The Shanghai Food and Drug Administration-imposed ban on crayfish washing powder this week must have come as a big blow to millions of crayfish eaters and vendors in the country.

The unlabelled washing powder, which contains illegal and suspicious ingredients that the SFDA is still investigating, has been used widely in the country's restaurants and food stalls to clean the dirty freshwater crustacean. Previous methods of sprucing the crayfish with a brush are not only time consuming, but also expose workers to attacks from the vicious pincers.

Crayfish soaked in washing powder for barely 10 minutes looks more appealing and sells for a higher price in the market. Yet, its possible health hazards are shocking, considering its popularity.