Toxicity of Melamine

[greenvet-hanoi]

Toxicity of Melamine.


Melamine is an organic base with the chemical formula C3H6N6, with the IUPAC name 1,3,5-triazine-2,4,6-triamine. It is only slightly soluble in water.
Melamine is a trimer of cyanamide. Like cyanamide, it is 66% nitrogen (by mass) and provides fire retardant properties to resin formulas by releasing nitrogen when burned or charred. Dicyandiamide (or cyanoguanidine), the dimer of cyanamide, is also used as a fire retardant.
Melamine is a metabolite of cyromazine, a pesticide. It is formed in the body of mammals who have ingested cyromazine.[2] It was also reported that cyromazine is converted to melamine in plants.[3][4]

Melamine by itself is nontoxic in low doses, but when combined with cyanuric acid it can cause fatal kidney stones.[15]

[edit] Toxicity


[edit] Acute toxicity

Melamine is reported to have an oral LD50 of >3000 mg/kg based on rat data. It is also an irritant when inhaled or in contact with the skin or eyes. The reported dermal LD50 is >1000 mg/kg for rabbits.[16] In a 1945 study, large doses of melamine were given orally to rats, rabbits and dogs with "no significant toxic effects" observed.[17]
A study by USSR researchers in the 1980s suggested melamine cyanurate (a salt formed between melamine and cyanuric acid, commonly used as a fire retardant[18]) could be more toxic than either melamine or cyanuric acid alone.[19] For rats and mice, the reported LD50 for melamine cyanurate was 4.1 g/kg (given inside the stomach) and 3.5 g/kg (via inhalation), compared to 6.0 and 4.3 g/kg for melamine and 7.7 and 3.4 g/kg for cyanuric acid, respectively.
A toxicology study conducted after recalls of contaminated pet food concluded that the combination of melamine and cyanuric acid in diet does lead to acute renal failure in cats.[20]

[edit] Chronic toxicity

Ingestion of melamine may lead to reproductive damage, or bladder or kidney stones, which can lead to bladder cancer.[16][21][22][23][24]
A study in 1953 reported that dogs fed 3% melamine for a year had the following changes in their urine: (1) reduced specific gravity, (2) increased output, (3) melamine crystalluria, and (4) protein and occult blood.[25]
Wilson Rumbeiha, an associate professor in Michigan State University’s Diagnostic Center for Population and Animal Health, commenting on results from a survey commissioned by the American Association of Veterinary Laboratory Diagnosticians and designed and implemented by MSU toxicologists presented at the AAVLD's October 2007 meeting, said: "Unfortunately, these melamine cyanurate crystals don’t dissolve easily. They go away slowly, if at all, so there is the potential for chronic toxicity.”[26][27][28]

[edit] Incidents involving combination of melamine and cyanuric acid


[edit] 2007 pet food recalls

Further information: 2007 pet food recalls In 2007 a pet food recall was initiated by Menu Foods and other pet food manufacturers who had found their products had been contaminated and caused serious illnesses or deaths in some of the animals that had eaten them.[29][30][31] On 30 March 2007, the US Food and Drug Administration reported finding white granular melamine in the pet food, in samples of white granular wheat gluten imported from a single source in China, Xuzhou Anying Biologic Technology[32] as well as in crystalline form in the kidneys and in urine of affected animals.[33] Further vegetable protein imported from China was later implicated. See Chinese protein export contamination.
The practice of adding "melamine scrap" to animal feed is reported to be widespread in China in order to give the appearance of increased protein content in animal feed.[34]


From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Melamine

 

[topaze]

petfood

Thanks for your post and explanation about melamine, which is a product I think is much more widely spread than we can think.
It can exist in any kind of food material, like milk base products (whey powder, milk replacers...) as well as some agriculture raw material (rice protein concentrate, brans, raw materials that are used in petfood...).
Unscrupoulous chinese suppliers add it into thin grinded powder product or liquids, because it is difficult to detect.
So avoid buying any product from chinese origin, and be careful when you purchase food produced in Asia, they can easily contain contaminated chinese raw materials.
While waiting for control measures to be much more efficient then they are, focus on feeds from US or EU origin who are much more controlled.

 

[greenvet-hanoi]

Plastic 'n gravy: groovy Fido feed?

Plastic 'n gravy: groovy Fido feed?

In March, 2007, the largest pet-food recall in U.S. history started after pet food containing the chemical melamine started killing cats and dogs. A reported 60 million containers of pet food, sold under scores of brand names, were contaminated with a compound normally used to make plastic and fertilizer.

Earlier this year, a massive contamination of pet food with melamine killed thousands of cats. The contaminant, melamine, is normally used in plastic and fertilizer. Fortunately, these puppies didn't get the tainted food. ©S.V. Medaris

All had been made by the Canadian firm Menu Foods, which had blended Chinese wheat gluten contaminated with melamine into its many products.
The estimates of pet deaths ranged past 5,000, but no authoritative death toll has yet been announced.
Melamine is used to coat particle board with an attractive, impervious coating. Melamine also fools protein detectors, which explains its appearance in many Chinese food ingredients, including soy protein and wheat gluten. Sadly, it destroys kidneys, and mammals die.
Food is not supposed to contain melamine, but on April 30, The New York Times reported that manufacturers of various foods -- for humans and animals -- routinely bought it anyway (see #8 in the bibliography). Why? Because the chemical is cheap, and the nitrogen it contains can fool protein tests:
"... two animal feed producers explained in great detail how they purchase low-grade wheat, corn, soybean or other proteins and then mix in small portions of nitrogen-rich melamine scrap, whose chemical properties help the feed register an inflated protein level. 'People use melamine scrap to boost nitrogen levels for the tests,' said the manager of the animal feed factory. 'If you add it in small quantities, it won't hurt the animals.'"

Source : http://images.google.com.vn/imgres?...firefox-a&rls=org.mozilla:en-US:official&sa=N

 

[topaze]

Food imports: How safe?
POSTED 12 JULY 2007

Poisons in food, medicines: Will anything change?
How will the accelerating concern about the safety of Chinese products play out as China's exports continue growing past the $1 trillion mark? So far, China has produced a curious recipe of reactions to the reports of dangerous foods and medicines:

A splash of "what-me-worry?" in the government's absurd assurance that all its exports were "guaranteed" (see #9 in the bibliography);

A dash of regulation: In June, China reported 23,000 violations at food plants and shuttered 180 factories;

A teaspoonful of frontier justice: On July 10, China executed the former director of food and medicine regulation; and

And a sprinkle of defiance: In late June, China impounded two U.S. food shipments, citing high levels of mold and bacteria. (Nine months after deadly bacteria was found on California spinach, Americans might seem in a poor position to caterwaul about food safety, but the E. coli contamination was accidental, whereas in the incidents we are discussing, multiple Chinese malefactors deliberately substituted cheap, toxic ingredients for safe ones.)

People sit around at restaurant, meat hangs on hooks on wall behind them
The safety of China's food is not only an export problem: Who knows what is in the food on this table? Who knows what went into that meat hanging in the background?

Changing course
With so much money at stake, China finally seems to be substituting problem-solving for stonewalling. On June 27, the International Herald Tribune reported (see #10 in the bibliography) on the latest crackdown:

"Regulators said 33,000 law enforcement officials had combed the nation and turned up illegal food-making dens, counterfeit bottled water, fake soy sauce, banned food additives and illegal meat processing plants. ... China Daily, the country's English-language newspaper, said Wednesday that industrial chemicals, including dyes, mineral oils, paraffin wax, formaldehyde and malachite green, had been found in the production of candy, pickles, biscuits, and seafood."

Ian Coxhead, who studies economic development, trade and agriculture in Southeast Asia at the University of Wisconsin-Madison, says the Chinese government has reacted quickly and publicly because "It understands very well the cost to all of high-profile violations by some. Sending US inspectors to police thousands of production processes in tens of thousands of Chinese factories is expensive and impractical. Better that China's trading partners -- all of them -- apply their own health and safety regulations, and give wide publicity to violations when discovered, in the hope that these actions will create disincentives for cheating firms, and stimulate moves to strengthen the institutions of governance and oversight of the market."

 

[catsamac]

It's reason that four babies have died, some animal and more than 53,000 children have so far been made ill by drinking contaminated powder milk in China."It's a tragedy for the Chinese food industry and a big lesson for us as it ruined the time-honoured brand," he was quoted by the Shanghai Daily as saying. (BBC)

Some people is more malicious than devil!

 

[Phu Dung]

Melamine causing renal failure

Chinese protein export contamination

Chinese protein export contamination was first identified after the wide recall of many brands of cat and dog food starting in March 2007 (the 2007 pet food recalls), and eventually involved the human food supply. The recalls in North America, Europe and South Africa came in response to reports of renal failure in pets. Initially the recalls were associated with the consumption of mostly wet pet foods made with wheat gluten from a single Chinese company. In the following weeks, several other companies who received the contaminated wheat gluten also voluntarily recalled dozens of pet food brands. One month after the initial recall, contaminated rice protein from a different source in China was also identified as being associated with kidney failure in pets in the United States, while contaminated corn gluten was associated with kidney failure with pets in South Africa.

The Chinese government was initially slow to respond. Both government officials and manufacturers went so far as to deny that vegetable protein was even exported from China and refused for weeks to allow foreign food safety investigators to enter the country. Ultimately, the Chinese government acknowledged that contamination had occurred and arrested the managers of two protein manufacturers identified so far and took other measures to improve food safety and product quality.

The first and most easily identified contaminant in the vegetable protein is melamine. However, melamine is not considered to be especially dangerous to animals or humans, and so investigators have continued to examine the role of other contaminants found to be present in the proteins, including cyanuric acid. Current research has focused on the combination of melamine and cyanuric acid in causing renal failure. Reports that cyanuric acid may be an independently and potentially widely-used adulterant in China have heightened concerns for both pet and human health.

Both the wheat gluten and rice protein concentrate were found to actually be wheat flour, which contains wheat gluten as a component and is less expensive than separated gluten. Melamine and cyanuric acid were most likely added to fraudulently increase the apparent protein content of the flour to allow them to pass as concentrated vegetable proteins.

Reports of widespread adulteration of Chinese animal feed with melamine have raised the issue of melamine contamination in the human food supply both in China and abroad. On 27 April US FDA subjected all vegetable proteins imported from China, intended for human or animal consumption, to detention without physical examination, including: Wheat Gluten, Rice Gluten, Rice Protein, Rice Protein Concentrate, Corn Gluten, Corn Gluten Meal, Corn By-Products, Soy Protein, Soy Gluten, Proteins (includes amino acids and protein hydrosylates), and Mung Bean Protein. In a teleconference with reporters on 1 May, officials from the FDA and U.S. Department of Agriculture said that between 2.5 and 3 million people in the United States had consumed chickens that had consumed feed containing contaminated vegetable protein from China. Reports that melamine has been added as a binder in animal feed manufactured in North America also raise the possibility that harmful melamine contamination might not be limited to China.

There has been widespread public outrage and calls for government regulation of pet foods, which had previously been self-regulated by pet food manufacturers. The United States Senate held an oversight hearing on the matter by 12 April. [10] The economic impact on the pet food market has been extensive, with Menu Foods losing roughly $30 million alone from the recall.

As of 7 May, United States food safety officials stated: "There is very low risk to human health from consuming meat from hogs and chickens known to have been fed animal feed supplemented with pet food scraps that contained melamine and melamine-related compounds".

In September 2008, Sanlu Group had to recall baby milk due to contamination with melamine. 4 babies died and over 6,000 were made ill.

From Wikipedia

 

[Kelvin Vu]

Following "US TODAY" - Melamine in pet food may not be accidental
A nitrogen-rich chemical used to make plastic and sometimes as a fertilizer may have been deliberately added to an ingredient in pet food that has sickened and killed cats and dogs across the country, public and private officials say. A leading theory is that it was added to fake higher protein levels.
Melamine has been found in wheat gluten, rice protein concentrate and, in South Africa, corn gluten, all imported from China, and all meant for use in pet food, the Food and Drug Administration confirmed Thursday.
It adds to the theory when you see other products that are labeled as protein supplements, in this case rice protein, and in South Africa corn gluten and in the previous case wheat gluten," said Stephen Sundlof, FDA chief veterinarian. "That melamine was found in all three of those, it would certainly lend credibility to the theory that this was intentional."

How the melamine got there is "not something we're going to be able to determine until we actually investigate the plants in China," he said.

The FDA has not yet been able to get letters of invitation from the Chinese government that would allow its inspectors to enter the country, he said.

 

[Kelvin Vu]

I think, the human desire for profit but accidentally breaks safety barriers on health.It was accidentally killed thousands of people innocence. This considerable frustration - Hopefully people will hand them for a world peace - healthy

Kelvin Vu

 

[topaze]

I think it is important to notice that the problem with US pet food was in 2007. According to you was there any new case of melamine contaminated pet food in the US or Europe since that time?

 

[Kelvin Vu]

In my case known infection Melamine in pet food has not confirmed in Vietnam. It is possible we will take a long time to find a solution. Yea - I think so. How 'bout your idea ? topaze

 

[topaze]

I do not know. I just know there is no pet food produced in Vietnam. It is mainly imported from Thailand (Pedigree and CP) with certainly a lot of raw material coming from China as it is nearby and from France (Royal Canin). Maybe there are some other brand that you know in VN?

 

[Kelvin Vu]

Yes, most of the raw materials are imported from China. Don't know containing Melamine is not in ? !
Too human desire to forget that benefits all hazards. Is shame for those who caused this