Laboratories in Europe and the US have witnessed a step up in demand for the tests since the detection of Sudan in a batch of Worcester sauce earlier this year sparked off the biggest food recall ever in the UK's history.
Supplied by the St.Albans-based firm Premier Foods to both retail and industrial ingredient markets, over 600 well-known processed food products were pulled from the shelves.
Estimates for the cost of the recall, that includes sales loss, destruction, management time, and consultants fees plus the 'softer' costs like brand damage, are rolling in excess of €200 million.
In today's complex food chain, food firms are faced with greater risk of contamination, compounded by the global sourcing of food ingredients.
Sudan I - used for colouring solvents, oils and petrol for example - is an illegal colour under the Colours in Food Regulations 1995. Considered to be a genotoxic carcinogen its presence, at any level, is not permitted in food for any purpose.
The European Commission first notified exporting countries of chilli, notably India, as far back as June 2003 that consignments of hot chilli and hot chilli products imported into the EU for human consumption, should be accompanied by an analytical report demonstrating the consignment was free of Sudan I.
The EU has since expanded the scope of notification to cover Sudan II, Sudan III and Scarlet Red (Sudan IV).
That the contaminated chilli powder slipped into the Worcester sauce unnoticed suggests a gap in testing, somewhere in the supply chain.
US contract research and development firm The National Food Laboratory (NFL) has developed a new method to test for the presence of Sudan dyes in both raw spice material, such as paprika, tumeric and oleoresins, and blended material products.
"Our current method can detect all four types of Sudan dyes at 0.01 ppm in a variety of sample matrices," says Julie Hill, vice president of chemistry at The NFL.
Nervous that a Sudan 'repetition' could be on the way, food makers have raced to contact the food laboratories to establish the availability and efficacy of tests, anxious to minimise risk.
"In terms of due diligence, it is appropriate for a food manufacturer or ingredients company to test each batch of raw ingredients, such as spices or palm oil, before using in compound products," says Ian Gatsby at UK testing laboratory RSSL, that also offers a sudan test.