This TDI for melamine has been set at 0.2 mg/kg body weight (bw) and is the outcome of a meeting organized by the World Health Organisation (WHO) this week in Ottawa, Canada.
The WHO said that based on this TDI, a 50 kg person could tolerate 10 mg melamine per day.
The international experts gathered by WHO said that they have not set a ‘safe’ level of melamine but they have established a ‘tolerable’ level:
“Melamine is a contaminant that should not be in food. However, sometimes it is unavoidable. TDI represents the tolerable amount of unavoidable contaminant in food that a person can ingest on a daily basis without appreciable health risk.”
Lower intake level
This TDI is lower than previous TDIs suggested for melamine by some national food safety authorities; the EU’s standard for melamine is set at 0.5 mg.
The WHO said that the new 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.
"We expect this could better guide the authorities in protecting the health of their public," said WHO director for food safety, Dr Jørgen Schlundt.
He added that 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.
Toxic chemical
Melamine is an industrial chemical that can be found in cleaning supplies; it is used as fertilizer, can be used on processing plant equipment and is often found in plastic packaging.
The chemical is toxic and can cause kidney stones, kidney disease, other organ problems and kidney failure, often fatal in children.
Four babies died in China and approximately 53,000 children became ill after consuming milk powder tainted with melamine.
Infant formula
In October, the US Food and Drug Administration (FDA) said it was unable to set a safe level of melamine contamination in infant formulas after issuing a wider ruling on the chemical’s presence in food products containing milk.
As part of a scientific safety and risk assessment of the chemical, the regulator used both available data and scientific assumptions to ascertain a level where the chemical is a long-term health hazard.
As part of the interim findings, any food product other than infant formula that contains less than 2.5 parts per million (ppm) of the industrial chemical does not pose safety risks for consumers, the regulator said.
However, the FDA claimed that establishing a limit on the chemical’s presence in infant formula was currently impossible, owing to uncertainty over the specific impacts of melamine in an infant’s body.
The regulator added that this did not necessarily suggest that any exposure to the chemical in infant formula would definitely harm infants, but that there was too much uncertainty to outline specific guidelines for consumers.
Uncertainty
According to the FDA, this uncertainty has been created by a number of specific factors related to infant formula and their consumption. These include:
- The consequences of continuous use of infant formulas as a sole nutrition source
- Unknown impacts of the presence and co-ingestion of different types of melamine
- Premature infants with immature kidney infections that have been kept solely on formula resulting in a greater levels of intake over a longer time than term infants