A melamine scandal broke out in March 2007 when the substance was found to have caused the death of many pets in various parts of the world, including South Africa. Melamine had been illegally and fraudulently added to imported Chinese protein that was being used in the manufacture of pet food – it resulted in possibly the biggest ever pet food recall.
An even bigger and much more serious scare erupted in September 2008 when melamine was found to be responsible for the hospitalization and / or treatment of tens of thousands of Chinese children suffering from kidney stones and related problems. Several children died of kidney failure and the number that ultimately received attention may have reached 100,000. Once again, melamine had been illegally and fraudulently added to a food product, on this occasion milk for human consumption through which it found its way into infant formulas and a wide range of products that have milk or milk powder as an ingredient. Ultimately, many hundreds of different products were affected. Fortunately, the adulteration problem remained confined to China and Chinese products which facilitated safety checks, market withdrawals and international recalls.
Over thirty dairy companies were found to be involved in the scam which was reported to have affected production between March and August 2008. Some 5,000 inspectors were deployed in the dairy industry to monitor the situation, take samples and conduct tests. By the end of September, 27 individuals had been arrested in connection with the scandal and it was found that about 12% of the milk powder products sampled contained melamine.
The US Food and Drug Administration (FDA) opened offices in three Chinese cities in order to assess and keep abreast of the situation. The World Health Organisation (WHO) set tolerable daily intake (TDI) levels for melamine ( 0,2 mg/kg body weight) but no “safe” level was ever set due to uncertainty about the specific effects that it may have on the human body, especially infants. The TDI is basically the amount that an adult can consume on a daily basis over a lifetime without an appreciable risk to health. One infant formula tested in China was found to contain 2, 500mg / kg of melamine! By February 2009 the number of reported contamination events had reached a very low level.
Melamine in South Africa
Although no Chinese milk or milk powders had been legally imported into South Africa since about 2003, melamine had found its way onto local shelves via imported goods from that country that contained contaminated milk as an ingredient. The Dept of Health ordered the removal from the market of any Chinese foodstuffs containing milk and related ingredients including infant formulas, sweets, toffees, chocolates, biscuits, etc., and set about monitoring all baby formulas in South Africa. The Dairy Standards Agency and the SA Milk Producer’s Organisation alerted members and producers to the scare and specifications of all incoming materials was rigorously checked.
Low levels of melamine appeared in local milk for a short time as a result of contaminated animal feed that had been fed to cows. In January 2009 the Department of Health set maximum melamine levels for all foodstuffs at 2,5 mg/kg and, for infant formulas intended for children under 36 months of age, at 1mg / kg. Foodstuffs containing higher levels were deemed to be contaminated, impure or adulterated. By March 2009, about one year after the adulteration of milk had begun in China, the melamine issue in South Africa had been fully contained. No cases of sickness or death due to the ingestion of melamine are known to have occurred in South Africa However, sampling and testing by the Dept of Health and a network of co-operating organizations continues to the present. A number of companies also instituted monitoring mechanisms to mitigate the risk for contamination, by frequently checking the raw /source ingredients that are traditionally used in milk and other products.
What is Melamine?
Melamine is a mildly toxic, odourless, white crystalline powder that melts at 347 Degrees Centigrade. It is used industrially to make hard wearing, heat resistant counter tops such as are used in kitchens and canteens. It is also used in the manufacture of plastic dishware, bottle caps, whiteboards, coatings, adhesives and insulators.
Why is Melamine Found in Food?
The addition of melamine to foodstuffs and feed is not approved by the World Health Organisation nor by any national authority anywhere in the world.
Melamine is illegally added to food and food ingredients in order to give the impression that the protein content of the food is higher than it really is. In cases where the amount of protein in a product is important, higher protein levels will fetch higher prices. For example, in the case of wheat gluten used for animal feed, the product may be diluted with cheaper low protein materials and then “boosted” with melamine. Because normal routine laboratory tests for protein do not distinguish between protein and melamine, the final results are not questioned if they happen to fall within expected values. Relatively small quantities of melamine yield relatively high “protein” values which can make this fraudulent activity quite profitable as long as the perpetrators can escape detection. Detection was probably thought to be unlikely because melamine is not expected to be in food and has never been routinely tested for. In the case of milk adulteration, water may be added and then “boosted” with melamine to yield normal “protein” levels. Unfortunately, when the milk is spray dried the melamine content is concentrated and when used as the basis of an infant formula, often a baby’s only source of food, the concentrated and continuous exposure can lead to kidney failure, kidney stones and death as experienced on a very large scale in China.
Other sources of melamine in foods:
Transfer of melamine from melamine-containing feed to cow’s milk has been reported.
Melamine is used in the production of melamine resins, typically by reaction with formaldehyde. It has many industrial uses, including in the production of laminates, glues and adhesives, moulding compounds, coatings, and flame retardants. Melamine is a minor metabolite of the pesticide cyromazine and is used in some fertilizers. Some approved uses of melamine in the United States are as an indirect food additive as a component of glues and adhesives, and in Europe as a monomer and as an additive in plastics. Consequently, low levels of melamine can migrate into milk and dairy products from food contact material. These levels are typically below 1 mg/ kg1.
What are the Symptoms of Melamine Poisoning?
Irritability, high blood pressure, blood in urine, little urine, signs of kidney infection. Treatment may include fluid infusion, urine alkalinisation, electrolyte and acid-base correction, removal of kidney stones, etc.
In what Products has Melamine been Found?
Milk, milk powder, baby food and formula, yoghurt, biscuits, sweets, chocolates, toffees, tea and coffee products, instant coffee, chicken, eggs, pet food, animal feed, fish food, raising agents, etc.
- Fischer, W.J., Schilter, B., Tritscher, A.M., Stadler, R.H., 2015. Contaminants of Milk and Dairy Products: Contamination Resulting from Farm and Dairy Practices. Reference Module in Food Sciences. Elsevier, pp. 1-13. doi:http://dx.doi.org/10.1016/B978-0-08-100596-5.00698-3
Updated for FACS by ABe (2016)