Maritime Glossary
NOx
Also known as: nitrogen oxides, nitric oxide, NO, NO₂
Nitrogen oxides formed during high-temperature combustion in marine engines, subject to MARPOL Annex VI Tier I/II/III limits.
Status: ActiveVerified: Source confidence: high (96%)
Full Definition
NOx (NO + NO₂) contributes to smog, acid rain, and eutrophication. Under MARPOL Annex VI Regulation 13, marine diesel engines are subject to: Tier I (installed before 2011), Tier II (2011 onwards, ~20% tighter), and Tier III (~80% reduction versus Tier I) for engines operating in NOx ECAs from 2016. Tier III compliance methods include selective catalytic reduction (SCR), exhaust gas recirculation (EGR), and water injection.
Domain Tags
environmentregulationengineering