Folks, I didn't ask for advice about disposal. I don't want to hash through why or how I decided to take it to the waste disposal site. That decision has been made and I'm not pouring the stuff into my septic tank, thanks anyway.

I want to know if it is okay to mix used sodium thiosulfate with used acidic ammonium thiosulfate while awaiting disposal. It is a chemistry question: will I produce sulfur dioxide or is it fine?

Sorry... didn't mean to touch off a firestorm of disposal opinions.. I actually thought it was a simple question! I'll try to ignore the stereotyping based on where I live. Wow.

Ned