Hundreds or even housands of litres of hazardous chemicals may be discharged into the Baltic Sea
More information
Within the framework of international legislation, carcinogens and other chemicals that have been proven to be harmful to aquatic organisms can be discharged into the Baltic Sea along with tank washwater. Companies that use chemicals should be required to take responsibility for the emissions of their entire transport chain.
Carcinogens and other chemicals are likely to end up in the sea at least on a weekly basis.
According to international maritime regulations, tankers are allowed to discharge chemicals into the sea with tank washwater under certain conditions: the ship must be at least 12 nautical miles (about 22 km) from the nearest shore and the sea must be at least 25 metres deep.
“In the shallow Gulf of Finland, this means that tank washing is in practice carried out in a relatively small area. Large volumes of many different chemicals end up in this area, and their combined effects on marine organisms are not properly understood,” says Eeva Tähtikarhu, Project Manager for the John Nurminen Foundation’s maritime traffic projects.
There are several major chemical ports in the Gulf of Finland, and the most important ones on the Finnish side are Kilpilahti in Porvoo and HaminaKotka.
Chemical emissions always pose a risk to marine environments
In the Chemical Tanker Project, the John Nurminen Foundation and Traficom have analysed both the harmful chemicals that tankers are discharging into the Baltic Sea and their effects on the marine environment. They have also reduced chemical emissions in collaboration with chemical industry companies.
The project has identified the three most significant high-risk chemicals that may be discharged into the sea at Finnish ports: tall oil, styrene and benzene. Tall oil emissions have now been completely prevented, but styrene and benzene are still being discharged into the sea.
Styrene and benzene are carcinogenic and mutagenic substances that have been proven to be harmful to aquatic organisms.
“The project has calculated that a single ship can discharge hundreds or even thousands of litres of chemicals into the sea at a time along with its tank washwater. Styrene is still being discharged into the sea every few weeks from ships unloading at Finnish ports,” says Tähtikarhu.
The solid vegetable oil that ended up on Hanko’s beaches made these chemical discharges visible, but most emissions are difficult to detect, as many chemicals are invisible in seawater.
“Although chemical emissions get diluted by seawater, scientific models have shown that even legal discharges of the most harmful chemicals will always pose a risk to marine environments.”
Some discharges are also illegal. Monitoring in Sweden detected discharges of tanker washwater in nature conservation areas. Tankers have also been observed discharging excessive amounts of chemicals into the sea in contravention of international regulations, and tank washing has been carried out too close to the shore.
Tall oil operators set an example for the entire sector
Companies that use chemicals should be required to take responsibility for the emissions of their entire transport chain. Companies that use hazardous chemicals should ensure that the ships they use do not discharge any cargo residues into the sea. In the best case scenario, if tanks are washed at the port where the cargo is unloaded, any residues will be collected for reuse.
“The tall oil industry is an example of how an entire sector has taken joint responsibility for its emissions throughout the transport chain. All companies transporting tall oil in Finland are committed to ensuring that the ships transporting their cargos wash their tanks ashore. This guarantees that no tall oil residues end up in the sea,” says Tähtikarhu.
Tank washing at port would also be technically feasible for styrene and benzene, but would entail additional costs for the companies using the chemicals, and may also require ships to spend longer in port.
“We’ve been advocating for stricter international regulations on tank washwater. However, international regulations are slow to change and enforcing them at sea is extremely challenging. Which is why the most effective way to reduce chemical emissions is for companies to commit to recovering their tank washwater,” says Annamari Arrakoski-Engardt, CEO of the John Nurminen Foundation.
Project reduces discharges of harmful substances into the Baltic Sea from tank washing on chemical tankers.
Read more
