New results on the aqueous ferrocyanide system at neutral pH are presented here using the coupling of a 10 MeV LINAC with infrared spectroscopy. Seconds after irradiation, we observe a decrease of the Fe(CN)(6)(4-) ferrocyanide ion concentration. Hydroxopentacyano ferrate(III) as well as hexacyanoferrate(III) ions are formed. After a 1500 Gy irradiation, we observe de-aquation of the former species, leading to the latter with a characteristic time of about 410 s and reduction of ferricyanide into ferrocyanide ions with a rate constant of 3 mol(-1) dm(3) s(-1). Berlin green is also detected when the irradiation dose is greater than 2500 Gy. (c) 2006 Elsevier B.V. All rights reserved.