Engineered wood fiber (EWF) can attract fungus that can effectively knit together the upper wearcourse of a playground, creating a semi-solid mass that no longer provides the disbursion necessary for initial fall impact attenuation, which reduces the safety greatly. This fungus is normally white and very thick, while beneficial in nature, it is not good for playground safety surfacing. The EWF has to be removed and replaced because it cannot be restored to provide the fall safety it is intended to provide, protecting children in the event of a fall impact.
In this particular playground of 5,000 sqare feet, the entire surface was like this as one solid mass, a child rode their bicycle out onto the playground, and stomping on it made little particles bounce about 6 to 8 feet away. Heat, air and moisture are the perfect breeding ground for microbes, whether mold, mildew, fungus or bacteria. None of which are really good around playgrounds, and studies have reported they have over 2,000x more bacteria than a public bathroom doorknob.
EWF attracts more than microbes, it also attracts bugs, rodents and other critters, to name a few. You know termites like wood, right? They love EWF, and so do lots of other bugs. You normally use wood shavings for the bottom of a mouse or rat cage? Yeah, they love to nest in wood fiber. Guess what likes rodents? Yep, the founder of this company found a snake living in the EWF at a playground, because rodents were nesting there, too, and it didn't need to go anywhere else for food. So much life living within the playground safety surfacing!
Yes, fungus knits together the "wood wide web" that allows trees to communicate and share nutrients with each other, and it can and will destroy the fall safety of any infected wood-based playground surface like EWF. At this point, what's beneath is normally broken down into a fine powdery dust, which provides no real fall impact protection, so the entire surfacing hs to be replaced. Removing and replacing 12" of EWF is not easy, the NRC recommends doing it every two years, with frequent churning and re-topping required, which leads to the question: "why did someone choose this for playground surfacing?"