Environmentalists are urging a moratorium on exhaust gas scrubbers after a report showed Carnival Corp had committed dozens of violations in using the IMO 2020 devices.
The June 2018 document cited many offences, from dumping plastic garbage into the ocean to running faulty scrubbers in environmentally sensitive areas.
A court-appointed monitor (CAM) team issued the report as part of a five-year probation against Carnival in December 2016 for illegally dumping oil into the ocean for eight years.
Carnival also paid a $40m fine for the wrongdoing, which included lying to US authorities about the unlawful discharge from Princess Cruises ships.
The CAM team in 2016 identified 34 incidents in which they allege ships' faulty scrubbers illegally burned 3.5%-sulphur heavy fuel oil (HFO) or emitted scrubber effluent within emission control areas.
In response the the findings, 10 environmental groups today sent a letter to IMO Secretary-General Kitack Lim, calling for the moratorium on the units, also called exhaust gas cleaning systems (EGCS).
The International Maritime Orgainzation's Marine Environment Protection Committee meets this week in London for its 74th session.
"The multiple equipment malfunctions and software failures would, in isolation, cast significant doubt on the ability of EGCS technology to meet the required equivalency standard," the three-page letter states.
"However, the findings of the CAM highlight the most significant problem with relying on this technology to meet regulatory standards: human error."
The report cited several instances of equipment failure, one causing a P&O Cruises ship to burn unfiltered HFO for 16 hours inside the Icelandic Environmental Protection Zone.
In another, a Princess Cruises ship allegedly burned HFO without an operating scrubber inside the North American Emissions Control Area, off the US coast of Alaska, for seven hours.
“As Carnival Corp’s criminal debacle has shown, EGCS are not the answer to delivering air pollution reductions for the shipping sector," Stand.earth senior shipping campaigner Kendra Ulrich said.
"We are calling on the IMO to take the lead on avoiding the inevitable failures and resulting environmental and health impacts of scrubbers by putting in place a moratorium while the IMO reviews the technology’s marine and air pollution impacts."
Ulrich said the moratorium would be "relatively easy" to implement while burning cleaner, low-sulphur fuel.
A US federal judge will decide next month whether or not she will temporarily ban the Arnold Donald-led cruise major from docking at US ports, based on the report's findings.
'Ridiculous and outlandish assertions'
Carnival refuted the findings, saying it has reduced its carbon footprint by 25% as part of its "top priority" to protect the environment.
"We have a strong successful track record with our advanced air quality systems around the world, supported by qualified independent third party studies," spokesman Roger Frizzell told TradeWinds.
"These are ridiculous and outlandish assertions, especially since this break-through technology is proven to be environmentally friendly and were developed in close coordination with the appropriate regulatory bodies such as the EPA and IMO, and independently verified by class societies and other scientific studies."
Discussion on scrubbers' efficacy to lower HFO's sulphur content to 0.5% per IMO 2020 rules is always welcome, said Clean Shipping Alliance 2020, a group of pro-scrubber shipowners, including Carnival.
"However, the comments made by Stand.earth and others are based on nothing more than sensationalist hyperbole intended for the media, without any underlying facts or evidence whatsoever," the organisation said.
