We examine so-called green boat soaps to see if the soaps live up to their environmental claims and, if truly green, if they still clean well.
Green Cleaners — Overview
These days many boaters are looking to green their boat cleaning routine by searching for environmentally friendly cleaning products—and manufacturers are responding. A quick scan of cleaners on a boating store shelf reveals a wide range of products with various green terms including: Biodegradable, Non Toxic, Phosphate-Free, Recycled, EPA Design for Environment, Eco-Friendly Formula, Environmentally Safe, Environmentally Friendly, and perhaps our favorite, Environmentally Smart. What do these terms mean? Can you believe the claims? And most importantly, if a product is truly “green” will it still clean your boat? In Foundation Findings #47 the BoatU.S. Foundation set out to answer these questions.
We put 20 boat soaps to the test. With so many products on the market, we stuck to general boat soaps and all-purpose cleaners to keep things simple. Many of the soaps tested make green claims on their labels. We also, as a control, included a few tried-and-true cleaning staples that do not make any environmental claims. We sent one set of cleaners off to a university laboratory for toxicological analysis and we kept a second set for our hands-on cleaning effectiveness tests.
The Shopping List
There is a wide variety of cleaning products on the market – everything from all-purpose cleaners for home or boat use, specialty cleaners targeted to specific types of dirt such as mildew and black streaks and products that target specific surfaces or parts of the boat such as teak cleaners and bilge cleaners. For the purpose of this test, we focused on general boat soaps and all-purpose boat cleaners. We also included a few tried and true general cleaning products that we commonly see in the hands of boaters.
For general boat soaps we tested:
- 3M Marine Boat Soap
- 4U Concentrated Cleaner
- Boatlife Boat Cleaner
- Ecover Heavy Duty Boat Wash
- Meguiar's Gel Wash
- OrPine Boat Soap
- Shurhold's Yacht Brite Brite Wash
- Spray Nine Boat Soap
- Starbrite Sea Safe Boat wash
- Thetford Marine Boat Wash
- Trac Green Clean Boat Soap
- West Marine Pure Oceans Boat Soap
- West Marine PureOceans Crystal Boat Soap Eco Series
General all purpose cleaners tested:
- ConcrobiumXT Eco-Wash
- Simple Green All-Purpose Cleaner
- Soft Scrub with Bleach Cleanser
Spray cleaners we tested:
- Extreme Simple Green Motorpsorts
- Spray Nine Green Marine Mulit-Purpose Cleaner
- Thetford Marine Deck Cleaner
- West Marine Pure Oceans All Surface Cleaner
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.
To a boater, cleaning performance is very important. When buying a product you want to know if it will get the job done and leave you with a shiny clean boat. To evaluate each cleaner’s performance we lined up 3 boats: a well cared for boat with a wax finish and minimal dirt, a boat with some mildew and an oxidized finish, and a boat that had been stored under trees, uncovered and untouched for two years. We marked off 20 one-foot segments along the hull of each boat, mixed and applied the cleaners per the instructions on each bottle.
We started cleaning first with a plain sponge. If that was not sufficient we moved on to a medium grade scrubbing pad, and if the boat was still not cleaned sufficiently we moved on to a course bristled scrub brush. Rating each cleaning method helped us determine the cleaning performance score.
Labels — Close Up
A quick scan of the labels on our tested cleaners reveals a wide range of green terms. Can you believe the claims? In a nutshell, no. Unfortunately for consumers, there is no regulation for the use of claims such as "non toxic" and "biodegradable" that are found on many labels. Our tests confirm this as we discovered a few "green" labeled products appeared to be among the most harmful products tested, and some conventional products were far less toxic than suspected, yet made no environmental claims on the packaging.
The least toxic product in our test 3M® Boat Soap makes no environmental claims on its packaging, while the most toxic and one of the least biodegradable products in our test includes terms such as: Ecological, Minimum impact on aquatic life, fast and complete biodegradability, and phosphate free on their label.
EPA Design for the Enviornment Logo
Five of the 20 products tested carry the The EPA Design for the Environmental logo. According to the EPA this logo indicates the EPA has screened every ingredient in the product for potential human health and environmental effects and has determined that the product contains only those ingredients that pose the least concern among chemicals in their class. The logo does not mean that the cleaner as a whole has been tested. It however represents a commitment on the part of the manufacturer to submit their product for review.
How did these products measure up? Our staff pick Thetford Marine Boat Wash carries the EPA DfE logo and performed excellent in both our toxicity and biodegradability tests. But the other four DfE labeled products did not perform as well, especially when evaluating biodegradability.
Results — Can Green Clean?
When looking at environmental impact it is clear to see that more products performed well on toxicity than biodegradability. When determining the overall environmental impact the two factors are not weighted equally. The time it takes a product to degrade is more important than its initial toxicity. The longer the products lasts in the water, the more time it has to impact aquatic organisms. We asked our university partners, "Is it better to have a highly toxic product that biodegrades rapidly, or a less toxic product that does not biodegrade?" They told us that the more toxic product that degrades rapidly would likely have less overall environmental impact. For this reason we weighted biodegradability higher than toxicity in our evaluation.
Both Thetford Marine Boat Wash and Meguiar’s Gel wash were nearly 100% biodegraded in 4 weeks. ConcrobiumXT Ecowash Gel was the hands down winner in biodegradability with nearly 100% degradation in only 2 weeks. Weighing all the factors: cleaning performance, toxicity, biodegradability and cost, our Staff Pick is Thetford Boat Wash. This cleaner comes in a concentrated, cost-effective formula, cleaned the boats relatively easily, with low toxicity and high biodegradability. It is also readily available at major boating supply stores nationwide.
Spray vs. Wash
In our test we included both wash-style cleaners that were mixed with water in a bucket as well as spray bottle cleaners. Across the board the spray cleaners or cleaners applied directly to the hull were more toxic than wash-style cleaners. However, spray cleaners can be wiped with a cloth and may be less likely to runoff into the water.
We also tested one cleaning cloth that is perhaps the greenest cleaner as it does not have any run off. We found the Streak Free cloth at a boat show and decided to try it out. We followed the instructions on the package to "Wet it – Wring it – Wipe it" and were pleased with the result. This sturdy cloth can be rinsed, washed and reused.
Green Your Cleaning Routing
Most of the cleaners performed similarly well in the cleaning performance tests, with a few stand outs and a few disappointments. We did not find much correlation between environmental impact and cleaning performance. Meaning that generally the "greenness" of a cleaner did not impact its ability to clean.
Regardless of your choice of cleaner, how you use it can determine your environmental impact as much, if not more than, the toxicity and degradability of the product itself. Factors such as how much you dilute a product, how much you use, and where you clean your boat all contribute to the amount of product that ends up in the environment. Here are some tips to remember:
- Rinse your boat regularly with fresh water to prevent dirt and debris from accumulating.
- Follow the dilution recommendations on all cleaning products. It is important to use the cleaning product as specified – whether applied directly to the hull, mixed in a bucket, or attached to a hose. We found that in most cases where the product had a range of recommended dilutions, that the stronger mixture worked equally well as the weaker mixture. So save yourself some money and stick with the weakest recommended solution that works.
- Use an environmentally friendly general boat soap for an overall cleaning, then spot treat those troublesome stains with a stronger product. We found that regardless of "green" claims, the five cleaners that were directly applied with a spray or a paste were hundreds, to thousands of times more toxic when used as directed than the 15 boat soaps that are mixed with water in a bucket.
- Minimize runoff of any cleaning products by using a towel after harsh spot treatments.
Biodegradability - relates to the amount of time it takes a substance to break down into harmless components.
Toxicity - relates to the negative effects of the substance on all types of organisms.
Phosphate-Free – Means that a compound is free of phosphates. Phosphates have long been used in many cleaning products and fertilizers. They can also be found in sewage, urban and agricultural runoff. Phosphates promote plant and algae growth that can be harmful as it depletes oxygen in the water needed by other organisms.
Post Consumer Recycled - Post-consumer material is an end product that has completed its life cycle as a consumer item and would otherwise have been disposed of as a solid waste. Post-consumer materials include recyclables collected in commercial and residential recycling programs, such as office paper, cardboard, aluminum cans, plastics and metals.
Recyclable – the product is suitable for recycling though common methods. This product does not necessarily contain any recycled content.
Recycled – composed of materials that have been recovered. Recovered materials are wastes that have been diverted from conventional disposal such as landfills for another use. Recovered materials include both pre-consumer and post-consumer wastes. Pre-consumer materials are generated by manufacturers and processors, and may consist of scrap, trimmings and other by-products that were never used in the consumer market.