The International Chamber of Shipping (ICS), the big shipowners' lobby, has made a second plea to UN's International Maritime Organisation (IMO) to fix compliance problems in the UN's Ballast Water Management (BWM) Convention before it is too late.

Speaking at a Ballast Water Management Summit in Singapore, ICS vice chairman Esben Poulsson said IMO member states should make use proposals in an industry submission to the Marine Environment Protection Committee (MEPC), which next meets on October 13-17.

Mr Poulsson the IMO approval process for the expensive new treatment lacked robustness, particularly in the varying standards applied by each country's Port State Control inspectors, as well as the need to "grandfather" already fitted systems.

Yet governments have so far appeared reluctant to act collectively in a decisive manner, he said, adding that failing to resolve problems is causing much uncertainty.

"When the BWM Convention eventually enters into force, the shipping industry will be required to invest billions of dollars to ensure compliance.

"However, because of unanswered questions about the convention's detailed implementation, much of the industry continues to lack confidence that the new treatment equipment will actually work, or will comply with standards governments set," he said,

ICS is most concerned that port state sanctions could impact unfairly on shipowners who, in good faith, have fitted type-approved equipment only to be told they fall short of the required standard.