Soot-related pollution linked to Inert Gas Systems/Generators (IGS/IGG) and open-loop scrubber operations is no longer a minor nuisance. It is increasingly a regulatory, financial, and operational disruptor, triggering delays, clean-up orders, fines, and—at the sharp end—vessel detention. West of England reports 60+ documented incidents, while the true scale may be higher.
Why the risk curve is steepening
Environmental enforcement is becoming more intrusive and punitive, and several ports/coastal States ban open-loop operations altogether. The paper highlights strict and highly visible enforcement in jurisdictions such as Turkey and the UAE. Fines can range from a few thousand dollars to millions, with Club experience of cases exceeding USD 1 million for serious incidents.
Where soot and “black water” actually come from
1) Inert Gas Generators (IGG): soot from incomplete combustion
IGGs are critical for tanker safety, supplying oxygen-depleted gas to cargo tanks. However, poor maintenance or undisciplined operation can generate soot (fine carbon particulates) and discharge it overboard with wash water. Typical risk windows include start-up/shutdown, maintenance, and combustion inefficiencies (poor fuel atomisation, fouled burners, wrong air–fuel ratio). Visible pollution attracts immediate attention from authorities.
2) Boiler flue-gas IGS: lower risk, not zero risk
Using boiler flue gas can reduce soot formation versus standalone systems, but it still relies on effective cooling, scrubbing and filtration. Rapid boiler load changes and inadequate upkeep can cause particulate or droplet carryover, creating pollution concerns. 3) Open-loop scrubbers: wash water contamination under scrutiny
Open-loop scrubbers allow continued use of HSFO while meeting SOx limits, but failures (spray nozzles, blocked lines, defective pumps) and poor operational practice can discharge wash water contaminated with black carbon and particulates—often considered unacceptable in sensitive or tightly regulated ports.
Standards and gaps: scrubbers have numbers, IGS does not—yet enforcement still bites
For scrubbers, IMO MEPC.340(77) sets discharge criteria including minimum pH 6.5 at the discharge point (measured 4 metres from the outlet), limits on PAHs, and controls on turbidity and nitrates. For IGS soot/wash water discharges, there are no IMO-level numerical standards. Still, port and coastal States routinely treat IGS soot as a pollution incident under MARPOL and local laws, often applying strict or near-strict liability when pollution is visible.
What “good” looks like: prevention is procedural, not theoretical
West’s message is blunt: most incidents are preventable through disciplined operations, training and proactive maintenance:
- Follow manufacturer guidance with no deviations (IGS and scrubbers).
- Perform comprehensive pre-operation inspections; verify alarms and critical components.
- Train crew for normal operation, fault recognition, troubleshooting and emergency response.
- Consider cleaner tech (hybrid/closed-loop) when trading in strict regions.
- Keep robust records: operation logs, maintenance, sensor readings, visual observations.
- Enhance preventive maintenance beyond minimum requirements; adopt a vessel-specific checklist.
- Use real-time monitoring for early detection and corrective action before discharge.
Strategic conclusion (P&I / operational resilience)
The differentiator is not only technical performance—it is defensible readiness: documented procedures, consistent logs, traceable training and maintenance that exceeds the baseline. That is how you keep an incident from becoming a schedule-killer.
Open question: do you trade into ports where open-loop is restricted, and do you have a formal “stop/contingency” SOP onboard?
Source & reference: West of England (News, 17 Feb 2026), Anil Manipuzha – “Soot Pollution from Inert Gas Systems and Open-Loop Scrubbers”.
#IGS #Scrubbers #MARPOL #LossPrevention #PortStateControl #MarineInsurance #ShippingRisk
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