Quality inspection departments at all levels are responding to calls to inspect egg-related businesses after traces of an industrial dye were found in duck's eggs.

The General Administration of Quality Supervision, Inspection and Quarantine released a notice yesterday saying inspections will test for all kinds of Sudan Red colorants, including Sudan Red I, II, III and IV, all of which are carcinogenic industrial dyes strictly banned in the food industry.

The contamination scare started after CCTV reported last weekend that ducks in Hebei Province had been fed Sudan Red IV to make the yolks of their eggs more red. Any producers found to have added Sudan Red to duck feed will have to stop producing and distributing the eggs and will also face temporary closure. Further, such operations will also be obliged recall any tainted eggs.

The Hebei Quality Supervision, Inspection and Quarantine Bureau has been told to seize all salted duck eggs suspected of containing the dye at Hebei's Baiyangdian Guohua Egg Processing Plant, the source of the contamination, and to carry out additional sample tests and inspections.

To date, six of the 22 different brands of eggs that have been tested in the capital contained Sudan Red IV. Five of those brands originated in Hebei Province, the final brand in Central China's Hubei Province.

The Beijing Administration for Industry and Commerce announced these findings yesterday morning after a thorough investigation of local distribution centres, production facilities and catering enterprises. The Beijing administration had seized 1,158 kilograms of duck eggs suspected of contamination by Monday night.

Beijing's food safety office has launched investigations into the enterprises involved in the case and has cut off the importation channels.

Officials in Anxin and Jingxing counties in Hebei, the major sources of the contaminated eggs, have been detained, sources at the Hebei Provincial Food and Drug Bureau said.

In Beijing, sales of salted duck eggs have plummeted. Xinfadi Market sold 80 per cent fewer eggs on Monday.

Though no Baiyangdian brand duck eggs have turned up in Guangzhou and Tianjin, local authorities there have called for all red-yolked duck eggs to be removed from shelves. Restaurants have also been told to stop using such eggs until after further notice.

Chen Zejun, president of the Guangzhou Food Association, said Guangzhou consumes about 25 tons of salted duck eggs a day, primarily as an ingredient in cakes and Cantonese-style cuisine.