Is there a chemist in the house?
One thing that has been remarkable about this milk scandal is how everyday, either by real news or rumor, we here are hearing about another Chinese-produced dairy-based product that is being pulled from the shelves somewhere in Asia. Ritz crackers with cheese filling, some Oreo products, and even Cadbury chocolate are some of the most recent foods that have been tested by some government authority because melamine has been detected, sometimes in levels as low as a few parts per million.
This is where I start to get confused. This is where I need a chemist.
Looking at the original test information released by the Chinese government (which are translated into English on this wikipedia site), it is obvious that the Sanlu product's melamine contamination is outrageously high. Many have admitted that they did, in fact, add melamine to milk to boost the apparent protein content of poor quality or even watered-down milk. More products were tested, more found to have some level of melamine content. It seems almost that any product tested has some level of melamine content. I mean, just the other day a New Zealand-produced milk product exported to China was tested here in China and found to have melamine content of 4 ppm. It was also tested in New Zealand, and the Chinese findings were confirmed.
At what point are we talking about intentional melamine addition (as in Sanlu) and melamine migration from handling, processing or packaging? Certainly, no one in the free world would dream of suspecting New Zealand dairy companies of unscrupulously or uncaringly adding melamine to boost their apparent protein content. However, when reading about the levels for which all kinds of products are being pulled from the shelves, some things are being rejected for levels in the double and single digit ppm range.
Correct me if I am wrong, but I have not come across a specific FDA definition of what are "harmless" levels of melamine consumption (though this report from last year seems to say that .63mg per kilogram of body weight is Tolerable Daily Intake), while in this New Zealand article it states that the European Food Safety Authority says that a human can tolerate daily consumption of 0.5 mg per kilogram of body weight. A 20 kilo child, about Myles' size, could safely consume 10 mg per day and not expect to experience adverse affects, they say. If this is true, then I'm really sorry I threw out his one bag of M&M's.
So, at what levels are we to suspect more contamination by chemical migration than unscrupulous dairy companies? Melamine is in a lot of things, especially all kinds of great Williams-Sonoma baking products. As a plastic, melamine is used frequently in brightly colored kitchen products because of its ability to hold color, but it can also be used in all kinds of applications that need to take advantage of its hardness and other properties.
Certainly, Sanlu admitted wrong-doing or, at least, knowledge of wrong-doing (albeit only after the Olympics) and company executives, a city mayor, and local party officials have resigned. Arrests have been made in the case of Sanlu. Are other companies, like Nestle and Mars candy, now victim of overzealous testing? Would we find comparable melamine levels in Dean's milk or even something like Organic Valley in the US as has been detected in other (non-Sanlu) products? If American products were tested, would anyone assume intentional addition, or would it be just be chalked up to chemical migration of some melamine in the processing or handling equipment?
For the sake of full-disclosure, though, we in our family are working on the assumption that any melamine level detected must be bad, because we are that paranoid. As soon as we hear something has been pulled from the shelves somewhere else in Asia, it gets removed from our own shelves.
Update 5:42 pm: Randy read this over, and probably I should have talked it over with him. He may not be a polymer chemist, but he sometimes plays one at work. Melamine is a thermoset, which is usually stable (no free melamine to migrate out of the matrix). However, as he tells me, if for some reason some portion of the melamine does not cross-link, because of an incomplete reaction (due to things like time and temperature) or an amount of melamine in excess of the other reactants in the mix, or a poor mix, or any of a host of reasons, there would definitely be melamine free to leech into other things. I still wonder, though, what would be an expected level from that type of contamination and what level is from a more reprehensible contamination.
This is where I start to get confused. This is where I need a chemist.
Looking at the original test information released by the Chinese government (which are translated into English on this wikipedia site), it is obvious that the Sanlu product's melamine contamination is outrageously high. Many have admitted that they did, in fact, add melamine to milk to boost the apparent protein content of poor quality or even watered-down milk. More products were tested, more found to have some level of melamine content. It seems almost that any product tested has some level of melamine content. I mean, just the other day a New Zealand-produced milk product exported to China was tested here in China and found to have melamine content of 4 ppm. It was also tested in New Zealand, and the Chinese findings were confirmed.
At what point are we talking about intentional melamine addition (as in Sanlu) and melamine migration from handling, processing or packaging? Certainly, no one in the free world would dream of suspecting New Zealand dairy companies of unscrupulously or uncaringly adding melamine to boost their apparent protein content. However, when reading about the levels for which all kinds of products are being pulled from the shelves, some things are being rejected for levels in the double and single digit ppm range.
Correct me if I am wrong, but I have not come across a specific FDA definition of what are "harmless" levels of melamine consumption (though this report from last year seems to say that .63mg per kilogram of body weight is Tolerable Daily Intake), while in this New Zealand article it states that the European Food Safety Authority says that a human can tolerate daily consumption of 0.5 mg per kilogram of body weight. A 20 kilo child, about Myles' size, could safely consume 10 mg per day and not expect to experience adverse affects, they say. If this is true, then I'm really sorry I threw out his one bag of M&M's.
So, at what levels are we to suspect more contamination by chemical migration than unscrupulous dairy companies? Melamine is in a lot of things, especially all kinds of great Williams-Sonoma baking products. As a plastic, melamine is used frequently in brightly colored kitchen products because of its ability to hold color, but it can also be used in all kinds of applications that need to take advantage of its hardness and other properties.
Certainly, Sanlu admitted wrong-doing or, at least, knowledge of wrong-doing (albeit only after the Olympics) and company executives, a city mayor, and local party officials have resigned. Arrests have been made in the case of Sanlu. Are other companies, like Nestle and Mars candy, now victim of overzealous testing? Would we find comparable melamine levels in Dean's milk or even something like Organic Valley in the US as has been detected in other (non-Sanlu) products? If American products were tested, would anyone assume intentional addition, or would it be just be chalked up to chemical migration of some melamine in the processing or handling equipment?
For the sake of full-disclosure, though, we in our family are working on the assumption that any melamine level detected must be bad, because we are that paranoid. As soon as we hear something has been pulled from the shelves somewhere else in Asia, it gets removed from our own shelves.
Update 5:42 pm: Randy read this over, and probably I should have talked it over with him. He may not be a polymer chemist, but he sometimes plays one at work. Melamine is a thermoset, which is usually stable (no free melamine to migrate out of the matrix). However, as he tells me, if for some reason some portion of the melamine does not cross-link, because of an incomplete reaction (due to things like time and temperature) or an amount of melamine in excess of the other reactants in the mix, or a poor mix, or any of a host of reasons, there would definitely be melamine free to leech into other things. I still wonder, though, what would be an expected level from that type of contamination and what level is from a more reprehensible contamination.
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i miss you!
RheaDogg
These days, though, we are just drinking juice and the occassional ginger ale :-)