Is soy wax biodegradable? Can it be composted?

  • Date: May 13, 2022

From lip balm to candles, soy wax is becoming a popular ingredient in day-to-day items. However, candles and remnants of soy wax-related beauty products are not commonly recycled, and this leads to issues when it comes to disposal. Are they destined for landfill? Or is soy wax biodegradable and can it be put in the compost bin? Mostly, yes! Although be sure it doesn’t contain any harsh chemicals – or you could end up with a contaminated pile…

Firstly, where does soy wax come from?

If we know the origin of a product, this is the first step in determining if it is biodegradable (and, potentially, compostable) or not.

Soy wax comes from soybeans, a species of legume. After they have been harvested the process begins. The beans are washed, the hulls are removed (dehulling) and they are rolled into flakes. Oil is then extracted from the flakes and hydrogenated. And voila – we have soy wax!

So, is soy wax biodegradable?

If an item is said to be biodegradable, it can be broken down naturally by bacteria and other micro-organisms. By this process natural products can, essentially, return to nature.  As we have seen, soy wax is a natural material – this makes it fully biodegradable. Synthetic alternatives, such as paraffin wax, will just breakdown into tiny pieces over time. This can cause harm to the environment rather than the nourishment a biodegradable item can bring.  

It should be noted that although soy wax can break down within months, the conditions need to be suitable. Many people assume that an item will biodegrade in landfill in the quoted timeframe for breakdown. Unfortunately, this is (generally) not the case. In landfill items tend to be packed closely together, there is simply no space for all the new waste being constantly added. The lack of airflow and moisture can slow down the process significantly. This is the reason we always advise reusing items and diverting them from landfill for as long as you possibly can – even biodegradable ones like soy wax products. 

Is soy wax compostable?

Composting can help us reduce how much of our household waste we put in the trash and, ultimately, send to landfill. At the same time, it also provides some nutritious fertilizer to use in the garden. Everyone wins! However, it is a common misconception that if an item is biodegradable, it can be composted. The words ‘biodegradable’ and ‘compostable’ do not mean the same thing – there are subtle differences. For instance, if an item is biodegradable but contains toxic chemicals it may not be suitable for composting – the chemicals could contaminate the pile. Thankfully, pure soy wax fits the bill when it comes to composting.

Composting materials fall into two categories. ‘Green’ materials refer to items that are rich in nitrogen such as fresh grass or even urine. ‘Browns’, on the other hand, are rich in carbon and include items such as cardboard and cotton.  Soy wax falls into the carbon-rich ’browns’ category. It is important to ensure you have suitable proportions of both ‘browns’ and ‘greens’ in the mix. Too much carbon-rich material can lead to your compost pile being too dry and provides inviting conditions for an ant invasion. Too many ‘greens’ can have the opposite effect – a slimy (and rather smelly), wet mess! As with most composting endeavours, some experimentation may be required. But sticking to a more straightforward 1:1 ratio should do the job. Just monitor it and make changes as you go. 

As far as composting goes, soy wax (and other natural waxes such as beeswax) are quite simple. It should only take a matter of weeks – or months. It is a great place to start for composting beginners. If you are new to the composting arena, we have answered some of the commonly asked newbie questions here.

Some considerations when composting soy wax….

As mentioned, if a biodegradable item contains harsh chemicals it may be unsuitable for your compost pile. Just because a product is made from soy wax does not mean it is 100% natural. Often, in the case of candles, soy wax may be blended with paraffin wax. Also, chemicals may be added to give them a more distinctive smell or to add some color. You should consider this when adding soy wax to your compost pile. We advise you to have a look at the ingredients list before deciding if it is suitable or not. When it comes to composting, a more cautious approach is often better than risking contamination and potentially harming your garden with the end-product.

As mentioned previously, composting is a relatively quick process. However, you can speed it up even more by breaking the wax into smaller pieces.  This gives the bacteria a larger surface area to work on. In addition to this, the smaller pieces can be easily distributed in the pile, spreading their carbon-richness throughout.   

The bottom line

We can all do our bit to help divert items from landfill and composting can be a great alternative to throwing items in the trash.  If you have a soy wax product that you can’t reuse or repurpose in some way, it can add a useful carbon-rich ‘brown’ ingredient to your pile. Just be sure to check the ingredients list for any nasty chemicals or synthetic materials that could cause your garden more harm than good!