Titanium Dioxide Classified as Potential Class 2 Carcinogen in Europe? The Future for Chinese Cosmetics Regulations

The European risk committee of European Chemicals Agency (ECHA) has proposed that Titanium Dioxide (TiO2) be classified as a class 2 carcinogen. Although it is still in the proposal stage, this potential classification will have a significant impact on worldwide cosmetic ingredient regulation.

What is TiO2 & How is TiO2 used in cosmetics?

Titanium dioxide is a naturally occurring mineral that is mined from the earth then further processed and purified for use in consumer products. Also known as titanium (IV) oxide or titania, it is the naturally occurring compound comprised of the metal titanium and oxygen. Titanium dioxide is safely used in many products from paint and food to drugs and cosmetics.  

TiO2 is used in a variety of cosmetics including sunscreens, pressed powder, loose powders, eye shadows and blush as UV filter or whitening agent. When used as Whitening agent, TiO2 helps to increase the opaqueness and reduce the transparency of product formulas; when used as UV filter, TiO2 is an important active ingredient to absorb, reflect or scatter light (including ultraviolet radiation from the sun).

TiO2 is processed into many different sizes, which have different properties. Micronized TiO2 (also called "nano") was introduced in the early 1990s, and used in many OTC sunscreen products. Use of this ultrafine material enables the sunscreens to be applied as a clear film that consumers prefer over the antiquated, white opaque lotions.

History of EU regulating TiO2                                     

Because TiO2 is widely used in cosmetics as a whitening colorant and UV filter, if designated as a class 2 carcinogen, many cosmetic manufacturers will have to adjust their formulas. And if EU revises its standard for TiO2 in cosmetics, other countries and regions may accordingly revise their requirements, or REACH compliance for cosmetics with TiO2 between EU and other countries will become more complicated.

Over the last several years the EU has constantly assessed the risk of TiO2 and based its standard for TiO2 in cosmetics upon these results. In 2013, the EU's Scientific Committee on Consumer Safety (SCCS) issued an opinion on the safety of nanoscale titanium dioxide particles used as sunscreens. The SCCS finally acknowledged that nanoscale particles of titanium dioxide do not penetrate the skin and concluded that their use at concentrations up to 25% as UV filter in sunscreen does not pose any risk of adverse effects in humans after application on healthy, intact or sunburnt skin.

However, when TiO2 is inhalable—as it may be in powders—it is considered a possible carcinogen by the International Agency for Research on Cancer (IARC). TiO2 is classified as an IARC Group 2B carcinogen, meaning it is possibly carcinogenic to humans. The findings of the IARC are based on the discovery that high concentrations of pigment-grade (powdered) and ultrafine titanium dioxide dust caused respiratory tract cancer in rats exposed by inhalation and intratracheal instillation. The series of biological events or steps that produce the rat lung cancers (e.g. particle deposition, impaired lung clearance, cell injury, fibrosis, mutations and ultimately cancer) have also been seen in people working in dusty environments.

Concerns revolving around the potential to impact human health recently culminated in 2017 when the Risk Assessment Committee of the European Chemicals Agency (ECHA) officially proposed TiO2 as a potential class 2 carcinogen. Considering the conclusion from ECHA, EU may revise its restriction of TiO2 in cosmetics in the future.

Currently, titanium dioxide is allowed for use as a cosmetic colorant in the European Union without restriction when purity requirements are fulfilled (Details see EU CosIng), and when TiO2 approved as sunscreen ingredient, it may be used at concentrations up to 25% (Details see EU CosIng). When used as a colorant in cosmetic products in the European Union, this ingredient must be called CI 77891. For TiO2 of nanoscale, it is not allowed to use in application that may lead to exposure of the end-user's lungs by inhalation unless:

— purity ≥ 99 %;

— rutile form, or rutile with up to 5 % anatase, with crystalline structure and physical appearance as clusters of spherical, needle, or lanceolate shapes;

— median particle size based on number size distribution ≥ 30 nm;

— aspect ratio from 1 to 4,5, and volume specific surface area ≤ 460 m2/cm3;

— coated with Silica, Hydrated Silica, Alumina, Aluminium Hydroxide, Aluminium Stearate, Stearic Acid, Trimethoxycaprylylsilane, Glycerin, Dimethicone, Hydrogen Dimethicone, Simethicone;

— photocatalytic activity ≤ 10 % compared to corresponding non-coated or non-doped reference;

— nanoparticles are photostable in the final formulation (Details see EU CosIng).

EU's ingredient standard deeply influence cosmetics regulation in China

EU's cosmetic ingredient standards (in European Commission (EC) of cosmetic products) have long influenced cosmetic regulations in China and the rest of Asia. Current Chinese cosmetic ingredient standards are formulated partially on the basis of EU standard. Looking up to Inventory of Existing Cosmetic Ingredients in China (IECIC 2015), and List of Permitted Sunscreens Used in Cosmetics in China, requirement of TiO2 using in cosmetics in China is the same as EU's: unlimited use as colorants and maximum concentration of 25% in sunscreens. In Taiwan district, recent amendment of TiO2 standard in cosmetics has also taken EU standard as reference: cosmetics containing TiO2 within 25% (if contain both TiO2 and Nano TiO2, the total concentration not exceeding 25%) are designated as general cosmetics and don't require registration (details see CL).

If the European Commission changes the requirements of TiO2 in cosmetics according to ECHA's conclusion (class 2 carcinogen), it can be assumed that China will follow the EU new standard and change the requirement of TiO2 either. There are plenty of history instances where China revised or restricted the use of high risk substances in cosmetics based on EU standards. China revised its Cosmetic Technical and Safety Standard in 2015 (Regulation includes list of prohibited/restricted ingredients and list of permitted ingredients). In this revision, China restricts lead in cosmetic from 40mg/kg to 10mg/kg because EU regulates lead in cosmetics requiring 10mg/kg as maximum concentration. The same thing happened to arsenic that EU regulates arsenic in cosmetics requiring 2mg/kg as maximum concentration so China revised the restriction of arsenic from 10mg/kg to 2mg/kg. Another example is asbestos, a carcinogen, which was banned in EU. China banned asbestos since 2015 after referring to European Commission (EC).

Prediction

It is still just a proposal of ECHA's to classify Titanium Dioxide as class 2 carcinogen, and it is still too early to predict any amendment to regulations. Before EU revises the requirement of TiO2, there will be little impact on manufacturing or importing of cosmetics using TiO2. Considering TiO2 is widely used in color cosmetics and sun-protection products, it is difficult to entirely ban this substance. If EU reduces the maximum concentration of TiO2 in cosmetics, China and Asia will presumably follow the standard, therefore trade of cosmetics using TiO2 between EU and Asia won't be affected that much.

In the future, how would EU regulate TiO2? Take aloe for example, the US classified Aloe Vera Whole Leaf Extract a carcinogen. The US doesn’t ban it but does require any product containing aloe manufactured in or imported to the US to be labeled with "aloe may cause cancer" on containers/packages. It is uncertain if EU will regulate TiO2 in this way, but it is a possible direction.