Does Green Equal Clean?

Boat Soaps Put to The Ultimate Test

Courtesy Susan Shingledecker December 7, 2009

These days, most eco-minded boaters are looking to green their boat cleaning routine by utilizing environmentally friendly cleaning products—and manufacturers are responding in a big way. A quick scan of cleaners at a local boating supply store 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 Environmentally Smart. What do these terms mean and can the claims really be trusted? Most importantly, if a product is truly green will it still clean your vessel and rid it of harsh saltwater contaminants?

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We chose 20 popular boat soaps and put them to the ultimate test. To keep things simple and fair, only general boat soaps and all-purpose cleaners were tested and a few tried-and-true cleaning staples that do not make any environmental claims were also evaluated. Each cleaner was put through two types of tests, one in the lab to determine its toxicity and biodegradability, and another on a boat to determine its cleaning performance.

The Shopping List
There’s a wide variety of cleaning products on the market—everything from all-purpose cleaners for home or boat use, specialty cleaners that target 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 this case study, the soaps and all-purpose cleaners that were selected include:

  • 3M Marine Boat Soap
  • 4U Concentrated Cleaner
  • Boatlife Boat Cleaner
  • ConcrobiumXT Eco-Wash
  • Ecover Heavy Duty Boat Wash
  • Extreme Simple Green Motorsports
  • Meguiar’s Gel Wash
  • OrPine Boat Soap
  • Shurhold’s Yacht Brite Brite Wash
  • Simple Green All-Purpose Cleaner
  • Soft Scrub with Bleach Cleanser
  • Spray Nine Boat Soap
  • Spray Nine Green Marine Multi-Purpose Cleaner
  • Starbrite Sea Safe Boat wash
  • Thetford Marine Boat Wash
  • Thetford Marine Deck Cleaner
  • Trac’s Green Clean Boat Soap
  • West Marine Crystal Boat Soap
  • West Marine Pure Oceans All Surface Cleaner
  • West Marine Pure Oceans Boat Soap

In the Lab
To determine a product’s environmental impact it’s important to look beyond the label and evaluate its effect on aquatic life. While there are many different characteristics of a cleaner that can determine its impact on the environment, two elements are high-priority: 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 a team of graduate students performed larval toxicity assays with brine shrimp. The cleaners were diluted to determine the LC50, or the lethal concentration where only 50-percent of the organisms survive. Brine shrimp were then placed in the cleaner solutions diluted with various amounts of seawater and mortality was analyzed after 20-hours. To determine biodegradability, the lab technicians used the toxicity analysis and identified the LC80 for each cleaner, the lethal concentration with an 80-percent survival rate, and prepared dilutions of each cleaner at its LC80. Brine shrimp were again added to each cleaner’s diluted solution and the mortality was evaluated immediately, after two weeks and again after four weeks to determine how quickly the detergents biodegraded in seawater.

In the Field
To a boater, cleaning performance is essential. When purchasing a product you want to know if it will get the job done and leave your vessel with a shiny luster. To evaluate each cleaner’s performance three boats were lined up: 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 nearly two-years. Twenty one-foot segments were taped off along the hull of each boat and the cleaners were mixed and applied per the instructions on each bottle. The cleaning process started with a plain sponge. If that was not sufficient a medium-grade scrubbing pad was utilized, and if the boat was still not cleaned effectively a coarse bristled scrub brush was chosen. Rating each cleaning method helped determine the cleaning performance score.

Labels – Close Up
A quick scan of the labels on the tested cleaners reveals a wide range of green terms. Can the claims be trusted you ask? 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. The tests confirm this as 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 the test, 3M Marine Boat Soap, makes no environmental claims on its packaging, while the most toxic and one of the least biodegradable products tested includes terms such as: Ecological, Minimum Impact on Aquatic Life, Fast and Complete Biodegradability, and Phosphate Free on their label.

Five of the 20 products tested carry the EPA Design for the Environmental logo. According to the Environmental Protection Agency this logo indicates that every ingredient in the product has been screened 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, but it does represent a commitment on the part of the manufacturer to submit their product for review.

Thetford Marine Boat Wash carries the EPA DfE logo and performed excellent in both the toxicity and biodegradability tests. However, the other four DfE labeled products did not perform as well, especially when evaluating biodegradability.

When looking at environmental impact it is clear that more products performed well on toxicity than biodegradability. When determining the overall environmental impact it is important to note that 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. So, is it better to have a highly toxic product that biodegrades rapidly, or a less toxic product that does not biodegrade? Research has shown that the more toxic product that degrades rapidly would likely have less overall environmental impact. For this reason biodegradability was weighted higher than toxicity.

In conclusion both Thetford Marine Boat Wash and Meguiar’s Gel Wash were nearly 100-percent biodegraded in four weeks. ConcrobiumXT Eco-Wash was the hands down winner in biodegradability with nearly 100-percent degradation in only two weeks. Weighing all the factors: cleaning performance, toxicity, biodegradability and cost, Thetford Boat Wash came out on top. This cleaner is available in a concentrated, cost-effective formula, cleaned the boats relatively easily, and has low toxicity and high biodegradability. It is also readily available at major boating supply stores nationwide.

Green Your Cleaning Routine

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 important tips to remember.

Rinse your boat regularly with freshwater to prevent dirt and debris from accumulating. Follow the dilution recommendations on all cleaning products. It’s important to use the cleaning product as specified—whether applied directly to the hull, mixed in a bucket, or attached to a hose. Tests show that in most cases where the product had a range of recommended dilutions, that the weaker mixture with more water and less product was equally effective as the stonger mixture with a higher product concentration. Save yourself some money and stick with the weakest mixture recommended. Use an eco-friendly general boat soap for overall cleaning, then spot treat troublesome stains with a stronger product. Minimize run-off of any cleaning products by using a towel after harsh spot treatments.

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