I don't like carpet padding foam insoles anymore - where get other foam?

[tstop4me]

Sounds right.

Problem is, AFICT, podiatrists typically commonly use polyurethane foam as the liner when making orthotics - because it is very durable. So that's what I wanted to imitate.

If you're really concerned about skin contamination, you can stick a layer of moleskin on top of the foam liner.  The Dr. Scholl's and Curad brands last at least a year under my skating conditions (5 sessions/wk; 1.5 hrs/session; almost yr round).  When the moleskin wears down, and if the underlying foam is still good, you have two options.  With some foams, you can strip off the moleskin without damaging the underlying foam, and apply fresh moleskin.  With other foams, you can't.  In which case, since the moleskin is thin and squishy, you can simply stick a second, fresh layer of moleskin on top of the first, worn moleskin.  When the second layer of moleskin wears down, you can strip it off the first layer, and apply a fresh layer.

[Query]

I wonder how much safety a layer of moleskin actually provides on top of a carcinogenic foam. Maybe a little bit of the foam might turn to powder, and touch the foot.

[Leif]

Is polyurethane really carcinogenic to the degree that the small amount in an insole would pose a measureable threat to one's existence and/or health? I could understand taking extra precautions when using polyurethane varnish for example, or for workers in a factory making sofas filled with PU foam. And of course PU is all around us in various forms.

As an aside, alcohol is carconogenic, but most of us ignore that fact. And pesticides look to be more toxic than once thought. Some of us grow our own veggies though. 

[Query]

I don't know exactly how dangerous it is. I'm sure it depends on the specific foam.

I'm not sure it is the polyurethane itself that is carcinogenic - I think it is the chemical agents that form it and make it foam. In fact, many orthotics use polyurethane as the top layer - but I believe they use special, skin-safe foams that are formulated for the purpose.

[tothepointe]

You could try with cork then. Though the contact cement you'd need to stick together the layers is not the safest thing in the world. Shoes, in general, are pretty toxic. It's why I dropped it as a hobby. A combination of all the solvents then having all that dust ending up in my house and nose and everywhere.