Harmonised classification of titanium dioxide

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Industry fought hard against the harmonised classification of titanium dioxide as a carcinogen. With the publication in the EUs Official Journal, they will have to adapt to it.

Check out our handy glossary of definitions and abbreviations of technical terms used in this article.

What has happened?

The CLP Regulation (1272/2008) [1] has been amended by Regulation 2020/217 [2] (commonly known as the 14 ATP) to include a mandatory, harmonised classification for titanium dioxide as a carcinogen [carcinogenicity, Category 2 (by inhalation) (Carc 2, H351i].

Unusually, the classification is limited to a specific form of the substance, ie fine powder containing 1 % or more of particles with aerodynamic diameter ≤ 10 μm. This means that if the substance is not in this specific form, the classification does not apply.

However, some products containing other forms of titanium dioxide will have to include new warnings on the product label.

• For liquid mixtures containing 1 % or more of titanium dioxide particles with aerodynamic diameter ≤10 μm: EUH211: ‘Warning! Hazardous respirable droplets may be formed when sprayed. Do not breathe spray or mist.’
• For solid mixtures containing 1 % or more of titanium dioxide: EUH212: ‘Warning! Hazardous respirable dust may be formed when used. Do not breathe dust.’

Solid mixtures containing more than ≥ 1% of the fine-powder form of titanium dioxide should normally be classified as Carc 2, H351i, according to the generic concentration limit of the CLP Regulation.

The Regulation was published the Official Journal of the European Union in February 2020. The classification and labelling becomes mandatory on 9 September 2021, although suppliers may (and perhaps ought) to use them before that date.

Why is it important?

Titanium dioxide is a whitening agent used very widely in products such as paper, paints, ceramics, textiles and cosmetics (notably in suncreams). Industry strenuously opposed the classification, and has outlined potential consequences of the new classification and labelling:

  • Waste disposal and recycling might be seriously affected, because wastes containing 1% or more titanium dioxide may be classified as hazardous waste;
  • To avoid classification or labelling that might impact sales, paint formulators may decrease the concentration of titanium dioxide, leading to less effective products;
  • Food spoilage may increase as titanium dioxide is used in plastic packaging of food;
  • EU industry might become less internationally competitive, if non-EU countries do not adopt the same hazard classification;
  • Products containing titanium dioxide may become ineligible for eco-labels, because carcinogens are often not allowed.

Furthermore, industry argued that carcinogenic classification of titanium dioxide was not scientifically justified:

• The carcinogenic hazard was determined in animal studies with prolonged inhalation of high quantities, unlikely to be realised in real-life situations
• The carcinogenic hazard might be a generic property of water-insoluble dusts (so-called poorly soluble, low toxicity, PSLT; includes carbon black), and not be specific for the substance.
• Epidemiological and other data for humans do not show significant safety issues for carcinogenicity.

The Commission concluded that such objections were not substantial enough to overturn the Risk Assessment Committee’s (RAC’s) opinion.

Our view

Classification of substances is traditionally regarded as purely hazard based, according to criteria given in the CLP Regulation.

For a Category 2 carcinogen, the criteria include limited evidence of carcinogenicity in animals, with the data suggesting a carcinogenic effect, but limited for making a definitive evaluation, for example if there are questions regarding the interpretation of the studies.

On this basis, the criteria for classification are fulfilled, and it is surprising that many of the objections raised by industry during the consultation process were commercial (eg consumer alarm at new labelling), or related to low-exposure use (ie risk assessment).

However, the classification process should account for the ‘forms or physical states’ (CLP Articles 5 and 6) in which the product is placed on the market, and is expected to be used. So there is precedent for classifying different particle sizes, or mixture forms (solid or liquids) differently.

At Alchemy, we are often asked whether a hazard classification applies to a particular product form. The most common scenario is exactly that demonstrated by titanium dioxide products: does a solid ingredient with an inhalation hazard, confer that hazard to a liquid product, which is essentially non-inhalable?

Our interpretation is that the assessor should classify the liquid product for the inhalation hazard, unless they can be sure that the product spray or ingredient dust (from drying out) is not formed during the lifetime of the product.

The new listing for titanium dioxide demonstrates that the EU authorities have a similar interpretation. Titanium dioxide has a carcinogenic classification for certain forms, and liquid products require special labelling to protect users from a perceived inhalation risk (through dusts or mists) of the solid ingredient.

Industry would have preferred the risk to be controlled through an EU occupational exposure limit (OEL).

Harmonised classification and labelling for titanium dioxide

The full listing for the CLP Regulation, Annex VI, is given below.

Titanium dioxide [in powder form containing 1% or more of particles with aerodynamic diameter ≤ 10 μm] (EC 236-675-5; CAS 13463-67-7).

Classification: Carc 2, H351 (inhalation).

GHS08 Health Hazard
Warning
Suspected of causing cancer by inhalation.
Note V:
If the substance is to be placed on the market as fibres (with diameter < 3 μm, length > 5 μm and aspect ratio ≥ 3:1) or particles of the substance fulfilling the WHO fibre criteria or as particles with modified surface chemistry, their hazardous properties must be evaluated in accordance with Title II of this Regulation [Hazard Classification, including forms or physical states in which the mixture is placed on the market], to assess whether a higher category (Carc 1A or 1B) and/or additional routes of exposure (oral or dermal) should be applied.
Note W:
It has been observed that the carcinogenic hazard of this substance arises when respirable dust is inhaled in quantities leading to significant impairment of particle clearance mechanisms in the lung.
This note aims to describe the particular toxicity of the substance; it does not constitute a criterion for classification according to this Regulation.
Note 10:
The classification as a carcinogen by inhalation applies only to mixtures in powder form containing 1% or more of titanium dioxide which is in the form of or incorporated in particles with aerodynamic diameter ≤ 10 μm.

Furthermore:

Mixtures containing titanium dioxide:

The label on the packaging of liquid mixtures containing 1 % or more of titanium dioxide particles with aerodynamic diameter equal to or below 10 μm shall bear the following statement: EUH211: ‘Warning! Hazardous respirable droplets may be formed when sprayed. Do not breathe spray or mist.’
The label on the packaging of solid mixtures containing 1 % or more of titanium dioxide shall bear the following statement: EUH212: ‘Warning! Hazardous respirable dust may be formed when used. Do not breathe dust.’

References

[1] Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures (as amended). [back]

[2] Commission Delegated Regulation (EU) 2020/217 of 4 October 2019 amending, for the purposes of its adaptation to technical and scientific progress, Regulation (EC) No 1272/2008 of the European Parliament and of the Council on classification, labelling and packaging of substances and mixtures and correcting that Regulation. [back]