FAQs

Microplastics are tiny plastic particles, less than 5 millimetres in size, and often invisible to the human eye.  

Microplastics enter the environment either through the breakdown of larger plastic items, such as plastic bottles, or released directly from products and finishes, such as textiles, car tyres, and paint.

Microplastics can be categorized into the following formats:

• Fibre
• Fragment 
• Film 
• Foam 
• Bead (used in cosmetics) 
• Nurdle (plastic pellet feedstock used in manufacturing)

Two different definitions of primary and secondary microplastics exist, therefore it is important to check the definition being adopted in any data reference. 

One definition is based on how the microplastic enters the environment and the other is based on the manufacturing intention. 

Here is the definition based on how the microplastic enters the environment, as used by the International Union for Conservation of Nature (IUCN). 

Primary microplastics are plastics directly released into the environment in the form of small particulates. They can be a voluntary addition to products such as scrubbing agents in toiletries and cosmetics (e.g. shower gels). They can also originate from the abrasion of large plastic objects during manufacturing, use or maintenance such as the erosion of tires when driving or the abrasion of synthetic textiles during washing.

Secondary microplastics are microplastics originating from the degradation of larger plastic items into smaller plastic fragments once exposed to the marine environment. This happens through photodegradation and other weathering processes of mismanaged waste such as discarded plastic bags or from unintentional losses such as fishing nets. Given that, the origins of secondary microplastics are difficult to trace given their degradation; it is difficult to meaningfully assess how much of the figures of macroplastics have now converted to microplastics. It is for this reason that the report seeks to focus on quantification of primary microplastics, as it is achievable within current data sets.

Here is the definition based on manufacturing intention, as used by European Financial Reporting Advisory Group (EFRAG). 

Primary microplastics are intentionally produced and added to products (e.g. microbeads, glitter or stabilisers in cosmetics), resulting in a direct release into the environment during the use phase of the product or at their end-of-life. 

Secondary microplastics derive from the breakdown of larger pieces of plastics (e.g. plastic waste, such as packaging or fishing nets). These are fragments resulting from the breakdown of larger plastic debris like bottles, bags, synthetic tyres, and fishing nets.

Microplastics have been found in virtually every corner of the globe, from the Mariana Trench to the top of Everest, highlighting their pervasiveness in the environment. No ecosystem on Earth is untouched. The impact of microplastics on our planet has the potential to be so disruptive that it could destabilise processes that keep our planet habitable. 

“One of the most damaging and long-lived legacies of the plastic pollution crisis is microplastics, a growing threat to human and planetary health” 
United Nations Environment Programme  (UNEP)

Microplastics are associated with a broad spectrum of health risks. When ingested or inhaled, they can exert both mechanical and toxicological effects. 

The potential hazards of microplastics can be broadly categorized into three interrelated mechanisms: 

• Physical hazard from the particles themselves
• Chemical hazard from the plastic material and additives 
• Carrier (vector) hazard of pathogens and pollutants

Chemicals associated with microplastics include known mutagens, carcinogens, and endocrine disruptors. These are compounds that pose critical hazards to biological systems. 

Microplastics have been detected in human stools, blood, lungs, breast milk, placenta, intestinal lining, liver, kidneys, and the brain.

A 2024 study in the New England Journal of Medicine found that individuals with micro- and nanoplastics in arterial plaque had a 4.5-fold increased risk of heart attack, stroke, or death.

The ocean is Earth’s largest active climate regulator, producing around half of the planet’s oxygen and absorbing approximately one quarter of anthropogenic CO₂ emissions. 

Microplastic pollution is increasingly recognised as a threat to the plankton communities that underpin these critical ecosystem functions, adding further pressure to oceans already stressed by climate change, warming and acidification.

Phytoplankton produce oxygen through photosynthesis while converting atmospheric CO₂ into organic carbon, forming the foundation of the marine food web and the global carbon cycle. Studies indicate microplastics can reduce phytoplankton photosynthesis by up to 45%.

Zooplankton consume phytoplankton and play a central role in the biological carbon pump by transporting carbon from surface waters to the deep ocean through faecal pellets, vertical migration and, ultimately, their bodies after death. 

A reduction in phytoplankton decreases the amount of carbon available for transfer and long-term sequestration. Zooplankton also ingest microplastics, which can reduce feeding efficiency, growth, reproduction and survival, further diminishing the efficiency of carbon transport to the deep ocean. Experimental studies have reported reductions in zooplankton feeding efficiency of up to 40% following microplastic exposure.

Microfibres are very small fibres, less than 5 millimeters in size, that shed from textiles. 

Microfibre shedding occurs during manufacturing, use, washing, and disposal.

The term microfibre refers to microscopic textile fibres released from fabrics, irrespective of their material composition. Microfibres can be categorised into the following groups:

Synthetic microfibres (also referred to as microplastic fibres) are derived from petroleum-based polymers, including polyester, nylon (polyamide), polypropylene, acrylic and elastane. Cellulosic microfibres are derived from natural cellulose and include:

• Regenerated (man-made) cellulosic fibres, such as viscose, lyocell, modal, acetate and cupro.
• Natural plant fibres, such as cotton, flax and hemp.
• Natural animal fibres, such as wool and silk.

Therefore, all synthetic microfibres are microplastics, but not all microfibres are microplastics.

All microfibres, whether synthetic or cellulosic, are harmful to the environment. 

Synthetic microfibres (microplastic fibres) are of particular concern because the fibre itself is a persistent plastic pollutant. Synthetic polymers biodegrade extremely slowly, allowing them to persist and accumulate in the environment over very long timescales. In addition, synthetic fibres may release polymer additives and textile-associated chemicals and can act as carriers for contaminants present in the environment.

Regenerated cellulosic microfibres generally biodegrade more readily than synthetic fibres; however, their persistence varies considerably depending on fibre chemistry, textile processing, dyes, finishes and environmental conditions. Studies have shown that processed cellulosic fibres can remain in the environment for extended periods and may still be ingested by organisms, contribute to ecological impacts and transport textile-associated chemicals.

Consequently, while preventing synthetic microfibre (microplastic fibre) emissions remains a priority because of their very long-term persistence in the environment, reducing emissions of all textile-derived microfibres is important to minimise environmental pollution and protect the planet.