For infant formula, the safety/risk assessment concludes that at this time FDA is unable to establish any level of melamine and melamine-related compounds in infant formula that does not raise public health concerns. In large part, this is because of gaps in our scientific knowledge.
This is archived on various blogs and the nowpublic site.
The FDA arranged testing on rats and came up with a figure for Tolerable Daily Intake of 0.63 mg/kg bw/d (milligrams/kg body weight/day). A 10-fold safety tolerance has been applied for infants, giving a TDI of 0.063, which, for a 3kg infant, equates to:
0.063 mg/kg-bw/d x 3 kg/infant = 0.189 mg melamine/infant/day.The calculation continues:
To estimate the level of melamine that does not raise public health concerns, FDA used a worst case exposure scenario in which all of an infant’s total daily dietary intake (typically 0.15 kg powdered infant formula) is contaminated with melamine. The previously determined (see above) total amount of melamine/infant/day:
0.189 mg/infant/day divided by 0.15 kg of food = the food contamination level that would provide this amount of melamine to a 3 kg infant per day. Thus, 0.189 mg melamine divided by 0.15 kg of food = 1.26 mg melamine/kg food.
Therefore, if 100% of the diet were contaminated at a level of 1.26 ppm of melamine, an infant’s daily intake would equal 0.063 mg/kg bw/d. This value of 1.26 ppm is rounded down to 1.0 ppm melamine to provide an additional margin of safety.
The FDA also arranged testing of US-manufactured and found contamination with melamine, but below this 1.0 ppm level.
This information was not released, however, and it took a Freedom of Information request from the Associated Press. They report on the manufacturers whose formula is contaminated with melamine and/or cyanuric acid, which is often found together and has been ascribed the same safety limit. See:
Mead Johnson's Infant Formula Powder, Enfamil LIPIL with Iron found melamine at levels of 0.137 and 0.14 parts per million. Three tests of Nestle's Good Start Supreme Infant Formula with Iron detected an average of 0.247 parts per million of cyanuric acid.
So the FDA does not include these products on its list of those to avoid. It does, however, continue to list "infant formula manufactured in China" as a blanket prohibition. See:
Melamine has also been found in Nestlé formula in Saudi Arabia, though the levels are not given.
Levels in Sanlu/Fonterra formula that caused the problems in China were 1,000 times higher than those found in these US formula, but at the time Nestlé boasted that no melamine had been found in Nestlé products - though this was not true as a Nestlé whole milk was on the contaminated list. See:
Nestlé hasn't commented on its website on the latest cases where melamine has been found in its products.
CNN has a response from a US trade body. See:
A spokeswoman for the Atlanta, Georgia-based International Formula Council, a trade group, said she had not seen the data, but was encouraged that the quantity found was below levels deemed safe in infants by the governments of China, Malaysia, the Philippines, Hong Kong, Canada and New Zealand.
"Apparently these trace levels can be found in lots of food," said spokeswoman Mardi Mountford.
So to summarise, the levels found in Nestlé and Mead Johnson formula is about one thousandth of the level that led to thousands of babies being hospitalized in China and at least four deaths. However, little is known about the effects of lower-level contamination. Evidence used for the FDA analysis is based on preliminary studies on rats.
It is in the industry's interest to downplay the risks, because it could affect their profits. And we may not actually know for some years what the impact may be.
With other medicines (and strictly speaking, formula is a nutritional medicine intended for specific cases of intervention) successful tests on animals and even human trials do not detect all problems. It is not unusual for drugs to be recalled after problems are detected when they are used in far larger populations.
However, any sickness that may be caused by even low levels of melamine in formula may possibly be difficult to detect given that due to the shortcomings of formula, compared to the biological norm of breastmilk, formula-fed infants are more likely to suffer short and long-term illness in any case.
We call for a precautionary principle to be followed and known toxins be excluded from foodstuffs, particularly those for infants.