Presentation of melamine
Melamine is a chemical compound that has a number of industrial uses, including the production of laminates, glues, dinnerware, adhesives, molding compounds, coatings and flame retardants. Melamine is a name used both for the chemical and for the plastic made from it. In this event, all references are to the chemical. There are no approved direct food uses for melamine, nor are there any recommendations in the Codex Alimentarius. Melamine is illegally added to inflate the apparent protein content of food products. Because it is high in nitrogen, the addition of melamine to a food artificially increases the apparent protein content as measured with standard tests.
Source of the contamination
In this event, contamination appears to have happened as fraudulent contamination in primary production. Chinese government officials have pinpointed milk collecting stations as the sites where the melamine was added. According to Sanlu, contaminated milk was used in the manufacture of powdered infant formula processed before 6 August 2008 and the tainted milk powder has also been used in the manufacture of a number of other products.
The Chinese Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) has reported to have found levels of melamine in dairy products (including Infant Formula) that ranged between 0.09 to 6196.61 mg/kg. In food processing ingredients (i.e. egg yolk, egg albumen powder, etc.) the levels found ranged between 0.1 to 5.03 mg/kg. Fresh eggs produced in China have also been found to be contaminated with the chemical compound at levels that ranged between 3.1 to 4.7 mg/kg. The Center for Food Safety, Hong Kong SAR, has reported levels of 6.6 mg/kg in a brand of animal feed produced in mainland China.
Due to the current event various countries had also initiated the performance of melamine tests in products that originate from China or that had been manufactured using Chinese ingredients. The official levels reported by national authorities ranged between 0.38 to 945.86 mg/kg for dairy products. For processed foodstuff and food processing ingredients the levels ranged between 0.6 to 6694 mg/kg. Animal feed manufactured in China has also been reported to contain melamine traces in amounts that ranged between 61 to 797 mg/kg.