Nanoparticles are insoluble or bio-persistent materials ranging in size from 1 to 100 nm. In cosmetics, the nanoparticles permitted in the annexes of the European Regulation are carbon black as a colourant, and titanium dioxide, zinc oxide, the tris-biphenyltriazine, the methylene bis-benzotriazolyltetramethylbutylphenol (MBBT) as ultraviolet filters. These elements are currently the subject of controversy due to their potential toxicity to health and the environment. Focus.
Why doesn't Typology use nanoparticles?
Summary
Published on February 14, 2024, by Maylis, Chemical Engineer — 5 min of reading
Nanomaterials, nanoparticles... let's clarify.
The Cosmetic Regulation n°1223/2009 defines a nanomaterial as a insoluble or bio-persistent material, intentionally manufactured and characterised by one or more external dimensions or an internal structure, on a scale of 1 to 100 nm. This definition is specific to cosmetic products. A nanomaterial is considered as such if it is composed of at least 50% nanoparticles (elements with a nanometric size, between 1 and 100 nanometres).
Present in various types of treatments, nanoparticles appear as a non-soluble or bio-persistent element. Beyond sun care products, nanoparticles have paved the way for other uses in cosmetics. They are notably found in foundations, lipsticks, eyeshadows, and hair care products. The European Cosmetic Regulation n°1223/2009 has introduced a framework for nanomaterials, obliging manufacturers to be transparent.
Since the 11th of July 2013, when a nanomaterial is used in a cosmetic product, the packaging of this product includes in the list of ingredients the notation [nano] following the name of the ingredient.
Why introduce nanoparticles into cosmetic skincare products?
Firstly, at the nanometric scale, the efficacy of a substance can be enhanced, which allows for the improvement of a cosmetic product's properties. This can lead to a boost in optical properties, tactile properties, or even texture characteristics.
For instance, the optical properties of nanoparticles provide makeup products such as eyeshadows with a "pearlescent" or "light" effect. The zinc oxide and silicon dioxide found in some "smoothing special" foundations retain the enzymes that cause dryness and roughness of the skin.
Nanoparticle pigments (such as carbon black), found in certain mascaras, prevent reversible darkening: whether the eyelashes are exposed to natural or artificial light, the appearance remains the same depending on the wavelength and intensity of the surrounding light.
In sun care products, nanometric titanium dioxide is used because, at this size, this ingredient has two advantages: it acts as a more effective UV filter against the harmful rays of the sun and it avoids the "white streaks" effect.
Why are nanoparticles criticised?
Nanoparticles in cosmetics are currently a subject of controversy due to several arguments:
Their impact on health:
Existing studies on the subject contradict each other: some attest to the harmlessness of nanoparticles on health when applied topically, while others demonstrate the opposite. Titanium dioxide (TiO2) is particularly under scrutiny. This UV filter is used in sun creams due to its excellent light-reflecting capacity. A 2015 study shows that skin damaged by sunburn or atopic skin allows TiO2 nanoparticles to penetrate more easily, the skin barrier protecting the body from the environment being weakened. The nanoparticles can then accumulate in the dermis and be more or less toxic. When inhaled, TiO2 leads to exposure of the lungs. ANSES (French Agency for Food, Environmental and Occupational Health & Safety) classifies it as a proven carcinogen and ECHA (European Chemicals Agency) as a suspected carcinogen. In this context, the Organic Cosmetic Standards (Cosmébio and Cosmos) prohibit nanoparticles in beauty products, except in sun creams, due to a lack of substitutes.
Their impact on the environment:
The issue of nanoparticle dissemination in ecosystems is also a concern. Indeed, cosmetics rinsed off in the shower or sun creams that settle in the sand and sea result in the presence of nanoparticles in oceans, lakes, rivers, etc... Studies on the ecotoxicity of TiO2 nanoparticles are few compared to other nanomaterials, but initial results urge caution, particularly due to their harmful impact on phytoplankton, an organism at the base of the marine food chain.
In this context, Typology prefers toapply the principle of caution and does not introduce nanoparticles into its formulas.
Sources:
CROSERA M. & al. Nanoparticles skin absorption: New aspects for a safety profile evaluation. Regulatory Toxicology and Pharmacology. (2015).
ZHONGHUA C. et al. TiO2 nanoparticles in the marine environment : Physical effects responsible for the toxicity on algae. Phaeodactylum tricornutum. Science of the Total Environment (2016).
