Regulatory Context (Southeast Asia): Exhaust Gas Cleaning Systems in Malaysian Waters

The Port Klang, located on the west coast of Peninsular Malaysia, is one of Southeast Asia’s largest container and transshipment hubs, handling significant international vessel traffic passing through the Straits of Malacca. As the maritime industry prepared for the implementation of the International Maritime Organization’s (IMO) 2020 global sulphur cap, port authorities and shipping operators faced increasing pressure to reduce air emissions from vessels while maintaining operational efficiency. For many shipowners, an immediate transition to alternative fuels was not economically or technically feasible. As a result, Exhaust Gas Cleaning Systems (EGCS), commonly known as scrubbers, emerged as an important transitional emission reduction technology.

Scrubbers are exhaust after-treatment systems installed on ships that remove sulphur oxides (SOx) from engine exhaust gases before they are released into the atmosphere. By capturing and treating exhaust emissions at the source, vessels can continue operating using conventional fuels while complying with increasingly stringent air quality regulations. Under the IMO 2020 regulations, the global sulphur limit for marine fuel was reduced from 3.5% to 0.5%, requiring vessel operators to either switch to low-sulphur fuel, adopt alternative fuels, or install approved exhaust gas cleaning technologies. EGCS systems became a widely adopted compliance pathway because they enabled substantial reductions in sulphur emissions without requiring major modifications to vessel propulsion systems.

In Malaysia, the Marine Department Malaysia restricted the discharge of washwater from open-loop scrubbers through Malaysia Shipping Notices MSN 07/2019 and MSN 08/2019 (a clarification). Ships using open-loop scrubbers therefore need to switch to compliant low-sulphur fuel, or use closed-loop or hybrid systems in closed mode, where the restriction applies. The precise geographic scope should be confirmed from both notices before it is stated.

Scrubbers reduce sulphur oxide emissions from existing vessels and can be retrofitted, which makes them a transitional option for established fleets while other decarbonization pathways develop. They do not reduce greenhouse gas emissions.

This example illustrates the regulatory context for ship exhaust-gas cleaning in Malaysia. The evidence reviewed does not establish a named Port Klang installation or measured port-level outcomes. Any statement about washwater discharge restrictions should cite the applicable Malaysian notices and their precise geographic scope.