Copper dust formation was observed in the distillate channels of all of the heat recovery stages constructed with 90/10 Cu/Ni material in Al-Hidd MSF units, which is a recently constructed plant in the Kingdom of Bahrain. No copper dust was observed in the stages constructed with the 30/70 Cu/Ni material. Chemical analysis of the collected metal dust confirmed that copper is the main constituent. A possible source of the dust is the disturbance of the equilibrium in the 90/10 Cu/Ni alloy as a result of a combination of the operating conditions and chemicals present in the seawater. In addition to CO2, which may be produced by thermal decomposition of bicarbonates, pollutants which may be present in the intake water could be the sources of the detrimental chemical.