No one disputes the benefits of play and recreation, but there is a significant dispute about what an acceptable severity for a play-related injury is. Standards (ASTM F1487, CSA Z614, En1176, SS457, etc.) boldly state that they are to prevent fatalities and then either debilitating or serious injuries. Society, on the other hand, finds it difficult to accept injuries that are in excess of fractures, concussions, lacerations, or any injury that requires medical treatment or takes the injured person away from school or work for more than one day (serious injury, AIS>3).
Manufacturers cling to compliance with the minimums in standards as a defense, while the Designer/Owner/Operator (D/O/O) will be held to society’s acceptance of injury as they negotiate their way through a lawsuit. That lawsuit or inquiry is likely to be the result of a fall and impact with the “protective surface”, or “impact attenuating surface (IAS). Standards are not very helpful in regard to injury reduction and prevention with surfacing since 1000 HIC is an 18% risk of life-threatening, and 55% risk of serious head injury, and 200g is a 10% risk of skull fracture. This leaves the D/O/O in a quandary when designing, installing, and maintaining to the performance in the relevant national standard.
Playspace stakeholders must consider the 3 Es in any playspace they are either designing owning, or maintaining. Stakeholders must avail themselves of the educational opportunities and literature related to playgrounds and playspaces. Recently (the past 20 years), there has been a rise in the use of risk assessment through a “hazard identification and risk assessment (HIRA)”, or “benefit-risk assessment” process as outlined in ISO 4980. People tend to avoid or disregard that a key element to this work is the definition of risk (a combination of the probability of occurrence of harm and the severity of that harm i ) requires them to stipulate the maximum severity of injury. Many organizations have published “safety and well-being” documents that go beyond policing and reduction of criminality. This includes schools and public agencies such as municipalities and licensing and regulators. These are often in conflict with their acceptance of compliance with specific standards. An evaluation of the content of the standards concerning aligning with their own safety or injury prevention policies would be instructive. This is the first E, Education. Failure to investigate and understand injury prevention is at the stakeholder's peril.
Education of Playground Stakeholders
It is incumbent on each and every stakeholder to educate themselves and in turn educate others on the issues related to self-directed play, playgrounds, and the removal of hazards. Some people have a higher responsibility based on their seniority in an organization or their obligations as professionals. Persons, such as Landscape Architects and Engineers have licensing obligations to prevent injuries to the public, and the environment. These people must understand that they will need to understand the intended and unintended uses of the features and equipment associated with the playspace. That could involve the obvious structures and those that might be proximate to the playspace but intended for other use such as sitting or features such as retaining walls. In talking about the merits for regulatory licensing of Landscape Architects, the ASLA Handbook provides:
”Accordingly, regulation creates enforceable competency standards for entry into professional practice and makes disciplinary action a significant disincentive to substandard practice. The research for this report reveals a wide assortment of incidents in which the work of a competent landscape architect would have prevented or significantly reduced the risk of harm, and other incidents where the work of incompetent landscape architecture practice resulted in harm. Regulation discourages or prohibits the practice of landscape architecture by individuals untrained, untested, and unskilled in the profession—in doing so, the public is protected.” ii
The first thing to understand in the education process is that children need to be challenged and encouraged to take on challenges, no matter how difficult. In their effort to achieve, they will fail however their effort should be encouraged until they succeed. Some failures can result in an injury that our medical systems are suited to resolve. Stating the anticipated or acceptable injury is part of the Benefit-Risk Assessment process. The acceptable injury severity should not limit and discourage the attempt through infliction of excessive pain. When a child is encouraged to take on challenges and make play a journey of success, they will try even greater challenges and ultimately become better adults and citizens.
The Key Elements to selection of a surface system and performance will be;
- What the performance requirements of various standards mean
- The characteristics of the surface system, loose fill or synthetic
- The fall height for playground equipment and/or where children will reasonably climb to
- The maintenance requirements for the surface system
- The functional longevity or sustainability of the surface system
Standards set minimum performance, not best practice. In the development of standards, the vested interest of the experts writing them whether manufacturers or owners/operators is driven by their needs and to some extent fears, incorporating the need for the lowest cost to purchase, the least restrictive performance for liability, and ease of administration. The prudent user of any standard must evaluate and be prepared to defend their choices should there be an inquiry after an occurrence of any harm, be it to persons, the organization, or the environment. The impact attenuation limits for all standards around the world are 200g and 1000 HIC. Does anyone think that a 10% risk of skull fracture or 55% risk of a serious and 18% risk of a life-threatening head injury is a Best Practice and not the rock bottom of the Standards Barrel? They are the lowest cost options for buying or maintaining a surface system with injuries such as fractures and concussions that occur on “compliant” surfaces often resulting in large liability settlements.
There are many surfacing systems available to the D/O/O. Generally, those surface systems of lower capital cost have a higher maintenance cost, making the lifetime cost equal or higher than the higher capital cost options. Many of the higher capital cost options provide better-perceived performance for accessibility, however because of cost are installed at their impact attenuation limits resulting in unanticipated injury severity as compared to some loose-fill materials. Although playgrounds are almost always outdoors, the people designing and specifying often forget that UV is detrimental to most synthetic materials. Alternatively, they mix and match materials without consideration of contamination of one material to another reducing the performance of the system. The choices that the D/O/O makes with regard to a surfacing system, must include circumstances affecting performance such as impact attenuation, accessibility, cost, maintenance, functional longevity, warranty content, end of life, etc.
Children are “hard-wired” to climb, and when they climb to and fall from the highest component they are attracted to, there really should not be a question of why did they do it?. It should beg the question of whether “fall height” as listed in standards is realistic. The stipulation of “fall height” is a 5-decades old debate perplexing many who understand that there are serious, severe, and life-threatening injuries on playgrounds resulting from falls and these injuries account for 72-78% of the injuries annually. Mostly the “fall heights” in standards are significantly lower than a child will fall from. At least the Canadian Z614 Standard recognized in 2007 that children cannot fall from platforms/decks when there is a barrier and made the “fall height” the tops of barriers. One theory about the unrealistic “fall heights” in play structure standards, is that increasing the fall heights to a more realistic height would increase the cost of protective surfacing and reduce the money spent on structures or it demands surfacing technology that is not generally available in the market. As a result, the person relying on Standards such as ASTM F1487 or SS457, which intend to prevent the life-threatening and debilitating injury, while requiring compliance with ASTM F1292 (<200g & 1000 HIC) is taking on a problem not of their making. By adopting these minimums they are responsible for when any injury occurs.
The D/O/O that relies on the F1487 and F1292 standards as their minimum performance has likely not examined the ASTM F3313, F3351 or SS495, which guide the D/O/O to consider significantly better performance and therefore lower injury frequency and severity. The ASTM F3351 Standard Test Method for Playground Surface Impact Testing in Laboratory at Specified Test Height, which is also incorporated into the SS495, allows the D/O/O to request the supplier to provide multi-temperature test results for the height they believe a child will achieve in their playground design. They have the opportunity to require that an acceptable surface from that test height must provide g and HIC values below the 200 and 1000 limits. This suggests that the D/O/O understands how their designed play structures will be used under reasonably foreseeable use and has considered the injury severity related to various values of g and HIC. This is translated to the specification for submittals and testing of the installed surface.
ASTM F3313 Standard Test Method for Determination of Impact Attenuation of Playground Surfaces Within the Use Zone of Playground Equipment as Tested in the Field and SS495 provides that a D/O/O can stipulate the “drop height” at any height provided it is greater than “fall height” of the structures. This is where the D/O/O inserts the “specified height” from ASTM F3351. The F3313 and SS495 next allow the D/O/O to set a value for g and HIC provided they are below 200 & 1000. This is where the D/O/O inserts the values they require in the ASTM F3351 testing. SS495 takes this a step further by requiring that every playground surface be impact tested annually provided the g is <150 and the HIC is <700. Once either of those values is exceeded, the surface is to be tested twice per year, with the end-of-life preparations being at 175g or 850 HIC and the closing of the playground at 200g or 1000 HIC. Field testing is the key to compliance and understanding that the impact attenuation performance is maintained.
Every surfacing system needs maintenance, some more than others. A maintenance-free surface does not exist. Obviously, loose-fill systems will need regular and frequent inspection and maintenance, particularly those that are intended to be accessible. Where loose-fill materials are being used for accessibility, the D/O/O must inform themselves of all of the performance requirements for running, cross-slopes, and changes in vertical height. Synthetic surfaces are not immune from complaince to accessibility when it comes to impact attenuation, gaps, and changes in vertical height. Synthetics also often suffer from UV degradation, often due to the type of polyurethane binder that is used. Being porous, synthetics, like poured-in-place, often become filled with sand or harbor vegetation, like moss that reduces the impact attenuation and these contaminants will need to be physically removed. Synthetic turf systems will have to be monitored for depth of infill. Shifting or loss of infill reduces the impact attenuation properties, changes slopes, and also makes it significantly more difficult to traverse with a mobility device. The D/O/O should be looking at developing a budget for the cost of maintenance over the anticipated life of the playground to ensure that there are adequate funds for the required maintenance to ensure the success of the playground over the next 20 to 30 years.
Today sustainability is, rightly so, the latest catchphrase and rarely applied to playgrounds. This can no longer be avoided as it relates to life-cycle and functional longevity, particularly with poured-in-place and tile surfaces failing and ending up in landfills long before the play structure end of life. Claims on the part of surfacing suppliers that they are recycling tires, whereas they are only diverting them to playground use for a few years before going to a landfill do nothing for sustainability. The D/O/O must write specifications and warranties that require suppliers to provide functional longevity and better financial asset management. The SS495, ASTM F3351, and ASTM F3313 can all be used to demand better performance by setting drop heights higher than the minimum fall heights with lower values for g and HIC both at the time of installation and during the 5-to-10-year warranty for the surface. How does it look when a seven-year-old playground must be fenced because the agency does not have the funds to replace a failed surface and the structures are fine?
The D/O/O must educate themselves on the issues related to playground protective surfacing. Failure to specify, install, and maintain surfacing that prevents injuries and provides functional longevity places the D/O/O and their suppliers at risk when an injury occurs. First is the knowledge that the severity of the injury could have been reduced and secondly, there is the potential financial and reputational loss associated with an action taken as a result of the injury.
Engagement with Play
Now that we have convinced everyone that they must be cognizant of the potential for injury and the need for financial asset management and functional longevity we move on the to need for playgrounds to be innovative, challenging, and stimulate the inner child to take on the world. That will take them higher and convince them they can do anything. This is the importance of Play. A self-directed activity is suggested by the playground equipment, the contouring of the surfacing, and the child’s imagination. These are the hallmarks of uninhibited Play. The playground should only be restricted by the ability of a child to temporarily not dominate a graduated challenge presented.
How many playgrounds are there that are covered with children on opening day and soon revert to a ghost facility as children return to their electronic games? With all the benefits of outdoor play; fresh air, physical activity, interaction with one's peers, learning about how your body meets and beats a challenge, mental and social achievement through engagement, etc., why are these children content to be attracted by sedentary activities? Could it be the playground is boring?
What does the electronic game provide on an ongoing basis? Levels!!! Graduated Challenge!!! Being able to Fail and Recover!!! Interactive Play with others!!!, No Parental Direction on How to Play, etc. These features keep children glued to their devices for hours on end. How does the (D/O/O) bring the excitement of the electronic device to the playground? We need to study the features of the games.
Can a playground provide levels with graduated challenges that children will return to again and again? That depends on the ease at which the challenges are achieved. Simply climbing to a slide, no matter how high, is only a climb and a slide and not much challenge. Once the child goes down the slide, where is the next challenge or level? The alternative is to provide a series of activities that raise the level of challenge with each achievement. Adding the perception of risk or danger adds to the excitement. This could be through climbing the outside of a tower or slide or some other activity that suggests risk. Statistically, the greatest risk that children take is one with the potential of a fall. This will involve climbing and height.
Recently mounds, hills, spheres, and play berms have been introduced as play features and not just modulations of the surface. These often contain slides, climbing holds, nets, etc. that are embedded into the surface or extend between the features with the challenge of entering or exciting while traveling up or down. The direction of travel and choices are up to the child. Now we have Self-Directed Play. Adding the risk of falling when challenges are not met is a positive feature.
Failure and recovery are a major feature of gaming. This can also be incorporated into the successful playground. Designers know where their designs have the greatest risk of falling and therefore injury. Designers have the opportunity to feature better-performing surfaces in these areas. This may mean raising the drop height and/or lowering the values for g and HIC. The current suite of standards can be used as a tool to achieve this perception of risk with reduced opportunity for harm that is not acceptable. For years it has been known that activities with upper body structures are a high risk of falling and a location where serious and severe injuries occur. To date, designers have avoided making the better impact attenuation of the protective surface an integral part of that play. Failure to integrate the performance of the surface with the perceived risk of the activity will continue to cause children to go to their electronic devices and unreasonable injuries continue to be inflicted at known areas of severe injury.
There are enthusiastic D/O/Os that provide exciting play places. These are rare and generally found in high-profile or destination sites. Many are as much an attraction to adults as they are for children defeating the playground being a place for children to explore without the helicopter parent. It is often the case that parents will succumb to the begging of children to go down the slide with them, thus avoiding the achievement of completing the activity by themselves. This is not helping the child build self-esteem and likely leads them to constantly count on the adult to solve a problem rather than problem-solve themselves. Sometimes when the child goes down the slide in the parent’s lap, the result is a broken leg for the child. Double failure. Parents can be a child’s worst enemy. It is up to the D/O/O to ensure they understand the reasonably foreseeable use of the people going to the playground and either setting barriers or signage that clearly defines the hazards that still exist even after risk mitigation measures have been taken. This might encourage children to take on greater challenges.
It goes without saying that any discussion about play must include the presentation of play opportunities for people of all abilities. This does present the D/O/O with challenges that go beyond the traditional playground. Being inclusive is a state of mind on the part of the Designer and willingness by the Owner/Operator to ensure the activity areas are well maintained and people of all abilities are encouraged to engage with each other. This will involve the need for site amenities such as parking, accessible routes from the parking lot to the play area, washroom facilities, water fountains, etc.
Play People are good at understanding graduated challenges, with inclusion taking into consideration the various types of abilities and disabilities that would participate in the playspace and provide a range of activities that keep all children engaged. Sometimes people are concerned that the inclusion of physically challenging activities is being disrespectful to those with different abilities, however, the exclusion of these features is disrespectful of those with the ability to tackle the challenge. There also needs to be consideration that there are children in the playground that do not have a disability, however, the caregiver may have a disability and needs access to provide appropriate supervision.
One caution that the D/O/O must be aware of is that traditional playgrounds are generally intended dimensionally and developmentally for able-bodied children 2-5 years and 5-12 years of age. These playgrounds are often designed with physical barriers that the younger age group cannot pass until they master additional skills. Removal of architectural barriers to provide ease of access to children of all abilities can result in children getting to heights that put them at risk of unacceptable injury, usually from a fall. The D/O/O must consider this in the their initial designs.
When it comes to the removal of architectural barriers, often the knee-jerk reaction is to jump to poured-in-place surfacing and leaning heavily on the minimum requirements of the ADA. That means installing a surface that just meets the minimum requirements for ASTM F1292 in the ASTM F1487 Use Zone. This does provide a surface that is firm and stable for mobility devices and those with other mobility issues, but it does not recognize that many of the participants in the space could have greater difficulty in success with some of the challenges. Therefore, the D/O/O must consider the injury prevention performance of the surface as well as the firmness and stability. This may mean a more flexible surface or where the choice is EWF, one that is well-knit and constantly maintained, to both provide excellent impact attenuation and the continued ability to be traversed. This is where the Designer must fully understand the properties of the surfacing materials and write a very good specification, followed by the Owner/Operator providing the maintenance and rejuvenation that keeps the surfacing function as it was originally installed.
Enforcement of Standards and Specifications
The foregoing is all theory unless the Owner/Operator are not only committed to being educated on the issues related to playgrounds, engaging enthusiastic Designers, but most importantly Enforcing compliance with their Specifications, Warranties and Standards. Most “white elephant” playgrounds are those that never fulfill the original intent either at the time of installation or during the functional life of the project. Most of this is due to lowering of performance requirements or not enforcing the stringent requirements of the specification. Every Designer/Owner and Operator have the opportunity to educate themselves or hire specialists capable of writing performance specifications and warranties coupled with a testing program that ensure successful compliance or replacement at no cost by the original supplier.
The ability to test playground surfacing to either the determination of Critical Height or the Specified Height in the laboratory has existed since the late 1980s. During the 1990s the “free-fall test method” was stringently scrutinized and incorporated into ASTM F1292 in 1999 and embraced throughout the world. This test device is now fully described in both the ASTM F355-24 and ISO 24667. Field Testing has been advanced at ASTM with F3313, in Canada through periodic field testing in CSA Z614-20 and most significantly in SS495, which requires testing of all installed playground surfacing at a minimum of once per year.
The field testing in all of these standards is similar and therefore the procedure from specification and warranty, including submittals for the specified height test, field testing at the time of installation and throughout the life of the playground will be discussed. Keep in mind that we will not be using the minimums of the standards, but the allowance to demand better performance that meets the needs of the O/O. We will work to make this generic to allow for easy adoption.
The first element of the Specification is to define the type(s) of surfacing to be installed. For Poured-In-Place there is a standard at ASTM, F2479-24, Standard Guide for Specification, Purchase, Installation and Maintenance of Poured-In-Place Playground Surfacing, while Singapore has Annex B in SS495, Poured-in-place (wet pour/cast-in-situ) surfacing systems. These describe problems that can occur and offers some solutions for consideration in the design and installation of the PIP systems. This is particularly important in Singapore since approximately 80% of the installed surfacing is PIP. Where the desire is to install a loose-fill material ASTM does have F2075, Standard Specification for Engineer Wood Fiber for Use as a Playground Safety Surface Under and Around Playground Equipment, and F3012, Standard Specification for Loose-Fill Rubber for Use as a Playground Safety Surface under and around Playground Equipment. Unfortunately, there are no standards for loose-fill sand or gravel for playgrounds. It must be remembered that most standards for these materials are for road building and compaction, while playground surfacing must be the exact opposite with relatively uniform size distribution of the particles and being rounded to allow the materials to move in relation to each other when a falling object lands of them. The caution is that these materials tend to break down with use which will change the size distribution and reduce the ability of the system to absorb impacts over time. Lastly, for those wanting to have an indication of the firmness and stability of a surface for accessibility, there is ASTM F1951, Standard Specification for Determination of Accessibility of Surface Systems Under and Around Playground Equipment. It is important that the O/O obtain the results for part A (firmness) & B (stability) and a copy of the installation instructions the supplier gave the laboratory for preparation of the test sample. This installation procedure must be incorporated in the specification and not deviated from for the installed surface, or the results are likely to not be the same.
What is the difference between the old ASTM F1292 which determines “critical fall height” whereas ASTM F3351 allows for the three-temperature testing of ASTM F1292 to be performed at a “specified height” and the result reported? Traditionally D/O/Os have specified a surface with a “critical fall height” equal to or greater than the equipment “fall height” to be installed and with the standard construction 1-year warranty. The skilled installed in a low bid situation will be able to meet the specification, including the warranty, with the surface failing shortly thereafter, leaving the O/O holding the bag on replacement. Thus, using F1292 in a specification is asking for the installation of a failed product and being paid for it. This is not the fault of the supplier/installer as they are placed into a competitive low-bid environment. This is the fault of the Designer/Specifier and where cost for failure is to be assigned. You can refer to the ASLA Licensure Handbook.
The ASTM F3351 or sections 4.3 & 9.4 of SS495 are the Specified Height Test. This test allows the D/O/O to evaluate impact attenuation performance of surface systems. How a D/O/O determines the selection of the “specified height” and the maximum allowable impact values for g and HIC can be found in Appendix A of SS495 or on the web at Specified Height Test (thinkific.com). The thinking process and procedures are extensive and well presented in either of those resources and will not be provided for here in detail.
It must be remembered that the goal of this specification is to force surface system providers to install a surface that will not fail and needs replacement for 15 to 20 years. As a result, the “specified height” should be significantly above the structure fall height. This is also likely more realistic as to where children will fall from. In the case of Singapore and a good practice is to require that the g value be <150 and the HIC value be <700 to allow for testing only once per year. Therefore the submittal reads;
The supplier shall provide “specified height” test results for a drop height at least 1m (39”) above the equipment fall height and the value for g shall not exceed 150 and the value for HIC shall not exceed 700.
This is then transferred to the testing of the installed surface using either ASTM F3313 or sections 4.4 and 9.1 of the SS495 by stating the following;
The installed surface is to be tested with a device conforming to ISO 24667 from a drop height of 1M (39”) above the equipment fall height and the value for g shall not exceed 150 and the value for HIC shall not exceed 700.
Long-term performance is ensured through the warranty and the annual testing. The warranty shall be for a minimum 5-year period. The testing during the warranty is again as per either ASTM F3313 or sections 4.4 and 9.1 of SS495 and read as follows;
For the first two years of the five-year warranty period that surface will be test with a device conforming to ISO 24667 from a drop height of 1M above the equipment fall height and the value for g shall not exceed 150 and the HIC shall not exceed 700.
For years 3 to the end of year 5 of the warranty period, the annual testing shall be performed with a device conforming to ISO 25667 from the fall height of the equipment and the value for g shall not exceed 150g and the HIC value shall not exceed 700.
The D/O/O can select higher specified heights for submittals and drop heights for field testing coupled with lower values that they choose.
This provides better injury prevention, based on the automotive risk of head injury. It will also force supplier/installers to provide surface systems that will have a 15–20-year functional life rather than the current 5 to 7. It also allows the supplier/installer to provide a competitive price to a well-written specification that is enforced. This is fair to the supplier/installer, the D/O/O, and the user of the playground.
Sadly, there will be circumstances where a surface does not meet the requirements at the time of installation or during the warranty period. It is incumbent upon the Owner to enforce the specification and warranty to the letter to continue to encourage those meeting the specification to continue to do so and send a clear message to those working to enter the industry a clear message as to specifications and compliance.
Conclusions
This has been a long article. Some of it might be fluff and hyperbole. Please accept our apologies for that. We trust that the reader will understand that surfacing systems under and around playgrounds are complex. With the introduction of mounds, this complexity will only increase. There is a lot a stake. There is the cost of the surfacing and the consequences of a premature failure both in financial terms and the severity of injury that can occur. We wish everyone embracing the concepts of lower frequency and injury severity and increased functional longevity all the best in your future projects.
