From forever chemicals showing up in drinking water to microplastics being found in the human brain, manmade materials persisting in the environment is a growing concern. This has driven a demand for readily biodegradable products across industries, particularly in the cleaning and home care sector.
But is readily biodegradable always best? When formulating products, should you look for chemicals that break down as quickly as possible?
Answer: it depends.
Here’s why:
Types of Biodegradability
Before we get into the specifics of whether a product should biodegrade as quickly as possible, let’s talk first about the different types of biodegradability.
Materials are generally categorized into three groups of biodegradability: readily biodegradable, inherently biodegradable, and persistent.
Readily biodegradable substances undergo significant degradation into simpler compounds within a relatively short period, usually 10 days or less (https://locusingredients.com/learning-center/3-categories-biodegradability/).
Inherently biodegradable substances take longer to break down, usually 4 to 8 weeks, but they will ultimately decompose to simpler substances.
Persistent substances have little to no likelihood of breaking down, and as a result can potentially accumulate in the environment.
Ultimately, it's best for all materials to break down and return to the earth. How long that should take, however, depends on the material.
How Long Should Biodegradation Take?
Highly active chemicals should not spend any more time in the environment than necessary. Surfactants or common soap, for example, are very active and break down the walls of bacteria. This makes them effective disinfectants, but potentially harmful if they remain active after their use. These types of chemicals should be readily biodegradable so that they impact the environment as little as possible.
If a chemical is safe and nontoxic, however, it does not need to biodegrade immediately. Take cellulose for example, which is the structural component of wood and plants. Cellulose is not readily biodegradable, has essentially no toxicity, and can biodegrade over many years without any negative impact on humans, animals and the environment.
Similarly Itaconix TSI 422, an ingredient partially derived from plants, is a safe, low-toxicity material that does not harm the environment. Due to its plant-based nature, TSI sequesters biogenic carbon, releasing that carbon little by little back into the atmosphere as it degrades. The longer TSI persists in the environment, the longer it holds carbon.
So, it is not only fine for TSI to degrade slowly—it is preferable.
Ask the Right Questions
Whether you’re a product manager selecting ingredients for a formulation, or a consumer selecting a product off the shelf, the best question to ask is: is this ingredient safe and will this persist in the environment?
Ultimately, all materials should break down and return safely to nature. When and how they get to that final destination, however, should always depend on the safety of the material itself.