Methanol dual-fuel engines are no longer a concept. Ammonia projects are moving from trials into operational planning. LNG has already reshaped parts of the fleet. The shift is happening in real time, and regulation has had to keep pace.

That is where the IGF Code sits.

Across the industry, ship operators, technical managers and crew are hearing the term more frequently, often alongside discussions on alternative fuels, compliance and training. At Stream Marine Training in Glasgow, we see this first-hand. Delegates coming through our alternative fuels courses are already working on vessels or projects where the IGF Code is not theoretical, it is operational.

Understanding the regulation itself is the starting point. Training builds on that. Without clarity on what the IGF Code is, who it applies to, and how it fits into wider maritime law, the rest does not quite land.

The IGF Code in Context

The IGF Code stands for the International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels. It was adopted by the International Maritime Organization in 2015 and entered into force on 1 January 2017.

Crucially, it is not guidance. It is mandatory under the SOLAS Convention, which means ships that fall within its scope must comply.

The purpose is straightforward. As new fuels introduce different risks compared to conventional marine diesel, the industry needed a structured framework to ensure safety in design, construction and operation. The IGF Code provides that framework.

What makes it distinct is its approach. It is goal-based rather than fully prescriptive. Instead of detailing every technical solution, it sets safety objectives and functional requirements. Ship designers, builders and operators then demonstrate how those objectives are met.

The Code is split into two parts:

  • Part A contains mandatory provisions
  • Part B provides additional recommendations and guidance

That balance allows innovation in fuel systems whilst maintaining a consistent safety baseline across the global fleet.

Low-Flashpoint Fuels, Properly Defined

The term “low-flashpoint fuels” gets used loosely, but within the IGF Code it has a precise meaning.

A low-flashpoint fuel is any fuel with a flashpoint below 60°C.

Flashpoint is the temperature at which a fuel gives off enough vapour to ignite in air. Conventional marine fuels such as diesel typically have flashpoints above 60°C, which reduces the likelihood of vapour ignition under normal conditions.

Low-flashpoint fuels behave differently. They can produce flammable vapours at much lower temperatures, which introduces additional risks around ignition, explosion and vapour management.

The IGF Code covers fuels used for propulsion or onboard power, not cargo. This includes:

  • Liquefied natural gas (LNG), which the Code originally focused on
  • Methanol and ethanol
  • Hydrogen
  • Ammonia
  • Other gases and low-flashpoint fuels as they enter service

Each of these fuels carries different hazards. Rather than attempting to cover every scenario in detail, the IGF Code sets a safety structure that can be applied across fuel types.

For a closer look at how specific fuels behave onboard, including hazard profiles and handling considerations, our safety considerations guide for methanol, ammonia and hydrogen blog explores that in more detail.

Which Ships the IGF Code Applies To

The scope is clearly defined, but often misunderstood.

The IGF Code applies to:

  • Ships constructed on or after 1 January 2017
  • Ships using low-flashpoint fuels for propulsion or power
  • Cargo ships of 500 gross tonnage and above
  • All passenger ships, regardless of tonnage

It does not apply to ships carrying these fuels purely as cargo.

For existing vessels, the situation becomes more complex. If a ship is converted to operate on a low-flashpoint fuel, it will generally be required to meet IGF Code standards as part of that conversion. This is assessed on a case-by-case basis, typically involving the flag state and classification society.

Responsibility for compliance sits with the flag state, which issues certification confirming the vessel meets SOLAS and IGF Code requirements. However, compliance does not stop there.

Port State Control has the authority to verify that ships entering port meet applicable international regulations, including the IGF Code. That means compliance must be demonstrable at all times, not just at build or certification stage.

What the IGF Code Actually Regulates

The IGF Code is broad in scope because it addresses the entire fuel system lifecycle onboard a vessel.

Rather than acting as a technical manual, it defines safety requirements across key areas, including:

  • Fuel containment systems and storage arrangements
  • Fuel supply systems from tank to engine
  • Machinery installations and their location relative to hazardous areas
  • Electrical equipment in zones where flammable vapours may be present
  • Ventilation systems designed to prevent gas accumulation
  • Gas detection and monitoring systems
  • Fire safety and explosion prevention measures
  • Control, alarm and shutdown systems
  • Bunkering arrangements and procedures
  • Documentation and operational procedures

It also links directly to crew competency requirements under STCW. That connection is where many operators first encounter the practical implications of the Code.

If you are looking at how those training requirements translate into real roles onboard, our BIGF and AIGF training guide breaks down what different crew need before joining IGF Code vessels.

What This Means for Ship Operators

For operators, the IGF Code is not a box-ticking exercise. It influences decisions from concept design through to day-to-day operations.

On newbuild projects, compliance begins at the design stage. Naval architects and shipyards must demonstrate that the vessel meets IGF Code safety objectives. Classification societies play a key role here, reviewing designs and verifying that systems align with both the Code and class rules.

Before entering service, vessels must undergo certification confirming compliance with SOLAS and the IGF Code. That includes documentation, system verification and testing.

Once operational, the responsibility shifts to maintaining that standard. Operators need to ensure:

  • Fuel systems are maintained and inspected in line with requirements
  • Operational procedures are followed consistently
  • Crew are trained and competent for the specific fuel system onboard
  • Documentation is up to date and available for inspection

Port State Control inspections can include IGF Code checks. Inspectors may review documentation, crew certification and the condition of onboard systems. Non-compliance can lead to delays, detentions or further investigation.

There is also a commercial element. Planning for IGF Code compliance affects project timelines, costs and operational readiness. Retrofitting or converting vessels can be particularly complex, requiring careful coordination between designers, class and regulators.

At SMT, we often speak with operators at this stage. Training is one part of the wider compliance picture, but it needs to align with vessel design and operational timelines.

What It Means for Crew Onboard

From a crew perspective, the IGF Code changes how certain operations are carried out.

Working with low-flashpoint fuels introduces different procedures, different risks and different emergency responses compared to conventional fuel systems. That applies across deck and engine departments.

Training is therefore a core requirement. Under STCW, crew assigned specific duties on IGF Code ships must hold appropriate certification. For officers and engineers with responsibility for fuel systems, this typically means Advanced IGF training.

At Stream Marine Training, our Alternative Fuels Training Specialist, Captain Oli Olsen, brings operational experience from vessels using these fuel types. That practical background is critical. The regulation sets the framework, but real-world application is what crews need to understand.

Our AIGF course focuses on preparing officers and engineers to operate safely within that framework, building directly on IGF Code principles.

We also deliver Port State Control IGF Awareness training for those involved in inspection and verification roles.

Where the IGF Code Sits in Maritime Law

The IGF Code does not exist in isolation. It is embedded within a wider regulatory framework.

At the top level, it is mandatory under SOLAS, which governs safety at sea. That gives it legal force for ships flying the flag of IMO member states.

It also links to:

  • STCW, which defines training and certification requirements for seafarers
  • MARPOL, which addresses environmental protection and emissions
  • Classification society rules, which build on IGF Code requirements for design and construction

Flag states are responsible for implementing these requirements within their registries. Classification societies support compliance through design approval and surveys. Port State Control provides an additional layer of verification when ships call at port.

Understanding how these pieces fit together helps operators and crew navigate compliance more effectively. The IGF Code is one part of the system, but it connects directly to how ships are designed, operated and crewed.

A Regulation That Will Continue to Evolve

When the IGF Code entered into force in 2017, LNG was the primary focus, but the landscape has already shifted.

Methanol-fuelled vessels are entering service, ammonia is being tested at scale and hydrogen projects are progressing. Each of these fuels introduces new technical and safety considerations.

The Code is designed to evolve alongside that change with amendments and updates regularly as the industry gains operational experience.

For operators and crew, that means staying informed is not optional. It is part of maintaining compliance and ensuring safe operations.

At SMT, we continue to adapt our training to reflect current regulations and real-world developments. Our Glasgow-based team works closely with industry professionals to ensure what we deliver remains relevant to the vessels entering service now.

Bringing It Together

The IGF Code is no longer something on the horizon. It is already shaping how ships are designed, built and operated.

For operators, it defines how alternative fuel projects move from concept to compliant vessel. For crew, it sets the standard for safe operation onboard.

Training sits within that framework, but it starts with understanding the regulation itself.

If you are working with IGF Code vessels, planning a newbuild or preparing crew for deployment, we can help. Stream Marine Training delivers AIGF, BIGF and IGF awareness training from our Glasgow facility.

For more information, contact bookings@streammarinetraining.com or call +44 (0)141 212 8777.

FAQs: ENG1 Medical Certificate

What does ENG1 stand for?

ENG1 is the UK MCA medical fitness certificate code. It confirms you meet medical standards for work as a seafarer on UK-flagged vessels or for UK-issued certificates of competency.

Do I need an ENG1 before starting STCW training?

Yes, most UK training providers (including Stream Marine Training) require a valid ENG1 before your STCW course starts. Some allow conditional booking whilst you arrange your medical.

How long does an ENG1 medical certificate last?

Typically 2 years. Some certificates are issued for shorter periods (1 year) if medical conditions need regular monitoring. Check the expiry date on your certificate.

Can my regular GP issue an ENG1 certificate?

No. ENG1 medicals must be conducted by MCA-approved doctors. Regular GPs cannot issue ENG1 certificates. Find approved doctors on the MCA website.

How much does an ENG1 medical cost?

Typically £80-£120 depending on clinic location. Prices vary between approved medical examiners. This is paid directly to the medical clinic, not to training providers.

What happens if I fail the ENG1 medical?

If medical concerns are identified, the doctor may issue a conditional certificate, request further specialist assessment, or decline certification. You can reapply once medical concerns are addressed.

Can I get an ENG1 medical with diabetes?

Possibly, if well-controlled. Many seafarers with managed diabetes hold ENG1 certificates. The examining doctor assesses control levels, medication, and monitoring. This is assessed individually.

Do I need an ENG1 for offshore oil and gas work?

Yes, if you’re working on UK-flagged vessels or need UK certification. Offshore OPITO training also requires valid medical fitness certification. Check with your employer.

How long does the ENG1 examination take?

Usually 30-45 minutes including all tests and medical discussion. Results are often available the same day or within 48 hours.

Can I book my STCW training before getting my ENG1?

At SMT, you can provisionally book whilst arranging your ENG1, but the valid certificate must be in place before your course start date. Contact us if you have questions: bookings@streammarinetraining.com