THE story feels familiar.

The International Maritime Organization will go back to the drawing board on a regulation that is already adopted, that all member states have agreed to; the moment is both an opportunity and a risk for environmental regulation.

The European Union’s proposal to MEPC 74, the Marine Environment Protection Committee meeting in mid-May, asks the IMO to consider developing rules for the discharge of scrubber washwater and calls for that to happen by 2021.

While the proposal does not suggest any actual measures or condemn open loop scrubbers, it does float the restriction of wash water discharges in certain areas as a potential one.

The proposal, or at least a suggestion of this kind, was in some ways expected. Even before the latest bans in Singapore, China and Fujairah had been rolled out, an anti-open loop scrubber sentiment had been growing as the abatement technology became more popular ahead of the 2020 sulphur cap.

Back in October, before the wave picked up momentum, one experienced IMO delegate had privately predicted that this dispute would be the next big immediate issue in the IMO.

Nor is the IMO a stranger to retroactive amendments to regulations. In 2017 it partially delayed the implementation of the ballast water management convention, leaving many shipowners relieved but frustrating others that had invested early, and some manufacturers also.

But this scrubber saga also feels different. The rules that will emerge will not be about time but rather, space; where will wash water discharges be allowed? The amendments are not about adding a cushion, but limiting operations.

The decisions must be convincing. Neither side of the debate for or against open loop scrubbers has been able to persuade that their point is undeniable truth.

There needs to be more studies and research into the effects of open loop scrubbers on the ocean; countries could conveniently seek — or resist — revising agreed measures based on questionable evidence that suits an agenda.

Introducing or not introducing restrictions on scrubbers without convincing evidence will not only leave the matter open to scrutiny in the coming years. It would set a dangerous precedent for the much more consequential policy of decarbonisation.

Countries, especially those that have introduced this proposal, should take it upon themselves to encourage and even launch such studies and encourage widespread participation. The IMO should encourage such initiatives to inform the debate.

Japan has already conducted one in its waters that found that open loop scrubbers do not present a threat to the ocean and its organisms. Expect more nations to follow with their own studies.

Unlike most floated environmental rules, which usually find members of the industry unified, this is a deeply divisive issue because money has already been spent.

The Clean Shipping Alliance, a group of major shipowners such as Star Bulk, Carnival and Torm, that have invested in scrubbers, was formed in direct response to a proposal last year that many thought was seeking a delay in the implementation of the sulphur cap — and hence a delay and perhaps even a decrease in their returns on investment.

The CSA is now committed to defending the reputation of open loop scrubbers, asserting that claims against the systems are scientifically unfounded.

Expect them to recruit as many member states and organisations as they can to help push their message over the next couple of years.

On the other hand, other industry leaders have been vocal in their opposition and it is quite clear a number of countries are keen to carry that torch.

The IMO and its member states must be cautious and diligent in manoeuvring around scrubber discharge regulations. This can be a good opportunity to jump ahead and preempt regional initiatives. Countries need to resist political temptations and make fact-based decisions.