Policies from both the International Maritime Organization (IMO) and the European Union (EU) mandate that ship operators reduce the sulfur emissions of their operations. Vessels operating within a Sulfur Emission Control Area (SECA) must either utilize low sulfur distillate fuels or have an approved exhaust gas treatment system installed onboard to capture sulfur emissions.

When operating within SECAs, closed-loop scrubbing is required. To maintain alkaline levels in the scrubbing water, sodium hydroxide (NaOH) in a 50% solution is commonly used, as the pH range of fresh or seawater can vary from 6.5 to 8.5.