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Zinc runoff rates from 11 zinc-based construction materials with and without surface treatments or coatings are presented and discussed in terms of patina formation, seawater deposition, wetting conditions, and changes in corrosion resistance. As opposed to earlier reports, current runoff rates have been assessed in a marine test site ͑Brest, France͒ rather than in mainly urban sites. High surface wetting conditions and concomitant removal of deposited chloride and sulfate species are proposed to cause the unexpectedly low zinc runoff rates observed in the marine site, despite a high ISO corrosivity classification for zinc. The average runoff rate for hot dipped galvanized steel after 1 year is 2.9 g m −2 year −1 and 100 times lower when coated with two organic layers ͑150 m͒. Organic coatings of varying thickness ͑1-150 m͒ result in improved barrier properties and reduced runoff rates that seem highly dependent on thickness. Aluminum alloying also results in reduced zinc runoff rates caused by surface areas enriched in aluminum.The environmental concern related to the diffuse emissions of metals from various sources in the society has become an important issue in environmental risk assessments and the development of policies and restrictions toward the use of metals and metal alloys in external applications. Due to lack of data, these restrictions are often based on the precautionary principle and conservative deliberations. An increased understanding of the mechanism, the extent and the fate of corrosion-induced zinc runoff is of outermost importance for sustainable actions toward the use of zinc in external applications in the society.Several studies have estimated and monitored metal flows from various and combined sources in the society into urban storm water systems. 1-3 Metals are dispersed from many different sources including external constructions and the traffic sector as main sources for zinc. 3,4 Quantitative data of corrosion-induced runoff rates from zinc-based materials used for construction have during recent years been acquired in parallel field and laboratory studies, mainly relevant for urban conditions. These research activities have mainly aimed to fill knowledge gaps related to, e.g., differences between corrosion rates and runoff rates, 5-7 environmental and material parameters that govern the zinc runoff process, 8-10 and to elucidate the environmental fate of zinc runoff. 11,12 However, data and knowledge of the influence of chloride deposition in marine environments on corrosion-induced zinc runoff from zinc-based construction materials are still limited. 10,13 The aim of this paper is to provide a comprehensive picture of the zinc runoff process on bare zinc sheet, and different zinc-based materials and alloys with and without surface treatments, or organic coatings, when exposed at unsheltered conditions in a chloride-rich marine environment for 1 year. The study comprises continuous runoff rate measurements of zinc, combined with corrosion rate measurements, multianalytical surface s...

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