Robust analysis techniques are also driven by regulatory compliance
Today’s beauty consumers are more discerning than ever, with 80 per cent calling for stricter safety regulations in cosmetic products, according to recent research from Mintel. In response to growing demand for transparency, safety and efficacy, cosmetic manufacturers are under increasing pressure to validate the performance and safety of their products before they reach the market. Here, Dr. Prerna Sudera, industry specialist at Thermo Fisher Scientific, explores how in-house scanning electron microscopy (SEM) enables faster, safer development of cosmetic products while meeting these rising demands.
Modern cosmetics rely on a sophisticated blend of materials engineered for both function and aesthetics. These formulations incorporate everything from finely tuned emulsions that deliver smooth texture, to high-performance pigments for vivid, lasting colour and nanoscale particles and biomaterials designed to enhance absorption and skin compatibility.
Electron microscopy plays a vital role in revealing the microstructure and morphology of these complex formulations, offering invaluable insights into their performance, stability and interactions with the skin before they reach the market.
Looks aren’t everything
But it isn’t only about how products look and behave. As formations become increasingly complex — particularly with the increasing use of nanomaterials — the need for robust analysis techniques is also driven by regulatory compliance.
The foundational framework for cosmetics in the EU is Regulation (EC) No 1223/2009, which sets out comprehensive safety, labelling and product notification requirements. One of its key provisions is the requirement for nanomaterials to be clearly labelled on a product’s ingredient list, with ‘nano’ clearly stated, and for such products to be notified to the EC before being placed on the market.
Companies in the cosmetics sector must also consider their obligations under the broader REACH chemical regulation. Under REACH, cosmetics companies, as downstream users, must ensure their suppliers have properly registered the substances they use, especially if their annual manufacture volume exceeds one tonne. This includes ensuring access to up-to-date safety information such as safety data sheets, managing chemical safety and understanding any applicable restrictions or authorisations under REACH.
There are new regulations to consider too. In March 2024, the Official Journal of the European Union published Commission Regulation (EU) 2024/858 on the use of several nanomaterials, amending the EU Cosmetics Regulation. It restricts use of several common nanomaterials, such as colloidal gold and silver particles that are often marketed to boast skincare benefits, while also refining the definition of what constitutes a "nanomaterial".
EU regulations restrict other nanomaterials too, such as the use of nano-sized hydroxyapatite often found in dental products, which must have a limited concentration of ten per cent in toothpaste and 0.465 per cent in mouthwash. As of February 2025, cosmetic products containing such substances can no longer be placed on the EU market, and from November 2025 they won’t be made available altogether.
Meeting compliance in practice
External laboratories play a vital role in regulatory compliance. Verifying whether a substance qualifies as a nanomaterial — typically defined as having particles of 100 nanometres or smaller — requires precise, scientifically validated data. SEM is suited for this, enabling visualisation of particle size, shape, surface structure and aggregation state. It delivers both high-resolution imaging and quantitative evidence to support robust, transparent REACH documentation.
When selecting a suitable SEM, laboratories have several considerations to make. An ideal system for cosmetics should deliver both high-quality imaging and chemical analysis, while being easy to use and able to fit seamlessly into busy quality control and R&D environments.
The Axia ChemiSEM from Thermo Fisher Scientific lives up to these expectations, offering both high resolution imaging and elemental composition data in real time, from a single instrument. This dual imaging and analysis capability is particularly valuable when characterising complex cosmetic formulations, such as assessing the dispersion of pigments, verifying particle distribution or detecting unwanted contaminants that could impact safety and performance.
Many cosmetic formulations, such as serums and emulsions, rely on the interaction between water and active ingredients. In situ analysis is therefore an important technique when observing reactions as they occur. In their native state, these products can be difficult samples to analyse due to their hydrated states. But deep analysis can be made possible with an ESEM.
Elsewhere, hair morphology is another key indicator of cosmetic product performance, particularly when assessing treatments such as serums, dyes and heat-protection formulations. SEM enables detailed characterisation of the hair shaft’s surface structure before and after exposure to straightening and curling devices or chemical treatments. Changes such as cuticle lifting, breakage or smoothing can be visualised with high resolution, providing insight into a product’s protective or restorative efficacy. This analysis helps formulators refine ingredients to ensure they not only enhance aesthetic results but also preserve or improve hair health under real-world usage conditions.
The ability to support cooling and heating experiments both in high vacuum and low vacuum, making it able to analyse wet and hydrated samples, makes Thermo Fisher’s Quattro ESEM another favourable option for cosmetics. This capability also allows for precise observation of ingredient interactions and stability in the presence of water or humidity, helping refine product longevity and effectiveness for hair and beauty products.
Temperature experiments facilitated by the Quattro ESEM’s heating capabilities can also help assess how products behave in storage. Cooling experiments with the Peltier cooling stage help assess gel-based formulations or certain active ingredients respond to temperature drops, while heating stages allow for simulations of heat exposure. This is important for products such as sun cream that may be used in direct sunlight.
The cosmetic industry faces more regulations than ever before. Adhering to nanoparticle stringency, while producing products to meet a growing consumer appetite, makes the need for detailed, nanoscale analysis even more important. Cosmetic manufacturers may already reap the benefits of SEM, but would do well to consider options that bring multiple functions onto a single solution.
