When designing a playground, safety is the top priority. The surfacing material beneath play equipment plays a critical role in protecting children from injuries, particularly from falls, which account for over 200,000 playground-related emergency room visits annually for children aged 14 and under in the U.S.. While loose-fill materials like sand, mulch, pea gravel, and wood fiber (including engineered wood fiber, or EWF) are commonly used due to their affordability, they come with significant safety concerns that make them less than ideal for ensuring a safe play environment. Let’s explore these materials and highlights their specific safety issues for children, helping parents, educators, and playground designers make informed decisions.

1. Sand

Sand is a traditional playground surfacing material valued for its low cost and natural aesthetic. However, its safety limitations make it one of the least reliable options for modern playgrounds.

Safety Issues for Children:

– Inadequate Fall Protection:

Sand requires a minimum depth of 12 inches to provide adequate impact attenuation for falls, but it compacts over time, reducing its cushioning ability. For falls exceeding 5 feet, sand often fails to meet ASTM F1292 standards for impact attenuation, increasing the risk of serious injuries like concussions or fractures

– Inconsistent Surface Stability:

Wet sand becomes firm and less shock-absorbent, while dry sand is loose and prone to displacement, creating uneven surfaces that can cause tripping hazards or puddles.

– Choking and Ingestion Risks:

Young children, especially toddlers, may ingest sand or put it in their mouths, posing a choking hazard or risk of gastrointestinal issues.

– Hidden Hazards:

Sand can conceal dangerous objects like broken glass, animal waste, or sharp debris, increasing the risk of cuts or infections.

– Poor Accessibility:

Sand is not compliant with the Americans with Disabilities Act (ADA) because it shifts underfoot, making it difficult for children using wheelchairs or mobility devices to navigate.

– Environmental Contamination:

Sand can become contaminated with pesticides or other chemicals from nearby agricultural or urban runoff, which children may ingest or absorb through skin contact.

– Maintenance Challenges:

Wind and foot traffic displace sand, requiring frequent raking and replenishment to maintain depth, which is often neglected, compromising safety.

2. Mulch (Wood Chips or Bark Mulch)

Mulch, often made from shredded wood or bark, is a popular choice for its organic look and affordability. However, it poses multiple risks that undermine its suitability for playgrounds.

Safety Issues for Children:

– Splinters and Sharp Edges:

Mulch can contain rough or sharp pieces of wood, leading to splinters, cuts, or abrasions, particularly for young children who crawl or fall frequently.

– Inadequate Impact Attenuation:

While mulch can provide shock absorption at a 9-inch depth for falls up to 7-10 feet, it degrades over time, losing its cushioning properties. Regular topping-off is required to maintain safety, but this is often overlooked.

– Choking Hazard:

Small wood pieces can be swallowed by young children, posing a choking risk.

– Mold and Insect Infestation:

Mulch can harbor mold, fungi, or insects in moist conditions, potentially causing respiratory issues or allergic reactions in children.

 

Like sand, mulch can conceal hazards such as glass, rocks, or animal feces, increasing the risk of injury or infection.

– Non-ADA Compliant:

Mulch does not meet ADA standards for accessibility, as it is difficult for wheelchairs or crutches to navigate, limiting inclusivity.

 

Mulch fades, breaks down, and scatters with use, requiring regular raking, debris removal, and replenishment to maintain safety and appearance.

3. Pea Gravel

Pea gravel, consisting of small, smooth stones, is often chosen for its natural appearance and drainage properties. However, its safety drawbacks make it unsuitable for most playgrounds, especially those with higher equipment.

Safety Issues for Children:

– Limited Fall Protection:

Pea gravel requires a 9-inch depth to protect against falls up to 5 feet, but it is ineffective for higher fall heights common in modern playgrounds, increasing the risk of head injuries or fractures.

– Choking and Ingestion Hazards:

The small stones are a choking risk for young children who may put them in their mouths, noses, or ears.

– Thrown or Kicked Stones:

Children can kick or throw pea gravel, posing a risk of eye injuries or harm to others.

– Hardening in Cold Weather:

In colder climates, pea gravel can harden, reducing its shock-absorbing capacity and increasing injury risk.

– Poor Accessibility:

Pea gravel is not ADA-compliant, as it shifts underfoot, making it nearly impossible for children with mobility devices to use the playground safely.

– Hidden Hazards:

Like sand and mulch, pea gravel can hide sharp objects or debris, increasing the risk of cuts or infections.

 

Pea gravel scatters easily and requires regular raking, inspection for debris, and replenishment every few years to maintain depth, which can be labor-intensive.

 

4. Engineered Wood Fiber – (EWF)

Engineered wood fiber (EWF) is a processed form of wood designed to interlock and reduce splinters, making it a step up from standard mulch. While it’s often marketed as a safer alternative, it still has notable safety concerns.

Safety Issues for Children:

– Degradation Over Time:

EWF breaks down with use and weather exposure, reducing its impact attenuation and requiring frequent topping-off to maintain a 9-inch depth for falls up to 10 feet.

– Mold and Insect Risks:

Like mulch, EWF can develop mold or attract insects in damp conditions, posing health risks such as respiratory irritation or allergic reactions. 

– Choking Hazard:

Small pieces of EWF can still be ingested by young children, presenting a choking risk, though less severe than with standard mulch.

– Hidden Debris:

EWF can conceal hazards like glass or sharp objects, increasing the risk of injury.

– Limited Accessibility:

While EWF is sometimes marketed as ADA-compliant when compacted, it often becomes uneven or loose in high-traffic areas, making it challenging for wheelchairs or mobility devices to navigate.

 

EWF requires regular raking, debris removal, and replenishment to maintain safety and accessibility, adding to long-term costs and labor.

– Potential Chemical Exposure:

If not sourced from untreated wood, EWF may contain chemicals like chromated copper arsenate (CCA), which is toxic and inappropriate for playgrounds.

Why These Materials Are Considered Unsafe

The primary safety issues with sand, mulch, pea gravel, and wood fiber stem from their inability to consistently provide adequate fall protection, their propensity to harbor hidden dangers, and their lack of accessibility for all children. These loose-fill materials often fail to meet modern safety standards, such as ASTM F1292 for impact attenuation or ADA requirements for accessibility. Additionally, their high maintenance needs mean that safety is often compromised when upkeep is neglected, which is common in public playgrounds with limited budgets. The Consumer Product Safety Commission (CPSC) recommends at least 12 inches of loose-fill materials like sand, pea gravel, or wood chips, but even at these depths, they may not protect against falls from higher equipment.(https://www.cpsc.gov/safety-education/safety-guides/playgrounds/public-playground-safety-checklist)

Moreover, these materials pose unique risks to young children, who are more likely to engage in behaviors like putting objects in their mouths or crawling on the ground, increasing exposure to contaminants or choking hazards. Unlike unitary surfaces (e.g., poured-in-place rubber or rubber tiles), which offer consistent cushioning and accessibility, loose-fill materials degrade, scatter, or compact, creating uneven and unsafe surfaces over time (https://www.eenews.net/articles/toxic-chemicals-lurk-at-childrens-playgrounds/)

 Safer Alternatives

To create a safer playground, consider unitary surfacing options like:

– FallZone Poured-in-Place (PIP) Rubber: Offers excellent impact attenuation, durability, and ADA compliance.

– FallZone Synthetic Grass with Envirofill Infill: Combines aesthetics with safety, excellent impact attenuation, durability, and ADA compliance.

If loose-fill materials are unavoidable due to budget constraints, engineered wood fiber is the least problematic of the options discussed, regularly maintained, and sourced from non-toxic wood. However, even EWF requires diligent upkeep to remain safe.

Sand, mulch, pea gravel, and wood fiber may seem like cost-effective playground surfacing options, but their safety issues—ranging from inadequate fall protection and choking hazards to poor accessibility and high maintenance demands—make them risky choices for children. Playground designers and caregivers should prioritize surfaces that meet ASTM and ADA standards while minimizing health and injury risks. By investing in safer alternatives like FallZone Poured-in-Place Playground Surfacing or FallZone Synthetic Grass Playground Surfacing, we can ensure playgrounds remain fun, inclusive, and, most importantly, safe for all children.

For more information on playground safety, consult the U.S. Consumer Product Safety Commission’s *Public Playground Safety Handbook* or contact a certified playground safety inspector. Let’s keep our kids safe while they play