Microplastics in cosmetics: What do you need to know?

What are microplastics and why do they cause problems?

Microplastics are very small plastic particles that cause a very big problem. We commonly encounter microplastics in cosmetics. They’re of concern, because they have a combination of the following properties:

• Microplastics are smaller than 5 mm, which means they can be eaten by both animals and humans
• They’re indestructible, which means they remain in the environment for a long time
• They’re difficult to remove from the environment, which leads to them ending up in our drinking water.
• Microplastics degrade into smaller and smaller pieces, making the above 3 points even worse

Microplastics are mainly a problem if they end up in the environment, because they accumulate there. This will eventually cause damage to both nature and people.

Where do microplastics actually come from?

Microplastics can be made in two ways:

1. They can be added to products for their unique properties, such as to scrubs and facial products
2. Microplastics can be created by the breakdown or damage of products containing plastic, such as textiles or packaging material

Many different industries use microplastics, such as the automotive, packaging and agricultural industries. For the cosmetics industry, the problem consists of 3 parts:

• What is the impact of cosmetics on microplastics in the environment?
• How do you know if a product contains microplastics?
• What can be used to replace microplastics in cosmetics?

What is the impact of cosmetics on microplastics in the environment?

Of course, cosmetics aren’t the only source of microplastics in the environment. But if we compare cosmetics with the other sectors, they’re in the top 3 for both the use of microplastics and the pollution caused by microplastics.

Cosmetics even make up (no pun intended) for 10% (!) of all microplastics in the environment. An important industry, where a lot of impact can be made.

How do microplastics from cosmetics get into the environment?

Microplastics made in the cosmetics industry can end up in our ecosystems in two ways. namely:

• Via wastewater (also known as down-the-drain)
• Via normal ‘solid’ waste

Here, of course, there’s a big difference between the types of cosmetics. It will come as no surprise rinse-off cosmetics, such as shampoo and scrubs, are the largest source of microplastics in wastewater.

But leave-on cosmetics (such as nail polish and body lotions) are also a major source of microplastics in the environment.

In the case of leave-on cosmetics, for example, this is because the consumer uses face cream in the morning, but washes their face later in the day.

Or make-up removed at the end of the day using a washable cleaner or a cotton pad with cleansing lotion. Or nail polish that flakes over time. All these can lead to microplastics in our ecosystems.

Filtering microplastics from waste: how do you do that?

Fortunately, wastewater and solid waste containing microplastics do not directly end up in the environment. In both cases, a lot of effort is being put into separating and purifying the waste and even into recycling the microplastics.

Purifying the wastewater is very efficient and currently takes place in three steps:

• In step one, ~80% microplastic is already filtered out of the water
• In the second step, 97.5%
• And with the third step, 99.2%

The filters are actually very good at removing microplastics from the water! The only problem is what happens to the waste getting filtered out of the water afterwards.

The residue containing microplastics is often used as compost for agriculture, where microplastics end up directly in the environment via the soil (100% release). Or it’s buried underground, where the microplastics eventually enter the environment via the air (10% release).

Despite the almost complete purification from water, these secondary waste pathways ensure microplastics still have a collective release of 50% into the environment via wastewater.

Usually, solid waste is burned to generate energy. Few microplastics end up in the environment during this process (less than 0.5%). A larger, and quite remarkable share of solid waste is through the recycling of cosmetics packaging. Recycling packaging produces microplastics that can end up in the environment via wastewater.

The combined total release of microplastics from solid waste comes down to about 6%. Compared to the 50% release via the waste water from rinse-off cosmetics, solid waste from leave-on cosmetics has a lower impact on microplastic release into the environment.

How do you know if there are microplastics in a cosmetic product?

So far, we’ve talked about the major impact of the cosmetics industry on the release of microplastics into the environment. To be able to identify these microplastics in cosmetic products, we dive deeper into the definition of the name microplastic.

Because what is the exact definition of a ‘microplastic’ and how do you know whether a product contains them?

Part of the discussion immediately starts with the definition of ‘microplastic’; various definitions for microplastics have been drawn up by, among others, the European Chemicals Agency (ECHA) and Beat the Microbead.

Microplastic: ECHA’s definition

The definition used by the European Chemicals Agency ECHA is as follows:

‘microplastic’ means a material consisting of solid polymer-containing particles, to which additives or other substances may have been added, and where ≥ 1% w/w of particles have all particle dimensions between 100 nm ≤ x ≤ 5mm for fibers, a length of 3nm ≤ x ≤ 15mm and length to diameter ratio of >3.

There are exceptions to this; polymers with the following criteria aren’t included in the definition of microplastics:

• Polymers that are (bio)degradable as proposed by ECHA in Appendix X of their proposal
• Polymers occurring in nature that have not been chemically modified (other than by hydrolysis)
• Polymers with a solubility > 2 g/L, according to the criteria in Appendix Y of their proposal
• Polymers without any carbon C in their chemical structure

Exceptions 1 and 2 seem logical, because these types of substances aren’t a part of the problem. They can be removed from the environment, or are already part of the environment anyway. These weren’t introduced by humans. Point 3, according to ECHA, water-soluble polymers don’t fall under the definition because they aren’t ‘particles’.

Point 4 is a remarkable point; this was added because ECHA currently doesn’t have the right tools to determine the persistence of these types of polymers. The inability to determine persistence is, according to ECHA, a good enough argument not to consider these substances as microplastics.

This is odd, because the Cosmetics Regulation itself takes the position only substances demonstrated to be safe are allowed for use in products; not that substances may be approved ‘because there is no information that they are dangerous’.

Microplastic: the definition of Beat the Microbead

The organization Beat the Microbead (BtM) uses different criteria for the definition of microplastics. We briefly summarize the definition below, but the extensive criteria can be found in BtM’s microplastic report.

• All particle dimensions ≤ 5mm
• All fibers ≤ 15mm
• No exceptions

It’s immediately clear the criteria of Beat the Microbead are stricter, since they don’t use a lower size threshold; nanoplastics (even smaller than microplastics) are also included in this definition.

In addition, there is no exception for water-soluble polymers, since these polymers are solid at the time of use.

Water-soluble polymers can also be biopersistent and toxic, so ‘water solubility’ isn’t considered an adequate criterion by BtM. Also, in this definition, there’s exception for polymers without carbon C in their molecular structure.

Testing biodegradability

BtM indicates the lack of tools should not be an excuse to make exceptions. In addition to the stricter definition of a microplastic, BtM advocates for doing more in the field of biodegradability, both in the definition and in testing methods:

For testing biodegradability, BtM argues a better series of tests and criteria is needed in order to call a substance biodegradable or not.

This is mainly because the degradation rate (half-life) isn’t tested. In other words: ‘is the substance broken down fast enough not to be a problem for the environment?’

This is a great question. If a plastic is only broken down very slowly, the pieces of microplastic will also remain intact for a long time and cause more problems.

BtM also argues the definition of biodegradability for mixtures should be stricter. According to the ECHA, a mixture of biodegradable and non-biodegradable plastic can currently be labelled as ‘biodegradable’.

BtM advocates this shouldn’t be allowed, and that substances should be tested specifically and separately. According to BtM, a mix of biodegradable and non-biodegradable substances should not be called a biodegradable product.

This is how you check whether a product contains microplastics in 3 steps

Due to these different definitions, there are also several ways to check whether cosmetics contain microplastics.

ECHA has compiled a list of more than 500 ingredient names (page 277, Appendix D.1). Based on this, you can follow this step-by-step plan:

Step 1: Compare all ingredients in the product with the ECHA list. These are active ingredients, but also additives and other substances added to the product.

Step 2: If one of the product ingredients is on the list, check whether it meets the ECHA microplastic definition:

• physical state
• particle size
• molecular structure
• exceptions and deviations from the definition such as water solubility and biodegradability

Step 3: If the product ingredient meets all criteria, it is a microplastic. It doesn’t meet all the criteria? Then, according to ECHA, it isn’t a microplastic.

Beat the Microbead uses the same list as ECHA but without exceptions. Based on this, they’ve created four groups to classify products:

• Red: these are products with microplastics
• Orange: these are products with potential microplastics, for which insufficient data is available as of yet
• Green: these are products without microplastics or potential microplastics
• Zero: this means that all of a brand’s products are plastic-free

What can be used to replace microplastics in cosmetics?

Now that we know what a microplastic is and how to identify it, we can work towards replacing microplastics in cosmetics.

An example of the successful replacement of microplastics is the phasing out of so-called microbeads. These are plastic granules used in rinse-off exfoliating skin products or scrubs.

These microbeads were previously widely used, because they work well and they’re cheap. But because these were typically used in rinse-off products, and almost immediately wash away, many extra microplastics were suddenly measured in our wastewater.

Recently (between 2017-2020), it was decided to phase out microbeads and replace them with sugar-based scrub granules, for example.

As a result, the impact of cosmetics on the total microplastic release in the environment has dropped from 11% to 10% in a short time. This is a significant step forward, which has resulted in ~400 tons fewer microbeads ending up in our ecosystems per year .

Phasing out microplastics in the cosmetics industry

Phasing out all microplastics is going to be one of the biggest challenges the cosmetics industry will face this decade. We all agree that it is necessary.

The current question remains: how to start? The initiative shouldn’t lie with legislators, but ultimately starts with consumers. They want to use safe products, both safe for themselves, and for the environment.

A clear trend for the cosmetics industry, in which we can help make the world a bit more beautiful, plastic by plastic, bead by bead.