Thats interesting
I have a feeling I know what you're talking about, but I've never heard it used in that application
its a bit more resilient than kitchen cutting boards
![Hammer :hammer:](https://board.marlincrawler.com/Smileys/marlin/hammer.gif)
but it is commonly used as fire engine water tanks now, due to its durability, and lack of weight. That is what is what I woudl guess they are using . I don't know what it is called, but that may give you something else to search for. You can actually weld it too, they've got plastic welding rod for it and everything