Titanium Dioxide Classification

The European Commission (EC) plans to advance its proposal to classify titanium dioxide (TiO2) as a ‘Carcinogen category 2.’ This move follows the September 18 CARACAL meeting, where authorities discussed REACH and CLP regulations. The classification highlights an inhalation hazard, marked by the code H351 (inhalation).

This classification will affect liquids and powders containing 1% or more titanium dioxide. It specifically applies to mixtures with particles that have an aerodynamic diameter of ≤ 10 µm.

The EC has now submitted this act to the European Parliament and Council, and it has officially taken effect. This decision follows France’s 2019 announcement banning TiO2 in food, effective January 1, 2020.

 

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Intensifying Discussion on Titanium Dioxide Classification

The debate around titanium dioxide (TiO2) has intensified since the European Chemicals Agency (ECHA) Committee for Risk Assessment published its opinion on TiO2 classification and labeling. In response, 300 industry stakeholders requested “full clarity” to complete and assess the impact of the Commission’s proposal.

Many industries and users believe that TiO2 hazards stem from particle size rather than the substance itself. This concern raises questions about similar risks for other poorly soluble, low-toxicity particles capable of forming respirable dust. Critics also point out that TiO2 incorporated into a matrix likely poses minimal human exposure risk.

This classification may create uncertain effects for downstream users and could impede recycling efforts. Waste containing 1% or more TiO2—like plastics, wallpaper, paint residues, porcelain, and furniture—will require additional waste management. These materials would classify as hazardous waste, even without a real risk of inhalation.

The EC announcement specifies TiO2 particles with an aerodynamic diameter of ≤ 10 µm at a 1% concentration. However, it remains unclear if this classification refers to a volume-based or number-based size distribution. This ambiguity underscores the need for further clarity in the regulatory framework.

Titanium Dioxide Classification and Respiration

Small particles, like titanium dioxide (TiO2), often enter the human body through the lungs. Additionally, fine dust particles can negatively impact the eyes. The health effects of these particles depend on factors like size, shape, solubility, and toxicity. For example, when sodium chloride (table salt) enters the lungs, it poses minimal concern; it dissolves easily in moisture and exits the body. In contrast, asbestos, although not inherently toxic, has a needle-like shape, is insoluble, and non-biodegradable, making it extremely dangerous.

Producers and manufacturers must actively control dust emissions. This responsibility stems from health, safety, and environmental concerns, along with increasingly stringent quality standards from customers. Regulatory bodies, such as the European Food and Safety Authority (EFSA), the Environmental Protection Agency (EPA), and the UK’s Health and Safety Executive, are intensifying dust emission regulations.

The REACH program further regulates materials produced or sold in quantities over 1,000 kilograms annually in Europe. Compliance with these regulations is vital for maintaining safety and product quality across industries. By effectively managing dust emissions and meeting these guidelines, companies protect public health, preserve the environment, and fulfill regulatory obligations.

Usages of titanium dioxide

Titanium dioxide (TiO2) is widely utilized across various industries, particularly in the pigment and paints sector. In addition to its role in paints and pigments, TiO2 serves as a filler in products such as specialty papers, ceramic materials, and inks. It is also found in cement, correction fluid, rubbers, elastomers, and glass.

Furthermore, TiO2 is a key ingredient in skin care products, including sun creams. Its UV-active properties enable it to absorb and reflect ultraviolet rays effectively, making it essential for sun protection formulations. Additionally, TiO2 is commonly used in plastics production, enhancing various properties and overall performance.

In the food industry, titanium dioxide is designated as E171. It primarily appears in products such as toothpaste, chewing gum, and medicines. Beyond its role as a coloring agent, TiO2 exhibits valuable photocatalytic properties. When exposed to ultraviolet light, it can break down nearly all organic compounds present in both air and water. This capability is especially useful for applications requiring purification and degradation of harmful substances.

Overall, titanium dioxide plays a crucial role in a wide array of products and industries, showcasing its versatility and importance in modern applications. Its unique properties make it an invaluable component across many sectors, from consumer goods to industrial applications.

Understanding Aerodynamic Diameter in Particle Measurement

With the new legislation, we must understand the aerodynamic diameter of airborne particles. These particles often have irregular shapes, and their aerodynamic behavior is represented by the diameter of an idealized spherical particle, known as the aerodynamic diameter. We rely on this diameter for particle sampling and description, commonly referred to as particle size.

It is crucial to note that particles with the same aerodynamic diameter can have different dimensions and shapes. Currently, measuring aerodynamic diameter directly as a single parameter using one technique is not straightforward. However, we can effectively use the EN 15051 dustiness potential measurement device. This device provides quantitative information on the inhalable, thoracic, and respirable fractions of airborne particles. The respirable fraction is particularly important for quantifying particles smaller than 10 µm.

Once we collect this dust fraction, we need to assess the TiO2 content. Specifically, we must determine whether its mass percentage exceeds 1%. When employing laser diffraction to measure particle size distribution, we must correct the results by measuring the true density of the material. We will recalculate the measured data to a normalized density of 1 g/cm³ for accurate aerodynamic diameter determination.

However, this correction is only an approximation and may not fully reflect reality. The assumption that an ideal particle dispersed in air is perfectly spherical is often inaccurate. This discrepancy highlights the challenges in accurately measuring aerodynamic diameter and emphasizes the need for careful analysis in particle characterization.

Investigating New Nano Dust Measuring Methodology

We are currently exploring a newly accepted nano dust measuring methodology outlined in EN-17199-4. Our goal is to develop testing and measuring equipment based on this standard. Although the methodology is standardized, no commercially available products currently meet these direct measurement needs.

By investigating this new approach, we aim to create equipment that accurately assesses nano dust across various applications. This development will enhance our testing capabilities and ensure compliance with the latest regulatory requirements. We believe this initiative will significantly benefit our clients and advance research in nanoparticle analysis.