Comment on "An explanation for the charge on water's surface" by A. Gray-Weale and J. K. Beattie, Phys. Chem. Chem. Phys., 2009, 11, 10994.

Gray-Weale and Beattie's rationalization of the negative charge observed on the surface of water in terms of accumulation of OH(-) is based on the supposedly uniquely large dielectric decrement of hydroxide solutions [A. Gray-Weale and J. K. Beattie, Phys. Chem. Chem. Phys., 2009, 11, 10994]. We challenge this rationalization and point to another ion, namely fluoride, which has a comparable dielectric decrement and size and which is repelled from the surface of water.