Is Soap Safe for Bathing in Lakes?

I can bathe in the lake if I use biodegradable soap, right? This is a myth. Just don’t do it. No matter what the label says.

"Biodegradable", "safe for rivers, lakes, ocean", "all-natural", "non-toxic", "eco-friendly". These labels sound good but are not without significant impacts to aquatic life. In fact, the greenwashing by companies trying to sell products by making promises and claims that sound good is downright greed. Simply said, they put profits over people and planet.

 

What does biodegradable mean?

Biodegradable means "capable of being broken down (decomposed) rapidly by the action of living organisms, producing water, carbon dioxide, and biomass." Because something can biodegrade doesn’t mean it will.  [See 1] And just because something is biodegradable doesn't mean it is safe.

 

Fact: Even if soap (liquid or bar) is biodegradable, it is not safe to use directly in the river, lake or ocean. Never, ever. All soap, whether biodegradable or not, affects the chemistry of rivers and lakes and has a negative impact on fish and other organisms.

Soap (including handmade and commercially made) falls into the category of surfactants.  Synthetic detergents are also surfactants. They are called surfactants because they  break the surface tension of water. To humans it might not mean much, but to the organisms that live in the water it’s a big deal. Lower surface tension also reduces the oxygen in the water. Decreased oxygen can cause stress and ultimately kill aquatic life.

Another culprit is phosphorus because it feeds algae. Algae blooms can turn lakes into thick smelly green soup that is undesirable for swimming and other recreational water activities. Too much algae clouds water and blocks sunlight from reaching aquatic plants. [See 2]

 

So, how do I stay clean while in the woods?

Here are a few suggestions taken from blog post: Personal Hygiene on the Trail

• Most State campgrounds have shower facilities that you can use for a fee. The water is usually warm; be sure to bring some quarters, your favorite soap and a microfibre quick-dry towel with you.
• Take a trail shower using handmade, cold processed soap, such as Mountain Girl Soap, a jug of water and a washcloth. Pay special attention to your face, hands, underarms, privates and feet.  Oh, and be sure you are 200 feet away from a water source.
• Take a sponge bath with UNSCENTED (unless you want to be a skeeter magnet) moist towelettes or wipes. Again be sure to focus on those important areas. And pack the wipes out with you. A better option is to wet a reusable microfiber towel with a few drops of liquid soap and water. Afterward, hang the towel from your pack to dry and rinse out at the next water spigot/drain you come to. 
• Jump in a lake or stream. Just skip the soap all together so you don't harm the aquatic life. The cold water is a bit of a shock but will rid you of some sweat and dirt. 

If soap is not safe for aquatic life and use in the lake, is soapy water safe for use on plants and the soil (grey water system)?

Read my article on Is Your Soap Safe for Greywater Systems?

 

What else should I know?

Even if you don’t use soap to wash in the lake or river, think again before getting into water with your chemical laden body, including lotion, deodorant, sunscreen, insect repellent, and the like. These can contaminate water sources just the same or worse. For this reason, Hawaii has banned chemical sunscreen. [See 3]

 

Want some more resources? 

Bubbles belong in the bathtub
https://grist.org/living/ask-umbra-is-it-ok-to-lather-up-in-the-lake-with-biodegradable-soap/

Biodegradable Soap in the Backcountry: The Campsuds Myth
https://sectionhiker.com/biodegradable-soap-in-the-backcountry-the-campsuds-myth/

Handmade Soap Guide - Nearly Everything You Need To Know

 

1. https://www.themarinediaries.com/tmd-blog/a-lesson-in-biodegradability
2. https://kingcounty.gov/services/environment/water-and-land/lakes/facts/boats-docks.aspx
3. https://www.staradvertiser.com/2018/07/03/breaking-news/hawaii-becomes-1st-state-to-ban-sale-of-sunscreens-with-coral-harming-chemicals/

 

Happy Camping,