Castrol has launched a new stern tube oil range, Castrol BioStat ST. The stern tube oil range is for use in stern tubes, CPP systems and stabilizers. It has been developed and tested to comply with the U.S. Environmental Protection Agency Vessel Incidental Discharges Act (VIDA) 20182, with the lubricant being biodegradable, minimally toxic and not bio accumulative, as currently defined by the 2013 US VGP criteria
The lubricant is based on selected synthetic esters and an optimized performance...
https://www.marinelog.com/news/new-castrol-biostat-st-meets-epa-vda-requirement/