Archive for January, 2012

Are the Current Thresholds Adequate in the ASTM F1292 Specification for Impact Attenuation of Surfacing Materials Within the Use Zone of Playground Equipment?

Tuesday, January 24th, 2012

by Kenneth S. Kutska, CPSI
Executive Director, International Playground Safety Institute, LLC
January 28, 2009

Since the very beginning of tracking and analyzing playground injuries to children it has been know that “Falls to the Surface” has been the number one most common cause of serious injuries to children. Knowing who falls to the surface, how they fall, where they fall from, what part of the body first impacts the surface have a profound impact on the type and severity of impact injuries to children. This information coupled with a myriad of variables related to the surface material one falls upon makes for a never ending discussion on whether performance requirements are adequate in today’s litigious society. The playground industry performance standard commonly used is the ASTM F1292 Standard. The scope of this standard is to reduce serious head injuries. Any surface system installed within the use zone of a public playground must have a maintained critical height which exceeds the fall height of the equipment. The critical height of a surfacing system is the height in full feet below which a life-threatening head injury would not be expected to occur on the surfacing system. The critical height of a surface system is the fall height when tested in accordance with ASTM F1292 which results in a peak deceleration to the head during impact of 200 g’s or less and/or peak deceleration of the head during impact related to the duration of deceleration of 1000 HIC or less.

In recent years there has been a large increase in the use of unitary surface systems as a means of complying with the ADA/ABA Accessibility Guidelines. Regardless of all the improvements to impact attenuating surface systems since 1991 there has been an increase in fall related injuries primarily in arm and leg injuries. Why is this? Is it a lack of maintenance? Is it a lack of sufficient depth of loose-fill materials? Is it environmental factors or loss of impact attenuation properties as a result of an aging surface material coupled with some of these environmental factors?

It is probably a combination of all of these factors. The major increase in injury data seems to be directly related to the type of surface system. More arm and leg fractures are occurring on unitary surface systems versus loose-fill surface systems. Is this because of ADA/ABA accessibility requirements? Do loose-fill surface systems allow for displacement of surface materials or is it the ability of the surface to disperse this energy at initial impact?

Advocates for injury prevention on children’s playgrounds have been questioning the effectiveness of the current industry safety standards and challenging the scope of the ASTM F1292 standard and the compliance thresholds established to reduce serious head injuries to children.

I recently participated in a in-depth educational session that focused on understanding the various factors that determine a public playground owner/operator’s compliance to the industry’s minimum performance standards related to ADA accessible public playground impact attenuating surfacing systems within the use zones of playground equipment. It is imperative owner/operators understand their responsibility to purchase, install, maintain, inspect, and document compliance of their playground surfacing systems throughout the life of the playground.

Challenges to this compliance will be made in the event of a serious injury to a user even if the injury is not a life-threatening head injury. If the surface system is found to not be compliant to all the standards it will be argued the injury may not have occurred. While the scope of the F1487 standard is the reduction of life threatening and permanently debilitating injuries; many have been arguing long bone and growth plate fractures are permanently debilitating even though the ASTM F15.29 Subcommittee has repeated stated that long bone fractures of any type were not within the current scope of the standards.

Arguably, advocates for injury prevention would like to see a decrease in public playground injuries requiring emergency room treatment. The reality of this goal would be to lower heights of equipment, reduce motion in equipment, and all but eliminate the element of risk and challenge within children’s environment. The elimination of challenge and risk in play environments is known by child development experts to significantly reduce the value of the play experience and the developmental benefits of play.

Before we go any further with the analysis of playground safety surfacing systems there should be a thorough search, documentation, and review of research studies completed prior to and after 1990. The last thorough search and analysis I am aware of was conducted for the United States Consumer Product Safety Commission by the COMSIS Corporation of Silver Springs, Maryland. This was completed in March of 1990. The conclusion of this study as it relates to safety surfacing systems focused on the criterion for determining impact attenuation thresholds for the reduction of life threatening permanently debilitating head injuries to children. The study recommended the following:

“ Recommendations for the peak g criterion

Further research is needed to determine the appropriateness of the current 200 peak g criterion in the CPSC guidelines. Furthermore limitations and uncertainties associated with the peak g model for head injury and with the 200 peak criterion include the following:

• The peak g model does not take into account the effects of impact duration, angular acceleration, impact locations other than frontal head impact, and directions of impact other than the anterior-posterior direction associated with frontal head impact.

• The peak g model has not been correlated with the risk of structural or functional brain damage, particularly for children.

• The 200 peak g tolerance limit is based on linear skull fracture data, yet functional and structural brain damage can occur at impact levels well below those produced by skull fracture.

• The 200 peak g tolerance limit is based primarily on adult data, but there are important differences in the skull characteristics and head impact responses of children and adults.”

The study also questioned the 200 g-Max and 1000 Head Injury Criterion (HIC) and its ability to reduce most serious head injuries.

In lieu of the increase in long bone fractures to children ages 5 through 12 the question has been raised as to whether a lower g-Max and HIC threshold would significantly eliminate serious temporary and long term head injuries and concussions as well has reduce the number of long bone fractures. What reductions in these current impact thresholds need to occur to demonstrate a quantifiable decrease in these types of injuries? In 1990 the conventional wisdom within the industry was that most available loose-fill compacted surface systems at a minimum depth of 12 inches would result in a fall impact that would well bellow the current thresholds at a fall of 10 feet or less. With ADA/ABA requirements and increased popularity of unitary surface systems there was a concern with the industry’s ability to deliver compliant surface system solutions that were within the budget realities of most public playground owner/operators.

The last major revision to ASTM F1292 allowed for the development of the first field test instrument whose use would soon begin to challenge manufacturer’s product warranty, installation compliance, and allow the owner/operator to verify their maintenance and surface system compliance throughout the life of the playground. This has led to some initial studies of various surface systems by government granting agencies and an increase in requirements for procurement of surfacing systems to assure standard compliance and protect the owner, designer, manufacturer, and installer prior to the opening of the playground.

There are international standards development organizations and various advocacy groups who have conducted more recent studies that unfortunately are providing inconclusive data that lead to recommendations and conclusions that can only muddy the waters for the industry as a whole. Studies in Great Britain and Australia have stated there appears to be no conclusive evidence that surfacing systems reduce the frequency and severity of injuries from falls to the surface. Some have concluded because of incomplete data or incomplete gathering of pertinent information related to this analysis that only by reducing the fall height can there be any significant reduction of injuries from falls.

I for one do not subscribe to this notion and believe that a well thought out research study that analyzes all the factors related to the cause and effect of falls injuries will show:

• Non-compliant surfacing systems result in serious head injuries and life threatening permanently debilitating injuries.

• Environmental factors outside the scope of the current standard have a negative impact on impact attenuation and will render some surface systems non-compliant

• Compliant surface systems, i.e. 200 g-Max or less and 1000 HIC or less will still result in some statistically verifiable percentage of serious head injuries and permanently debilitating injuries.

• Verifying where the fall occurred and the fall height of equipment from where the injury occurred is consistent with the Standard’s stated fall height of the equipment involved in the injury.

• Reducing the current threshold for establishing the critical height of a surfacing system to 150 g-Max or less and 800 HIC or less will significantly reduce the frequency and severity of both serious head injury and long bone fractures.

Call for Further Research

Only when we can document this information can we begin to address any reduction in serious head injuries and life threatening permanently debilitating injuries plus some reduction in long bone fractures while maintaining a quality educational playground environment without significantly reducing challenge or risk.

How the industry goes about formalizing and developing the scope of this research project will be the next challenge but the largest obstacle to date is who should take the lead and who should fund this project. This should be a multi-disciplined effort capitalizing on research that has just been completed and is currently underway throughout the world. This will take several years to complete if and when research funds can be secured. Children cannot afford for us to procrastinate any longer.

New ASTM F1487-11 Standard released November 2011

Saturday, January 7th, 2012

New ASTM F1487-11 Standard released November 2011
By Kenneth S Kutska, CPSI
Executive Director, International Playground Safety Institute, LLC
Chair of ASTM F15.29 Subcommittee responsible for the ASTM F1487 Standard
November 18, 2011

As Chair of the American Society for Testing and Materials Subcommittee responsible for ASTM F1487 Standard for performance requirements for public playground equipment I am pleased to announce the latest revision of this standard. This revision is over four years in the making and there are several significant additions. You can order this standard online through the ASTM web site ( I might suggest you look into the cost of joining the ASTM and compare the cost of membership to the cost of purchasing this one standard. As a member of the ASTM you are entitled to one volume of the ASTM standards in either a paper or CD version at no charge. The playground standards are located in one of two volumes. The standard would be in either F15.07 or F15.11. Check with ASTM membership services or do a ASTM web site search for ASTM F1487-11 Standard or any other playground related standards to determine which volume is most important to address your needs.

Major Swings Section Revisions

There is a new definition for a swing that should be of particular interest to all of us. A swing is now defined as an element or seat suspended from an elevated support structure, allowing users to move freely in one or more planes, possessing a pivot point greater than 24 in. (610 mm) when measured vertically from the top of the suspended element to the pivot point. This clarifies when a suspended element should comply with all the other performance requirements of swings based on a hazard based analysis. When we think of swings, we envision traditional to-fro belt or bench type swings or a tire swing. We have seen many new products from around the world attempt to enter the market place. While they may be compliant to another international standard, they did not meet the ASTM Standard. Now however, there is some hope. Up until now, we could not clearly and totally evaluate these new swinging products by using the ASTM F1487 Standard. The ASTM F15.29 Subcommittee Working Group responsible for swings took an in-depth look at what the real hazards were regarding swinging components. The new performance requirements are based upon the analysis of injury data related to swinging components. They concluded that swing related hazards were attributable to; falls to the surface, impact with stationary structural components, and impact with the suspended swinging components. Our goal is to eliminate known hazards with the understanding we cannot control how the users may attempt to interact with the play equipment in unintended ways. The Standard now identifies three possible types of swing configurations. They are; single axis (to-fro), multiple axis (rotating), or swings with multiple motions consisting of a combination of single axis and multiple axis (combination swings). Fall related injuries are already addressed in the F1487 Standard by requiring compliance to the ASTM F1292 Standard from the highest pivot point. The next major impact type injury regardless the swing type is from suspended components impacting the user. The new standard addresses this impact hazard through a new “Dynamic Impact Test” procedure that measures impact forces created by the swinging component. This test is intended to be administered by a commercial laboratory. The application of existing clearance zones requirements to any suspended swinging component reduces the likelihood of impact injuries sustained when the user and swinging component comes in contact with the structural members or the adjacent to-fro swing. More on this test method later.

Another concern was the CPSC’s recommendation that multiple occupancy swings not be used on public playgrounds. This recommendation has been around for more than 20 years. There were legitimate concerns based on the injury data gathered over the years but times have changed and the marketplace has introduced many new products. Some argue for multi-occupancy swing seats based on new products introduced in other countries. There does not appear to be any recorded impact injury history from these new products. The dilemma is that the ASTM Standard and the CPSC Handbook allow for multi-axis swings such, as tire swings, and not a multi-occupancy to-fro swing? These multi-occupancy multi-axis swing components (tire swing) move in all directions unlike the predictable to-fro action of traditional single occupancy to-fro swings. Why one and not the other? The explanation might be the fact the swinging component was a tire and somewhat flexible and impact attenuating. The CPSC Handbook even limited the swinging component weight to 35 pounds. This happened to be the average weight of an automobile tire. The real hazard and injury in question is Traumatic Brain Injury (TBI) through impact to the child’s head or body. But what really causes the injury and at what point does Traumatic Brain Injury (TBI) occur? During the October 2011 ASTM F8.63 Subcommittee meeting in Tampa Florida, Rolf Huber, Canadian Playground Advisory Group reported the results of a ten year injury analysis conducted by the NHTSA. The study showed a 10% reduction in TBI and death after a implementing a reduction in automobile industry impact thresholds. This study demonstrates real injury reduction related to a measureable reduction in industry impact threshold used to design automobiles. This study supports our new threshold for the “Dynamic Impact Test” on swinging components and therefore addresses the impact injury to the head and for the most part other body parts. The primary cause of serious impact injuries has always been heavy solid swinging components such as; metal animal swings, bench swings, and the two person glider swings. By implementing the new “Dynamic Impact Test” for suspended swinging components, we can mitigate the impact hazard for any swing component. The logic of this recommendation was of major concern to our group. Head impact injuries resulting from falls to a hard surface should have been addressed through compliance with ASTM F1292 thresholds for impact attenuation of less than 200g and 1000 HIC. These thresholds were not intended to address fractures, but the risk of death from serious head injury. It was unknown at what impact threshold we can achieve a significant reduction in broken bones. Based on the new research related to Traumatic Brain Injury (TBI) we are seeing significant reduction in TBI in automobile accidents. The new swing impact test thresholds more closely follow the National Highway Traffic Safety Administration (NHTSA) automobile safety standards as related to our scope of intended users, especially the pre-school age group, and the results of studies of concussed NFL players during the late 1990s. The standard requires test compliance of all swing seats and swing components located less than 84 inches from the surface during its full range of motion. The test method requires the suspended elements be brought back to a point, 60 degrees from its position at rest, and released to strike an instrumented head form imparting a force less 100 g and 500 HIC.. Mr. Huber’s research of studies on the subject of TBI and bone fractures supports this conclusion for a significant reduction in these types of playground injuries when these new impact thresholds are not exceeded.

The same impact performance requirements for clearance and use zones apply to a traditional single user to-fro single-axis swing-set, with no more than two swings per bay, however multi-occupancy and multi-axis swings have some different performance requirements. Both multi-occupancy and multi-axis swings are limited to one swinging component per bay and have specific clearance requirements related to their designed path of travel. These requirements eliminate impact by adjacent swing elements and their structural components.

The combination swing is a new type of product being introduced around the world. It represents a combination of to-fro and multi-axis swings and is used by more than one person. Taking the same hazard based approach; the Working Group came up with some similar, yet quite different, performance requirements. The clearance and use zone requirements combine the side and overhead clearance zones and use zone requirements for each type of moving (swinging) component. These requirements are too difficult to address in this article without including many illustrations. I suggest that you acquire the new ASTM F1487-11 standard and study that section in detail.

Signs and Labels

The Subcommittee also dedicated a significant amount of time on signs and labels section of the standard based upon recent injury data and requirements for warnings found within the 2010 U. S. CPSC Public Playground Safety Handbook.

The Sign and Label Section of the new standard entails significant changes that should be read very carefully. The new standard states the owner/operator of the play equipment shall be responsible for the content and location of all signs. What does this mean? The information regarding the intended ages of the users shall be provided by the manufacturer, designer, or consultant. The final location of these signs and warnings shall be placed where the manufacturer, designer, or consultant states, however, for lack of any guidance on location for posting these signs, the owner/operator shall place them so they are readily visible to the intended viewer and alert the viewer to the potential hazard in time to take appropriate action. The message may be put on either a sign or a label and be located on the equipment or be freestanding. Freestanding signs must be located outside the use zone. The question for all of us is, “Where do we locate the warnings so the viewer has time to act prior to coming in contact with the hazard?” Currently there is no specific wording for many of the warnings now required. Information communicated on the sign or label, or both, shall address, but not be limited to, the following messages:
• Information message communicating age appropriateness as determined by the manufacturer/designer.
• Information message communicating, at a minimum, supervision recommendation.
• Warning message communicating the removal of helmets, drawstrings or accessories around the neck which are all known to create head entrapment or entanglement hazards.
• Warning message communicating hot play surfaces and/or ground level protective surfacing, when applicable. These surfaces are known to reach temperatures high enough to cause serious burns to children generally less than four years of age but because of the many variables effecting how and when a surface becomes a safety concern it was not possible to find a one size fits all approach that the subcommittee could agree upon.
• Warning message communicating the hazard of play equipment located over hard surfaces, when applicable. This warning message is no longer required to be plastered on each and every piece of free standing equipment.

Specification for all warning signs or labels, or both, should conform to ANSI Z535.1 and either ANSI Z535.2 or ANSI Z535.4 in the following areas: legibility, type of lettering, clarity of message and symbol, color specifications, and word message and visibility. The labels or signs should be durable and conform to UL 969. It has been and continues to be the responsibility of the owner/operator to replace signs or labels, or both, should they become illegible, destroyed, or removed.

The Subcommittee has agreed to continue to work on the Sign and Label Section to seek better solutions, if any can be found. Anybody who is interested in working on this subject may contact me; however membership in ASTM is a prerequisite to be on a Subcommittee’s Working Group. I can forward your suggestions to the appropriate Working Group.

Two New Reference Documents

The Standard has added two reference documents that must be followed by the manufacturer, designer, consultant, and owner/operator. Regardless of the material or the treatment process, the manufacturer/designer/fabricator shall ensure that the users of the playground equipment cannot ingest, inhale, or absorb any potentially hazardous amounts of substances through body surfaces as a result of contact with the equipment. All materials content shall comply with the Consumer Product Safety Improvement Act of 2008 (CPSIA). This Act pertains to, but is not limited to, coatings and substrate of the materials used within the play environment.

As with previous versions of this Standard, this specification does not address accessibility, except as it pertains to safety issues not covered in the United States Department of Justice (DOJ) 2010 Standard for Accessible Design: Title II (28 CFR 35) and Title III (28 CFR 36). This document is available free at: This document is now the law and will be enforceable early 2012. While this document gives us guidance for what constitutes the minimum requirements for accessible design it cannot guarantee we might not have to face a complaint raised by one or more of our constituents. Then and only then will the Department of Justice rule on what, if anything, may need to done to bring a public playground or any public facility into compliance.

In closing, I would like to encourage everyone to get a copy of this new document and read it carefully. That being said I have just three more changes to highlight from the 2007 version. First, for many years we have stated there should be no gaps at the transition of a slide and the slide surface should smooth and continuous. This has been open to unlimited translations by many inspectors. The manufacturers are very aware of the safety concern with entanglements on slides. To take some of this guesswork out of the application of this old requirement we have changed the wording to, “Slides shall be constructed in such a manner as to provide a continuous sliding surface (roller slides exempted) and shall minimize the likelihood of entanglements.” This leaves a lot of the compliance interpretation to the manufacturer/designer so long as the slide is installed and maintained as intended.

Second, we now have a performance test method to determine when a projection increasing in diameter from its initial surface is truly an entanglement hazard. When the projection fits within any of the protrusion test gauges and the increase in size extends greater than 0.12 in. (3.0 mm) from the initial surface with a depth greater than 0.12 in. (3.0 mm) it is an entanglement hazard.

Third, on stairways, all steps greater than 48 in. (1220 mm) above the protective surfacing shall be required to have protective barriers. The height of the protective barrier on a step shall be the vertical distance between the top front edge of a step and the top surface of the protective barrier and appropriate for the ages of the intended users.