The vast majority of paint currently used on the bottom of boats—whether small recreational yachts or giant cargo vessels and cruise ships—is “ablative”. This means that it is specifically designed to wear away and expose fresh biocide over time.  These ablative paints create negative environmental impacts that are not often fully considered.

Here are three things you might not know about ablative marine paints and the importance to consider an alternative approach.

  1. “The Cost of the Status Quo”

Did you know that a good ablative paint binder is designed to wear away at a rate of ~1 mil every 3 months? At first glance, this may seem like a testament to polymer engineering, but it begs the lifecycle analysis question: Where does all that material go?  And what impact does that have on marine life and water cycles globally?

  1. “How Bad is Bad?”

While the recent regulatory focus has been on copper (and may shift to zinc in the coming years), there has not been a lot of conversation about ablative paints themselves and the trail of chemical litter they leave in the ocean.  In the marine paint market, 80% of bottom paints are ablative copper, accounting for a total volume of over 8 million gallons.

Assuming an ablation rate of 3 mils per year, that equals a volume of 15,000 tons of plastic resins and biocide intentionally put into the ocean every year by the shipping industry.  These may take the form of microplastics, nanoplastics, or chemical fragments. Given that the goal of these materials is to kill any microbiological species they come into contact with, how do we assess the global damage done by this technology?

  1. “Well at Least it’s not Tin”

Every year, bottom paint sloughs off invisible piles of resin into the ocean. These calculations didn’t consider the copper content of the paints.  Although copper is a less lethal alternative to tin, which became known for destroying habitats throughout the world, it is still quite lethal itself.  There is talk of replacing copper with zinc, which would be another half-measure within the world of bottom paint.

Let’s assume an average copper content of 35% within a bottom paint and a total litter volume of 15,000 tons.  That means that this market segment is responsible for 5,000 tons of copper being dumped into our precious oceans.  While the environmental impact of ablative paint resin is unknown, the impact of copper is far more straightforward.  It is designed to kill marine life, and it does a great job.

Conclusion – SLIPS® Dolphin: “The Best Foul Release Ever Created”

AST had the benefit of winning an ARPA-E award in 2016 for the development of a non-biocidal bottom paint.  Since that time, we have been laser-focused on creating solutions for the shipping industry that allow them to make more sustainable decisions regarding bottom paint.

Recently, our SLIPS® Dolphin went head-to-head with Hempaguard X7 (a copper pyrithione containing foul release) on a commercial tanker, and at 18 months of use, the biofouling accumulation looks to be matching pace with Hempel’s technology.  Copper pyrithione is known to be a potent biocide and this data reinforces our belief that we have a competitive solution for customers looking to divest from copper and other biocides.