TiO₂ Masterbatch: Understanding Opacity, Whiteness, and Food-Contact Compliance

How TiO₂ loading affects opacity and CIE whiteness index — and what food-contact compliance (EU 10/2011, FDA) means in practice.

White masterbatch based on Titanium Dioxide (TiO₂) is among the most widely used masterbatch types in plastics processing. It is used in packaging film, injection-moulded closures, fibres, and countless other applications. But not all white masterbatches are equal — understanding TiO₂ loading, particle size, and regulatory compliance is essential to selecting the right grade for your application.

Why TiO₂?

Titanium Dioxide is the most effective white pigment available — it has an exceptionally high refractive index (2.7 for rutile grade), which means it scatters visible light very efficiently. A small amount of TiO₂ produces a high degree of opacity (hiding power) and a bright, neutral white colour. No other white pigment approaches TiO₂ in opacity per unit weight.

How Loading Affects Opacity

TiO₂ masterbatch is typically produced at 50–70% TiO₂ loading. The opacity of the finished plastic part depends on both the masterbatch loading level and the let-down ratio (dosage rate). Higher dosage or higher TiO₂ loading in the masterbatch produces greater opacity — but above a certain threshold, the relationship becomes non-linear due to light scattering interference between closely-spaced pigment particles (this is called "optical crowding").

For packaging film applications, a dosage of 4–8% white masterbatch (at 50–60% TiO₂ loading) typically achieves opacity levels of 85–95%, suitable for most packaging requirements. Exact dosage depends on film thickness, TiO₂ particle size distribution, and the required CIE whiteness index.

Food-Contact Compliance

For applications that contact food — packaging, closures, containers, food-service items — the masterbatch must comply with applicable food-contact regulations. The two most relevant frameworks are EU Regulation 10/2011 on plastic materials intended to contact food, and FDA 21 CFR (US Food and Drug Administration Code of Federal Regulations).

Not all TiO₂ grades are food-contact compliant — some pigment grades, carrier additives, or processing aids used in masterbatch production may not be approved for food contact use. When sourcing white masterbatch for food-contact applications, always request explicit confirmation of compliance and ask for the relevant Declaration of Compliance (DoC).

Through the Coraplast range distributed by Blau Batch, food-contact compliant white masterbatch grades are available. Contact us with your application details and we will provide the appropriate grade and compliance documentation.

Continue Reading