Local prohibitions (Singapore, China, UAE Fujairah, several EU/US ports) on washwater discharge from open-loop EGCS.
In practice
Operator publishes a port-by-port scrubber-mode policy. Deck/engine staff verify mode change at boundary entry; logs reviewed at PSC and operator audit.
Regulatory detail & full definition
Local prohibitions on washwater discharge from open-loop exhaust gas cleaning systems. Singapore, Fujairah, and several China ports prohibit open-loop discharge inside port waters; many EU Member States have national or sub-national bans (Germany, Belgium, Spain), and several US states require closed-loop operation. The ban list expands as port authorities respond to scientific concern about scrubber washwater pH, PAH, and metals. Operators monitor port-by-port requirements through OCIMF and BIMCO advisories and switch to closed-loop or compliant fuel inside affected waters.