Compliance Testing on Sea Vessels

Chelsea’s SeaSentry is a fully integrated turnkey solution to monitor exhaust gas wash water and meet IMO regulations, and Chelsea’s FastBallast is a portable instrument that provides rapid on-board testing of treated ballast water to ensure compliance with the IMO D-2 & USCG Discharge Standards around invasive species

Sea vessels undergo a variety of environmental compliance tests to conform to International Maritime Organization (IMO) regulations, the specialised agency of the United Nations responsible for regulating shipping.

The IMO was established following agreement at a UN conference held in Geneva in 1948 and came into existence ten years later, meeting for the first time in 1959. Headquartered in London, United Kingdom, IMO currently has 175 Member States and three Associate Members. Amongst other regulatory responsibilities, the IMO also has responsibility the prevention of marine and atmospheric pollution by ships and for the prevention of invasive species in ballast water.

Wash water compliance

On January 1st, 2020, a new IMO compliance limit on the sulphur content (SOx) in the fuel oil used onboard ships came into force. Known as IMO 2020, the rule limits the sulphur in the fuel oil used on board ships operating outside designated emission control areas to 0.50% m/m (mass by mass) – a significant reduction from the previous compliance limit of 3.5%.

Sulphur oxides are linked to asthma, pulmonary, cardiovascular and respiratory diseases, and reducing these harmful emissions improves the health of populations, especially those living near ports and coasts, and to help prevent premature deaths. A study on the human health impacts of SOx emissions from ships, submitted to IMO’s Marine Environment Protection Committee (MEPC) in 2016 by Finland, estimated that by not reducing the SOx limit for ships from 2020, the air pollution from ships would contribute to more than 570,000 additional premature deaths worldwide between 2020-2025.

The new IMO 2020 compliance limit was made compulsory following an amendment to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL). Prior to the entry into force of the new compliance limit, the majority of shipping used heavy fuel oil. Derived as a residue from crude oil distillation, heavy fuel oil has a much higher SOx content which, following combustion in the engine, ended up in ships’ emissions.

Since IMO 2020, the vast majority of ships now use very low sulphur fuel oil (VLSFO) to comply with the new limit, and other ships limit the air pollutants by installing exhaust gas cleaning systems, also known as scrubbers. Scrubbers are accepted by flag states as an alternative means to meet the SOx limit requirement – they are specifically designed to remove SOx from the ship’s engine and boiler exhaust gases. A ship fitted with a scrubber can use heavy fuel oil, since the SOx emissions are reduced to a level equivalent to the required fuel oil sulphur limit. By mid-July 2020, some 2,359 systems had formally been reported to IMO as an approved equivalent method flag States.

Scrubber emissions still need to be tested for compliance to ensure that they are doing the job they are intended to do, ie ensure that the SOx emissions are reduced to a level equivalent to the required fuel oil sulphur limit, which is where Chelsea Technologies’ Sea Sentry comes in, a cabinet suitable for retro fit and new installation into open, closed loop and hybrid scrubber systems.

Owners looking for monitoring systems should ensure that their system of choice performs the full regulatory analysis, as required by the IMO guidance, including PAH, pH, turbidity (to ISO 7027: 1999) and temperature. Installed in over 250 vessels and certified by DNV-GL and ClassNK, Chelsea’s Sea Sentry provides users with a full-range PAH measurement using a proven and highly accurate sensing technique. In addition, combined with its technical expertise, Chelsea is also working closely with leading global scrubber manufacturers to offer owners and operators a package solution designed to futureproof ship owners from impending regulation.

Ballast water compliance

ballast water complianceThe International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM Convention) was adopted by consensus at a Diplomatic Conference held at IMO Headquarters in London on 13 February 2004 and entered into force globally on 8 September 2017. The Convention requires all ships to implement a ballast water management plan – all ships are required to carry a ballast water record book and are required to carry out ballast water management procedures to a given standard. Parties to the Convention are given the option to take additional measures which are subject to criteria set out in the Convention and to IMO guidelines. The guidelines, some of which have been revised since their initial adoption, and a number of other relevant guidance documents can be accessed here, but in summary:

  • The D-1 standard requires ships to exchange their ballast water in open seas, away from coastal areas. Ideally, this means at least 200 nautical miles from land and in water at least 200 metres deep. By doing this, fewer organisms will survive and so ships will be less likely to introduce potentially harmful species when they release the ballast water.
  • The D-2 standard specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health. The D-2 standard specifies that ships can only discharge ballast water that meets the following criteria:
    • Less than 10 viable organisms per cubic metre which are greater than or equal to 50 microns in minimum dimension;
    • Less than 10 viable organisms per millilitre which are between 10 microns and 50 microns in minimum dimension;
    • Less than 1 colony-forming unit (cfu) per 100 mililitres of Toxicogenic Vibrio cholerae;
    • Less than 250 cfu per 100 millilitres of Escherichia coli; and
    • Less than 100 cfu per 100 milliliters of Intestinal Enterococci


SeaSentry – wash water compliance testing

  • Chelsea’s SeaSentry is a fully integrated turnkey solution to monitor exhaust gas wash water and meet IMO regulations
  • DNV-GL Type Approved, DNV-GL and Class NK in compliance with IMO MEPC 259(68)
  • Suitable for retro fit and new installation of open, closed loop and hybrid scrubber system
  • Full PAH Range – Full 0 – 4,500µg/L PAHphe measurement which provides full compatibility with all scrubber system flow rates
  • Two year calibration intervals on the PAH+ and Turbidity sensors allowing for uninterrupted monitoring
  • Easy to use onboard sensor check – the new Chelsea solid standards kit allows you to verify the sensor calibration onsite with easy to operate, robust and stable solid standards as part of the commissioning process, without the need for liquids or chemicals
  • Chelsea designed sensors and cabinet– as designers and manufacturers of both the sensors and complete system, Chelsea knows the science and the technology

FastBallast – ballast water compliance testing

  • fastballast invasive species testingChelsea’s FastBallast is a portable instrument that provides rapid on-board testing of treated ballast water to ensure compliance with the IMO D-2 & USCG Discharge Standards around invasive species
  • Quick & cost-effective – compliance level test in under 10 minutes decreasing need for shore-based laboratory involvement
  • Accurate – the most accurate indicative instrument on the market, removing the cost to go back out to sea, exchange ballast water and return to port
  • Simple – all-in-one portable instrument, including tablet, no consumables, designed to be operated by a single person
  • Future-centric innovative STAF technology also provides detection of living cells and cell density, beyond the current requirements of compliance testing

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