What does USP24 Grade mean?

[soflaguy]

Just curious as to what USP24 Grade means? I see this on things like liquidex, ox/var, and few other "research-only" type chemicals.
I know it has to do pharmaceutical quality, but does it mean this is the highest purity?

 

[WormAAA77]

Don't quote me on this but I think USP 24 means that the lab assay came back as >98.5% in terms of purity. USP 25 would be the highest grade possible and I'd imagine it'd mean 100% pure.

 

[baryon]

it's just a protocol. the USP part means it's food grade generally.

--baryon