There's a couple of things a bout putting used investment in the
garden.
And for me, there’s another consideration I can’t quite get out of my
mind. Used investment, like new investment, still containes
respirable crystaline silica as a major componant. When it’s wet, or
all set up, that’s pretty much contained. But once you add it to
soil, if it dries out, then it’s again a dust that can be kicked up
into the air and breathed in. This isn’t house dust, folks. I’m not
sure I’d want to be putting it in my garden, even if that is outside
and thus ventilated. Were I out there with the tiller, or just
pulling weeds, in hotter drier weather, I’m not convinced that
investment in the compost wouldn’t then be a hazard… Now, tiny
dilute amounts likely are not a problem. No doubt such stuff is
already in normal dust. But using this as an additive, intentionally,
to soil or compost, could give you much higher concentrations of
crystaline silica in your soil or environment that would normally be
there, I would think…
Peter Rowe