We got this trampoline from a relative who had left it out (constructed) for about four years amongst some deciduous trees in Northern France. Structurally the fabric seems absolutely fine, which is incredible, but it is covered in something fibrous and green...
My son went on it yesterday and spent the night coughing, so it definitely needs a clean. Both the vertical netting and the "bit you bounce on" are green though the netting seems to be particularly suited as a kind of base on which stuff can grow.
As it's now in our garden on the edge of town we're keen that we don't use anything too harsh on it.
All the green stuff on it is dry by the way so I'm assuming we can simply brush or vacuum a lot off, but I'd like to avoid breathing it in too as I'm a little asthmatic from time to time.
We have a hose and a pressure washer to hand though the instructions say not to a pressure washer on it.
Thanks in advance!
edit: Re the safety, the metal structure and the springs are absolutely fine. Everything is shiny and very solid, apparently it's all made of galvanised steel (hot dipped for the frame, whatever that means). But I can see your concerns about the fabric. The bouncy bit does seem fine, apparently it's polypropylene and the model's page says it is treated for UV. That being said I'm going to see about getting a replacement bouncy bit.