The discovery of a carcinogenic parasiticide in fish sold in Henan Province has prompted a demand for nationwide inspections, but Beijing authorities said laboratory tests will not be possible for another two weeks.

Malachite green was found in fish at the Liulin seafood market in Zhengzhou, Henan's capital, and traced back to suppliers from neighboring Hubei Province, according to a Ministry of Agriculture notice on July 7.

It said the suspect fish are sold mainly in Beijing, Tianjin, Shanghai as well as in Henan and Jiangxi provinces, and called for local departments to carry out checks for the chemical, banned from food products in 2002.

Today's China Daily reported that the ministry issued reassurances to the public on Tuesday, and a statement from the fishery bureau is expected today.

Beijing's Food Safety Office said a survey will be conducted as soon as possible on the capital's fish markets once an inspection reagent is available, but because they do not normally test for it this will take two weeks.

The city's Entry-Exit Inspection and Quarantine said it was going to meet to discuss the issue and is trying to buy reagents abroad, which is expected to take three weeks.

Six weeks ago, the UK Food Standards Agency said it had found unacceptable levels of the chemical in organically farmed salmon sold in Morrisons, a large supermarket chain there, and there have been reports of similar finds in Slovakian rainbow trout a fortnight ago.

Malachite green (also called aniline green) has been used to treat parasites, fungal infections, and bacterial infections in fish and fish eggs. It is banned in aquaculture in many countries for being highly toxic.

According to industry insiders, most fish transporters use malachite green to disinfect their transporting vehicles for higher fish survival rates. Many live fish storage facilities and hotels also use it to keep fish alive for longer. Its use also means that dead fish are preserved, and can be mistaken for being alive and motionless.

(China.org.cn by Wind Gu, July 13, 2005)