Testing on Pigments and Dyes

Pigments and dyes make the products of daily life colourful and attractive for consumers. Dyes are commonly soluble in a certain media while pigments are insoluble. Pigments and dyes in food contact applications are mainly applied as colourant like masterbatches or as components of printing inks. Both applications are not covered by harmonised European legislation.

European Plastic Regulation (EU) No. 10/2011 acknowledges the use of colourants subject to the national legislation. Nevertheless, the national legislation on pigments and dyes is also barely in place.

The Netherlands Commodities Act (Warenwet) on packaging and consumer articles defines the requirements on colourants which are mainly adopted from the Council of Europe Resolution from AP (89)1:

• Heavy metals soluble in 0.1 N hydrochloric acid
  • antimony: 0.05%
  • arsenic: 0.01%
  • barium: 0.01%
  • cadmium: 0.01%
  • chromium: 0.1%
  • mercury: 0.005%
  • lead: 0.01%
  • selenium: 0.01%
• Content of Primary Aromatic Amines shall be below 500 mg/kg
• Content of Sulfonated Aromatic Amines shall be below 500 mg/kg
• Content of Polychlorinated Biphenyls shall be below 25 mg/kg
• Toluene extractable fraction of carbon black pigments shall be below 0.15%

However, the industry usually applies stricter limits as the above listed limits are quite high owing to the age of the Resolution dated in 1989.

Furthermore, pigments and dyes must be properly incorporated in the final packaging, ensuring thereby that no transfer of colourants to food may occur.