Int'l Food Experts Set 'Tolerable' Level for Melamine Intake at WHO-Sponsored Meeting

December 17, 2008 // Published as a news service by IHS

The TDI is lower than previous TDIs suggested for melamine by some national food safety authorities, according to WHO.

"We expect this could better guide the authorities in protecting the health of their public," said WHO Director for Food Safety, Dr. Jørgen Schlundt, at the closing of the WHO meeting.

The international experts gathered by WHO did not set a "safe" level of melamine but they established a tolerable level.

Melamine is a contaminant that should not be in food, said WHO. However, sometimes it is unavoidable.

The TDI represents the tolerable amount of unavoidable contaminant in food that a person can ingest on a daily basis without appreciable health risk. The TDI is meant to help national authorities set safe limits in food for withdrawal purposes should melamine be detected as a result of intentional adulteration, said WHO.

The TDI for melamine was established at 0.2 milligrams (mg)/kilogram (kg) body weight. Based on this, it leads a 50 kg person to a tolerable amount of 10 mg melamine per day, said WHO.

The TDI applies to melamine alone. The TDI for cyanuric acid alone remains at 1.5 mg/kg body weight. Co-occurrence of melamine with cyanuric acid seems to be more toxic, said WHO. However, adequate data are not available to allow the calculation of a health-based guidance value for this coexposure.

"At the same time the limits for melamine in infant formula (1 part per million or ppm) and in other foods (2.5 ppm) introduced by many countries provide a sufficient margin of safety as compared to the TDI," said Schlundt. Twenty-one experts attended the meeting to review toxicological aspects of melamine and cyanuric acid.

Melamine contamination in China
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, according to WHO.

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, said WHO.

The Chinese Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) reportedly found levels of melamine in dairy products (including infant formula) that ranged between 0.09 to 6196.61 mg/kg.

In food processing ingredients such as egg yolk and egg albumen powder, the levels found ranged between 0.1 to 5.03 mg/kg. Fresh eggs produced in China were also 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 Special Administrative Region, reported levels of 6.6 mg/kg in a brand of animal feed produced in mainland China, said WHO. Due to the contamination that happened in China, various countries also initiated the performance of melamine tests in products that originate from China or that were 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 was also reported to contain melamine traces in amounts that ranged between 61 to 797 mg/kg.

Source: World Health Organization (WHO).