter Mark Scolforo of the York Dispatch at 8.75 inches. That would not be permitted under the ASTM playground equipment standard. It bans all openings from 3.5 to 9 inches.
The 1999 Death
While there are still details about the helmet and equipment to be investigated, it is now evident that it can happen here. A few earlier incidents in Scandinavia and Canada had been reported, but none had surfaced in the US. We had attributed that to the US playground equipment standard. But we now know that several incidents have been reported where injury did not result.
Unlike the Pennsylvania incident, the Canadian and Scandinavian incidents were "hangings" where the child was strangled by the helmet strap. A strong strap is necessary to keep a helmet on the child's head during a crash, and helmets with strong straps have saved hundreds or thousands of lives, so these incidents must be seen in that perspective.
The potential for strangulation by a helmet strap on playground equipment has been known since several such incidents were reported in Scandinavia. We received a report in 1992 from Anders Slatis, then a consultant for a Swedish helmet manufacturer, documenting six cases from 1984 to 1992
of asphyxiation by helmet straps when the helmets caught in Swedish or Norwegian playground equipment. All victims were boys under six. "Thirty or forty" more incidents occurred without injury. A new European playground equipment standard bans openings between 110 and 230 mm (4.3 to 9.1 inches). Slatis said that for this reason the Swedish child helmet standard will require a strap to hold at 90 N (9 kg) but release before 160 N (16kg), which Slatis believes might have saved two of the six lives lost. The European EN 1080 standard for child helmets now has such a buckle, colored green to distinguish it from other buckles, but it is optional. In the period after it was added to the standard there were reports that it was problematic, and that parents were avoiding it. At present, there are green buckles on child helmets sold in major toy stores and department retailers, but regular buckles on child helmets sold in some other stores where the retailer believes in stronger straps.
In the US, the ASTM F-1487-95 standard for playground equipment adopted in 1995 banned all openings from 3.5 inches to 9.0 inches. Thus it was already in line with the dimensions adopted in Europe in response to this problem. The space where the child was caught has been measured by the Scolforo as 8.75 inches.
Troxel, formerly a major US bicycle helmet manufacturer, reported in 1997 that one of their helmets had been involved in an incident where it snagged on a swing and a child was nearly choked. At that time Troxel added a general warning to their helmet labels to the effect that use in activities other than bicycling could result in a choking hazard. We have also heard from one parent in the US whose child was saved by the intervention of a neighbor when the child's helmet caught in a tree.
Standards organizations in this country considered the Scandinavian evidence but did not take action because no similar incidents had been reported in the US. The assumption was that US standards for playground equipment were ensuring that our equipment that did not have the hazard.
In 2006 another incident was reported in Salt Lake City. The victim was a four-year-old boy who died when he fell from a playset with multiple stations attached to a horizontal ladder. In that case the helmet was not a factor, since the child did not die of strangulation by the helmet strap, but from the force of the initial fall.
Playground Equipment Standards
In February, 1999, we contacted Dr. Donna Thompson of the National Program for Playground Safety, who is also Secretary of ASTM F-15.29 on Playground Equipment. (Their standard is F-1487) Dr. Thompson says the openings in playground equipment have been sized for bodies, not bodies-with-helmets. (But see notes above on Swedish and US standards.) They were aware of the potential for a helmet to hang but had not addressed it since there were no reports of problems here. They had had difficulty adding a signage requirement on appropriate ages for use of the equipment to their standard, but if they do add signage it might also include a "take off your kid's helmet" warning. After they heard about an incident in Canada in 1998, the committee suggested that CPSC issue a warning.
The Consumer Product Safety Commission issued a warning on this subject in 1999. They had not thought it necessary before this incident. They have been concerned about scaring parents away from putting helmets on their kids, since the more critical danger is the ride to the playground, not the rare strangulation or asphyxiation when there.
CPSC Issues Warning
Here is the wording of the CPSC warning:
Consumer Product Safety Alert
From the U.S. Consumer Product Safety Commission, Washington, D.C. 20207
Wear Bike Helmets On Bicycles -- Not on Playgrounds
The U.S. Consumer Product Safety Commission (CPSC) warns that children should not wear bike helmets when playing, especially on playground equipment. CPSC has reports of two strangulation deaths to children when their bike helmets became stuck in openings on playground equipment, resulting in hanging. CPSC also has reports of four cases where no injury occurred. In two of these cases the children were climbing trees, and in the other two cases the children were on playground equipment.
Children should always wear helmets while riding their bikes. But when a child gets off the bike, take off the helmet. There is a "hidden hazard" of strangulation if a child wears a helmet while playing on playground equipment.
Although obviously all parties concerned do not want to overreact to a rare accident, it became evident by 1999 that action was required before more deaths resulted. The ASTM F8.53 Headgear standards subcommittee discussed this item in its Seattle meeting on May 20, 1999. An option for the short term was adding a requirement for a warning label to the ASTM F1898 Infant-Toddler Helmet standard, and perhaps its adult bicycle helmet standard as well. It may also be possible to improve the shape of youth helmets to avoid snagging. But the Subcommittee members felt that weakening the current buckles to prevent a very small number of strangulation incidents would put a huge number of infant and child riders in jeopardy of losing their helmet in a crash and hitting the pavement unprotected. The tradeoff is clearly not worthwhile, since many more deaths and injuries could result from the weaker buckle.
As noted above, the EC developed a European standard for a weaker child's buckle with a green color code. Experience with that buckle should permit more progress.
When these incidents first came to our attention the Bicycle Helmet Safety Institute put this information up on a number of its web pages, sent out an alert to members of the ASTM F8.53 Subcommittee, sent out an email Alert and sent a postcard to all who received our Update by mail. For the longer term we have suggested to manufacturers who participate in ASTM standards development that we need a "slow release buckle" that would pass the current ASTM standard for severe jerks but would also release after 3 to 5 seconds of sustained pull. The technology for such a buckle does not currently exist, and developing it will pose some formidable obstacles. But the payoff in children saved would be worth the effort and expense even if the number of lives saved would be very small. It is not clear, for example, that such a buckle would have saved the child in Pennsylvania.
More recently we have been told that at least one Swedish manufacturer has researched the problem and believes there are many children saved from serious injury on playgrounds or elsewhere because they had their bike helmets on. It is not easy to balance the potential loss of a life vs. the potential for serious head injury in others.
Back in 2006 the Scandinavian helmet manufacturer Etto said they were developing a unique new buckle-release system that opens the buckle hydraulically if the child is hung up for more than a few seconds. Etto intended to market this buckle eventually, but they do not produce helmets for the US market, and we don't know if they intend to license the technology or not. We purchased samples in early 2006 of a helmet that was said on their web page to have the new buckle, but they arrived with conventional buckles and the manufacturer said the new buckle had been delayed in development. We have not seen it advertised since. If you see such a helmet advertised by Etto we would recommend confirming that it has the new slow release buckle before ordering it. If the technology is hydraulic, it will be very different from any buckle ever used on a bicycle helmet to date. As of 2014 we have still not seen the hydraulic buckle.
Parents should make sure their children remove their helmets before climbing trees or playing on playground equipment. They should also remove hood and neck drawstrings from children's clothing and outerwear and don't let kids wear necklaces, purses or scarves on the playground. Parents should also check their playground equipment against the ASTM standard to determine if there are hazardous configurations, particularly on older equipment or anything locally made. And the injury prevention community seems unanimous in recommending parental supervision of very young children whenever they are using a playground.
What should a parent be doing?
Update in April, 2011
The Medical Journal of Australia has published a report from four doctors there who examined medical records for reports of children strangled by bicycle helmet straps.
They identified three cases of deaths from hanging between 2001 and 2010:
The authors conclude that:
- a 2-year-old boy who was suspended by his helmet strap between a bunk bed and a wall
- a 3-year-old boy who was suspended by his helmet strap when he tried to climb out of a home window
- a 5-year-old boy who was suspended from an overhead clothesline while jumping on a trampoline
These cases show that accidental hanging is still occurring among young children who wear bicycle helmets while engaging in activities other than bicycle riding.
Bicycle helmets and accidental asphyxia in childhood
Roger W Byard, Allan Cala, Donald Ritchey and Noel Woodford
Medical Journal of Australia 2011; 194 (1): 49