Since laundry scent boosters are intended to dissolve in the washing machine, you might not have thought much about their environmental impact.
However, these products can contain harmful ingredients that end up in waterways. They are also often made from unsustainable materials.
Here’s everything you need to know about the environmental impact of scent boosters.
1. What Are Scent Boosters Made Of?
Also known as laundry beads, scent boosters are often made from polyethylene glycol, which is soluble in water.
Scent boosters will also contain fragrances and sometimes dyes.
The exact ingredients will vary per brand and product. You may also come across the following ingredients:
- Synthetic fragrances
- Titanium Dioxide
- Essential oils
Some brands are also vague about their ingredients.
The label might say “scent,” “dispersant,” or “coloring,” but not specify what these actually are. This makes it hard to determine the environmental impact.
A dispersant is used in products as a stabilizer and to help the product disperse.
Common dispersants include EDTA-NA, sodium dodecyl sulfonate (SDS), polyvinyl pyrrolidone (PVP), sodium hexametaphosphate (SHP), sodium dodecyl benzene sulfonate (SDBS).
Essential oils, coumarin, geraniol, limonene, and linalool are plant-based, while glycerol can be sourced from plants or animal fat.
2. Are Scent Boosters Eco-Friendly?
Some scent boosters are more eco-friendly than others, for example, those containing non-toxic, biodegradable ingredients.
However, manufacturing them will still have an environmental impact due to sourcing materials and processing them.
For example, producing glycerin is energy-intensive. Given that most electricity use worldwide is still predominantly reliant on fossil fuels, high energy use is unsustainable.
Many scent boosters also come in plastic packaging. So, even if the scent boosters are made from renewable materials, the packaging may not be.
Although PEG and PVA are biodegradable, they are not renewable as they are made from petroleum.
Petroleum is typically sourced via drilling, which is detrimental to the environment.
This process can release carbon dioxide and methane, which has an even greater warming capacity.
3. Are Scent Boosters Toxic?
Some scent boosters may be toxic – it depends on the ingredients.
As mentioned earlier, some brands are vague about what ingredients are in their product, so there is no way to tell if the fragrances they use are synthetic or not.
Many fragranced goods emit volatile organic compounds (VOCs), which are a cause of air pollution.
Although PEG is generally believed to have low toxicity in living organisms, it is not completely harmless.
It has been linked to nephrotoxicity. Nephrotoxicity refers to the detrimental effect some substances have on the kidneys.
Research also suggested it caused damage to the heart and central nervous system in animals.
When tadpoles were exposed to PEG, it was found to accumulate.
The accumulation of PEG correlated with an increase in H2O2 (hydrogen peroxide) and ROS (reactive oxygen species). ROS can damage DNA.
However, other studies found that PEG had little to no toxic effects on aquatic ecotoxicity tests.
Although PEG used in scent boosters ends up in wastewater treatment systems, some of these particles may end up entering the environment.
There also appears to be a limit to the biodegradability of this compound, as larger PEG molecules are slow and difficult to degrade.
There are also other ingredients to consider. Research shows that coumarin is toxic and acts as a carcinogen.
When it comes to fragrance products, it is not advised to be exposed to more than 0.04 mg per kilogram of body weight per day.
However, the use of this compound in food and in cosmetic products does not seem to pose a health risk to humans.
Limonene itself is not regarded as toxic, but it interacts with other compounds in the air.
Limonene and ozone were noted to trigger inflammatory cytokine production.
The use of glycerine in cosmetics is regarded as safe.
Some kinds of essential oils are toxic to non-target organisms, including marine life, but it is not clear if there would be enough of these compounds in scent boosters to cause harm.
Benzene is considered a carcinogen and has been linked with smog.
Acetaldehyde is acutely toxic to marine life and can cause irritation when humans or animals are exposed to it.
Acetaldehyde also reacts with other chemicals in the environment to create smog.
Although scent boosters were not included in the study referenced above, they, too, could release air pollutants in the wash.
4. Are Scent Boosters Biodegradable?
Some scent boosters may be biodegradable, but not all.
It should also be noted that biodegradation can only take place in certain environments.
So while scent boosters could contain materials that can be biodegraded by bacteria in soil, they might not be able to break down in the water.
As mentioned earlier, although PEG is biodegradable, larger molecules are difficult to biodegrade.
However, since scent boosters are quite small, it is not clear if the PEG would be difficult to break down.
Although PVA is also biodegradable, studies found that approximately 77% of it is still intact following wastewater treatment.
These are also the other ingredients to consider.
While the likes of essential oils and glycerol are biodegradable, many synthetic fragrances, dyes, and other ingredients are not.
For example, EDTA and PVP are not biodegradable, but as mentioned earlier, many brands do not specify exactly what dispersants they use in their products, so it is difficult to determine the environmental impact.
5. Are Scent Boosters Sustainable?
Generally, scent boosters are not sustainable.
PEG and PVA are derived from petroleum, which is non-renewable.
As mentioned earlier, manufacturing glycerine is energy-intensive.
Although many of the common ingredients are plant-based, scent boosters often come in plastic packaging, which is unsustainable as plastic is non-renewable and has limited recyclability.
Plus, some of these plant-based ingredients can still be toxic.