Proper Procedures

We put each cleaner through two types of tests, one in the lab to determine its toxicity and biodegradability and another on the boats, to determine its cleaning performance. 

In the Lab

To determine a product’s environmental impact we need to look beyond the label and evaluate its effect on aquatic life. This analysis is beyond the traditional scope of our usual Foundation Findings testing methods, so for this test we partnered with a leading university with laboratory facilities. The professor leading the effort has extensive experience with antifouling technologies and chemical ecology.

While there are many different characteristics of a cleaner that can determine its impact on the environment, we chose to focus on two elements: toxicity and biodegradability.  Toxicity relates to the negative effects of the substance on all types of organisms.  Biodegradability relates to the amount of time it takes a substance to break down into harmless components.

To determine the toxicity the university performed larval toxicity assays with brine shrimp.  They diluted the cleaners to determine the LC50 or the lethal concentration where 50 percent of the organisms survive.  To do this they placed brine shrimp in the cleaner solutions diluted with various amounts of seawater and analyzed mortality after 20 hours.  To determine biodegradability, they used the toxicity analysis and identified the LC80 for each cleaner, the lethal concentration with 80 percent survival, and prepared dilutions of each cleaner at its LC80.  Brine shrimp were added to each cleaner’s diluted solution and the mortality was evaluated immediately, after 2 weeks and again after 4 weeks to determine how quickly the detergents biodegraded in seawater. 

Analyzing the cleaners' environmental impacts in the lab.

Each cleaner was tested for toxicity and biodegradability

A graduate student examines brine shrimp in cleaner solution.