Ultramarine pigments for food contact plastics

 By Dave Masterman, Holliday Pigments
 Synthetic Ultramarine is non-toxic and inherently safe for sensitive applications including cosmetics, children's toys and plastics that come into contact with food stuffs. Holliday Pigments has added value to plastic packaging by developing a grade that was proven to impart no taste or odour during the production process. Launched in Europe in 2006, the technology is now becoming popular in China, Japan and Southeast Asia, where customers are realising the benefits of working with the very best raw materials for more demanding end uses.

 Industrial developments
 In the quest for improved productivity, injection moulders are always trying to reduce cycle times, which invariably means using high process temperatures and shear rates,– putting polymers and colourant additives under more extreme manufacturing conditions.
 Ultramarine blue's unique colour is only possible because of sulphur anions within its crystal lattice. Under extreme moulding conditions, where the pigment is exposed to high temperatures and shear rates, incorrect grade selection could lead to sulphurous taint in certain beverages. Whilst there are many factors that could contribute to this issue, Holliday Pigments has improved its manufacturing process to specifically enable the production of pigments, proven to transfer no detectable taste to liquids contained in plastics packaging. Though the company's standard Ultramarines have worldwide health and safety approvals for such applications, this added-value benefit offered its customer base new packaging options at the premium end of the market – capitalising on designer bottled drinks, for example.
 Developing raw materials that are proven to minimise their organoleptic effects in food contact applications represented an important development at this time and the resulting Premier BC for still water and BC-R for carbonated soft drinks have since been widely specified across the heavily regulated European and US food and beverage sectors. Now, with health and safety issues coming increasingly to the fore at a global level, markets which have traditionally been more cost-driven are actively seeking certified products with proven performance benefits to enhance their competitive edge.

 egulatory directives
 Most countries have their own systems of approval, often based on the two most commonly accepted regulations, – those of Europe and the USA. Pigments used for colouring food contact plastics in the European Union are required to meet the purity standards listed in Resolution AP(89)1. Another regulation deals with substances in plastics other than pigments which may come into contact with foodstuffs -- Directive 2002/72/EC. Even whilst the Ultramarine pigment itself is not subject to this regulation, any additives, such as the carrier used in Holliday Pigments' Prestige series of low dust preparations, must meet its requirements.
 Pigments used for colouring food contact plastics in the USA are required to be on an approved list. Until recently, the list was non-proprietary and identified only the pigment, not the manufacturer. The regulation is published in the Code of Federal Regulations, Title 21, Part 178.3297. Being a well established pigment, Ultramarine has long been included in this list. The approvals process has since changed and new pigments are approved under the Food Contact Notification program, which identifies both the pigment and the manufacturer. Although Ultramarine pigment sarelisted in 178.3297 on the FDA website, there is an additional purity restriction. This necessitates that the pigment should meet the requirements of Title 21 Part 73.2725, which establishes limits for the content of lead, mercury and arsenic for UlKD VIII N7 Glowing