What Is Marpol and How Does It Affect You

The MARPOL Convention was adopted on 2 November 1973 at the International Maritime Organisation (IMO), which in turn is a division of the UN. The International Convention for the Prevention of Pollution from Ships to give it its full name, lays out regulations aimed at preventing and minimizing pollution from ships - both accidental and from routine operations.

Marpol applies to large ships and smaller pleasure craft too


In 1978 a more comprehensive protocol was introduced and merged with the existing one after a number of tanker accidents in 1976-1977. Further protocols were added and amendments made over the years with the addition of Annex VI which entered into force on 19 May 2005. Currently Marpol includes six technical annexes that each look at specific areas of concern. These annexes are:

Annex I  Regulations for the Prevention of Pollution by Oil (entered into force 2 October 1983)
Annex II  Regulations for the Control of  Pollution by Noxious Liquid Substances in Bulk  (entered into force 2 October 1983)
Annex III Prevention of Pollution by Harmful Substances Carried by Sea in Packaged Form (entered into force 1 July 1992)
Annex IV Prevention of Pollution by Sewage from Ships  (entered into force 27 September 2003)
Annex V Prevention of Pollution by Garbage from Ships (entered into force 31 December 1988) 
Annex VI Prevention of  Air Pollution from Ships (entered into force 19 May 2005)


Important to note is that Marpol applies to all vessels both commercial and leisure with there being some more stringent regulations for larger vessels, particularly over 400 gross tonnes, soon to be reduced to 100 gross tonnes. Annex V in particularly is applicable to all vessels. It covers garbage prohibiting the discharge of all garbage and discharge into the sea, with some notable exceptions including cleaning products so long as they are considered not harmful to the marine environment. 

Mapro cleaning products on board


It has been known for the authorities in marinas to come aboard and check which cleaning products are on board and whether they are suitable and Marpol compliant. There has also been testing of the water around boats to see what chemicals from products are in the ocean and boats have been fined when traces of unsuitable cleaning agents have been found in the water. 

How then can you ensure that you do not fall foul of the Marpol regulations and are using compliant products. It starts by understanding the regulations themselves which are not particularly well known within the yachting community despite their relevance and importance. This is in part because in the past they have not been particularly well enforced. However, this is changing. It’s also worth noting that within the UK, they have informed the UK’s Marine Guidance Note: Pleasure Vessels - UK Regulations applicable to all UK registered vessels and vessels in UK waters. 

To review, the Marpol Regulations specific clause around cleaning products states:

1.7.4 While cleaning agents and additives contained in hold washwater and deck and external surface washwater are considered "operational wastes" and thus "garbage" under MARPOL Annex V, these cleaning agents and additives may be discharged into the sea so long as they are not harmful to the marine environment.

1.7.5  A cleaning agent or additive is considered not harmful to the marine environment if it:

  1. is not a "harmful substance" in accordance with the criteria in MARPOL Annex III; and
  2. does not contain any components which are known to be carcinogenic, mutagenic or reprotoxic (CMR).

1.7.6  The ship's record should contain evidence provided by the producer of the cleaning agent or additive that the product meets the criteria for not being harmful to the marine environment. To provide an assurance of compliance, a dated and signed statement to this effect from the product supplier would be adequate for the purposes of a ship's record. This might form part of a Safety Data Sheet or be a stand-alone document, but this should be left to the discretion of the producer concerned. 

The wording above can be seen as unclear and  too vague and we agree. It needs to, and likely will be tightened up over the coming years. However, essentially to be in compliance with Marpol Annex V 1.7.5 only cleaning products that do not contain ingredients considered to be harmful to aquatic life can be used on board. 

That seems to be easier said than done though. A recent study we recently commissioned of leading yacht wash products found that out of 11 yacht wash products, eight contained ingredients that are harmful to aquatic life, two had undetailed or incomplete SDS and only Ecoworks ecoYacht Wash could be categorically said not contain any ingredients considered harmful to aquatic life. Ecoworks ecoYacht Wash was the only product that complied with Marpol.

This then leaves you with the question of which products are compliant. An Ecocert, Ecolabel or equivalent is a great sign that the product is making efforts to meet sustainable credentials. However it has to be said that we have found certified products that contain ingredients harmful to marine life. 

The best way currently to ensure that you are using products that are safe for the environment and compliant with Marpol is to check the Safety Data Sheet (SDS) which can often be found online on the brands website and must be provided by law by the company on request. All our Safety Data Sheets for example, can be found under each product on our website. It is good practice to have the SDS of the products you’re using on board readily available in case of inspection. This will help authorities quickly ascertain whether the boat is abiding Marpol regulations. 

To quickly ascertain in the SDS whether the product is safe, look out for hazard warning codes that can be found in section 3 under the composition and information on ingredients. Particular codes to look out for are H400, H401, H410, H411, H412, H413 and H420. These warning codes all tell you that the product contains an ingredient known to be harmful to aquatic life to some degree. To understand more about Safety Data Sheets you can read our on demystifying Safety Data Sheets blog which breaks down what safety data sheets are and how to read them. 

Maprol applies to ships of all sizes

In the past Marpol has been poorly enforced and the degree to which it is enforced varies massively between different countries' waters. As a result it has been easy to not worry about or even ignore the regulations as a small superyacht or pleasure vessel. Technically speaking currently, any violation of the MARPOL 73/78 Convention within the jurisdiction of any country signed up to the convention is punishable either under the law of that country or under the law of the flag State. Even at sea though, if the relevant certificates are failed to be shown or the ship is suspected of not adhering to Marpol, the inspecting authority can detain the ship until it is satisfied that the ship can proceed to sea without presenting unreasonable threat of harm to the marine environment.

As the public and governments become more aware of the environment and start to react, governments and authorities will start to enforce Marpol more effectively and it's already happening. Furthermore regulations are also likely to be tightened up and improved upon with new regulations already due to be added to Marpol in 2024. 

As the authorities start to clamp down on and implement Marpol regulations, it is becoming increasingly risky for yacht owners and operators to ignore Marpol regulations, particularly for charter yachts. Some of the simpler rules are very easy to implement, store garbage on board, do not flush grey and black water into the ocean and use marine safe cleaning products. You can read the entire Marpol regulations here

Hopefully this article has helped a little on Annex V but if requested we’re happy to do a more detailed look into a simplified breakdown of the Marpol regulations.