Results are presented from laboratory experiments that examined the ability of dilute aqueous solutions of polyfethylene oxide) (PEO), a soluble drag-reducing polymer, to suppress spontaneous vapor explosions of molten tin. Polyfethylene oxide) with an average molecular weight of 4 x106 was used to prepare aqueous solutions with polymer concentrations from 10 weight parts per million (wppm) up to ≈525 wppm, with resulting solution viscosity ratios of 1.01 ≥ ηr ≥ 2.00 at 25°C, where ηr = ηsolution/ηwater. Twelve-gram masses of molten tin at temperatures of 600, 700, 800, 900, and 1000°C were poured from a height of 60 cm into a cylindrical Plexiglas vessel (12.5-cm i.d.) containing 1l of coolant solution at 25°C. The experiment was repeated ten times with each solution to check consistency and repeatability. The maximum pressures recorded for each experiment are reported and are used to compare the relative violence of spontaneous vapor explosions in each solution., Experiments with pure water were carried out to provide a reference of comparison for the polymer solutions. The peak pressures measured in the most dilute PEO solutions (1.02 ≥ ηr ≥ 1.13) spanned a much wider range than those for water, and pressures many times larger than any recorded in pure water were recorded—up to 240 kPa. When the solution viscosity ratio was 1.25 or larger, however, spontaneous explosions were markedly suppressed; above ηr = 2.00, they were entirely eliminated.