I bought biodegradable soap—can I shower in the lake now?

Though most cottagers know not to shower in the lake, there is something that sounds very whimsical and refreshing about taking your bath to the water. And with the arrival of new ‘biodegradable’ or ‘eco-friendly’ soaps, you might be thinking it’s finally safe to bathe in the lake.

But before you don your towel and lug your shower caddy down to the shore for a sudsy soak in the great outdoors, here are some things you need to know:

Is biodegradable soap actually safe for the lake?

In a word, no. Gary Wheeler, a media spokesperson for the Ontario Ministry of the Environment and Climate Change, explains that biodegradable soap is not a safe alternative to regular soaps when it comes to maintaining healthy lake ecosystems. “Soaps and shampoos, even biodegradable ones, should not be used in lakes, and wash waters should not be directly drained into lakes either.”

Though labelled ‘biodegradable,’ at the end of the day, these alternative soaps are still adding foreign substances to the lake ecosystem. All soaps negatively affect lake chemistry.

What does biodegradable really mean?

Something about the word biodegradable implies the substance will simply dissolve into nothing. But this is not the case. Wheeler shares that ‘biodegradable’ means “the product will be broken down into naturally occurring substances like water and carbon dioxide.” He adds that “the amount of time or conditions needed for that to take place are not often considered for labelling purposes.” Plus, biodegradable soap requires soil—absent in lake water—to effectively break down.

What is advertised on the bottle is also not always accurate. “Soaps and shampoos may be labelled as “biodegradable” but can contain chemicals such as preservatives and surfactants, some of which may not be included in the ingredients list.”

How does it affect lake ecosystems?

While natural ingredients might be good for our health, the same can not be said for the microorganisms that call our lakes home. Ingredients often found in soaps, even biodegradable ones, such as phosphates, sodium lauryl sulphate and antibacterial agents, “can impact aquatic organisms, resulting in increased algae growth that may upset the freshwater ecosystem,” says Wheeler.

What can I do instead?

When it comes to alternatives, keep it simple. Adding nothing to the water is the safest course of action. “For eco-friendly lake bathing, simply scrubbing with lake water and a washcloth is recommended.”