Completely preventing lubricants leaking from a ship into the marine environment is nearly impossible, despite the introduction of new vessel and equipment designs. Even the best run ship with the latest technologies and seals will always face the risk of potentially polluting the water with its lubes. In 2010 Dr Dagmar Schmidt Etkin, president of Environmental Research Consulting, showed just how big the problem is. Her study estimated that 4.6 to 28.6 million litres of lubricating oil from stern tubes is discharged into port waters each year. The impact that this quantity of oil was having on the marine environment immediately drew the attention of ship operators, legislators and the oil industry alike.
The USA has so far been the only jurisdiction to require ship operators to use Environmentally Acceptable Lubricants (EALs). In 2008, the US Environmental Protection Agency (EPA) issued Vessel General Permit (VGP) legislation focusing mainly on discharges from vessels but also recommending the use of biodegradable lubricants. In 2013 the EPA issued a second VGP that made the use of EALs mandatory. Whether or not other jurisdictions introduce legislation mandating the use of EALs remains to be seen, but the focus on the benefits of these products continues to be strong.
EALs, sometimes erroneously known as ‘bio-lubricants’, must be used in all situations where a lubricant come into direct contact with the ocean. Areas of vessels affected include controllable pitch propellers, stern tubes, rudder and thruster bearings, stabilisers, Azimuth thrusters, propulsion pod lubrication and wire rope and mechanical equipment that are subject to immersion. They must be biodegradable, minimally-toxic, and not bio-accumulative.