Scrubbers are bad — here’s how you can help protect our oceans from their toxic washwater
In an attempt to reduce air pollution from shipping, the International Maritime Organization (IMO) passed legal limits on the amount of sulphur content in ship fuel. But rather than switch to more expensive but cleaner-burning fuels, the industry used a loophole big enough to drive a, well, ship through.
While the acceptable amount of sulphur fell from 3.5 per cent to 0.50 per cent, IMO rules also allowed vessels to meet these new emission standards by installing scrubber systems.
Officially known as Exhaust Gas Cleaning Systems, scrubbers don’t actually clean anything. Rather, they “scrub” sulphur oxides from engine and boiler exhaust mixing them with seawater to capture the contaminants, converting would-be air pollution into water pollution.
This scrubber exception allows ships to continue burning cheap — but very dirty — heavy fuel oil (HFO) despite its high sulphur content. And in Canada, that results in these ships dumping the equivalent of nearly 80,000 Olympic-swimming pools of toxic and highly acidic scrubber washwater into our oceans each year.
READ MORE: No, I don’t want no scrubbers
WWF-Canada has long advocated for a scrubber ban in Canada, and globally. We welcome Transport Canada’s public consultation on vessels using scrubber systems. Open until January 19, this is an opportunity for Canadians to stand up for people and wildlife by telling the federal government to ban scrubbers once and for all.

How to have your say
You can make your voice and concerns heard by sending an email to [email protected] and include “Scrubber Systems in Canada” in the subject line.
Not sure what to say? See below for some suggested points on why Canada should ban ships from dumping toxic scrubber waste in Canadian waters, stop approving scrubbers for use on Canadian ships, and take action at the IMO to ban scrubbers globally.
- Scrubbers are bad for our air: Scrubbers allow ships to continue burning the dirtiest marine fuels and, according to Environment and Climate Change Canada, as a result, ships with scrubbers emit 104 per cent more black carbon, or soot, than ships without scrubbers. This harmful particulate matter is linked to premature deaths, cardiopulmonary disease, lung cancer and chronic respiratory ailments. It also undermines the intent of Canada’s emission control areas and, in the Arctic, accelerates sea-ice melt.
- Scrubbers are bad for our ocean: Most ships with scrubbers use open-loop systems, which continuously suck in seawater, which mixes with the “scrubbed” exhaust and discharges it in a hot, acidic and highly contaminated state containing dissolved metals and carcinogens. Closed-loop scrubbers produce smaller volumes of more concentrated waste released into the sea periodically. In 2022 alone, scrubber-equipped ships dumped a staggering 199 billion litres of scrubber washwater into Canada’s oceans, including in protected areas.
- Scrubbers are bad for wildlife: Scrubber washwater is toxic to marine life, with harmful effects observed at concentrations as low as 1 part per million (ppm). At 10 ppm, it causes significant malformations in the juveniles of some species. Scrubber washwater is also highly acidic, contributing to worsening ocean acidification and impacting the ability of shellfish like oysters and sea urchins to grow and maintain skeletons and shells.
- Scrubbers are bad for the climate: Scrubbers perpetuate the use of HFO, slowing the transition to cleaner alternative fuels, and scrubber-equipped ships emit 4 per cent more carbon dioxide.
- Scrubbers are bad for the rule of law: The United Nations Convention on the Law of the Sea (UNCLOS) requires Canada to not “transfer, directly or indirectly, damage or hazards from one area to another or transform one type of pollution into another.” Yet, Canada (and the IMO) currently allows scrubbers that convert air pollution from burning HFO into liquid waste, which is then dumped into the ocean.
Scrubbers are no solution — they worsen pollution, accelerate climate change, and harm the health of people and wildlife all while violating international obligations.
Please speak up for a scrubber ban while you have the chance!