Italian to English Science Chemistry; Chem Sci/Eng antioxidants

I've got a list of oxidising agents: anione superossido, radicale idrossile, perossido d'idrogeno, acido ipocloroso, radicale per ossidrile.
Initially I thought that "radicale per ossidrile" must be a synonym of "radicale idrossile" (i.e. hydroxyl radical), bearing in mind that idrossile and ossidrile are synonyms, and they'd simply made a mistake by including it twice. However, the only link I've found for "radicale per ossidrile" includes it in a table of redox potentials and gives it a different value to that indicated for "radicale ossidrile" (1.25 against 2.06): page 2 of
http://www.provincia.belluno.it/Natura/Studi/WCRSA/Relazione...

Has anyone any ideas what it actually is?