Melamine

Field studies

Administrative data

Endpoint:

field studies

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented publication. No GLP.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Basal diets containing 2 mg melamine/kg or 100 mg melamine/kg were fed to groups of pigs, calfs, cows, chickens, sheeps, ducks or trouts for 40 to 60 days. Deposition of melamine in animal tissues and products was determined analytically.

GLP compliance:

not specified

Type of measurement:

Melamine concentrations were analyzed in muscle and kidneys of various animals. Where appropriate also eggs and milk was analyzed.
Method of analysis: Samples were prepared for liquid chromatography-tandem mass spectrometry ( LC-MS/MS). An internal standard [15N3]-melamine was added.

Media:

Animal tissues.

Test material

Test material information

Constituent 1

Reference substance name:

Melamine

EC Number:

203-615-4

EC Name:

Melamine

Cas Number:

108-78-1

Molecular formula:

C3H6N6

IUPAC Name:

1,3,5-triazine-2,4,6-triamine

Test material form:

other: solid

Details on test material:

Purity: 99.4 %Supplier: Sigma Aldrich Shanghai

Results and discussion

Any other information on results incl. tables

Accumulation of melamine in edible tissues of animals:

After feeding 100 mg melamine/kg diet, the highest melamine residues in animal kidney ranged from 95 to 4483 µg/kg, and melamine residues in animal muscles ranged from 59 to 1864 µg/kg. See Figure A of the attachment. Melamine residues in poultry were higher than those in pigs and ruminant animals. The highest levels of melamine in hen eggs, duck eggs and milk were 2366, 1720 and 487 µg/kg respectively. For rainbow trout, the maximum melamine concentrations in the kidney and muscle were 14.3 and 3.6 mg/kg, respectively, which are much higher than the 51 to 237 µg/kg melamine at concentrations detected in marker-ready fish.

Deposition of melamine in animal tissues at a melamine concentration of 2 mg/kg in diets is shown in Figure B of the attachment. Overall, the highest melamine concentrations tested were 17-122 µg/kg in the kidney and 14-86 µg/kg in muscle tissues. When Holstein dairy cows, hy-line layers and Jinding laying ducks consumed diets contained 2 mg melamine per kg, the highest melamine concentration in milk, hen eggs and duck eggs was determined at a level of 40, 95 and 43 µg/kg, respectively. At this level of melamine contamination in diets, the deposition of melamine in animal tissues and products was lower than the upper limit of melamine in infant milk powders (1 mg/kg) allowed in the USA.

 

Elimination of melamine in animal tissues and products; after switching to melamine-free diets:

The results indicated that the depletion of melamine to an undetectable level from animals other than fish was completed in 96 h (4 days) after animals consumed melamine­free feedstuffs. Conversely, the elimination time of melamine in fish was longer: 14 and 5 days in the kidney and muscle, respectively.

Applicant's summary and conclusion

Conclusions:

Melamine in the diet was fed to the species investigated (pigs, calfs, cows, chickens, sheeps, ducks or trouts) for 40 to 60 days. Melamine was taken up in edible tissues, reaching a maximum concentration of 4.5 mg/kg in kidney of chicken after feeding 100 mg melamine/kg diet. After feeding the maximum background level of melamine observed in crops of ca. 2 mg/kg, each of the investigated tissue level was well below 1 mg/kg tissue.
Switching to a standard diet for 4 days depletes the melamine tissue levels to undetectable concentrations, except for fish. For fish the elimination time was up to 14 days.

Executive summary:

Melamine in the diet was fed to the species investigated (pigs, calfs, cows, chickens, sheeps, ducks or trouts) for 40 to 60 days. Melamine was taken up in edible tissues, reaching a maximum concentration of 4.5 mg/kg in kidney of chicken after feeding 100 mg melamine/kg diet. After feeding the maximum background level of melamine observed in crops of ca. 2 mg/kg, each of the investigated tissue level was well below 1 mg/kg tissue.

Switching to a standard diet for 4 days depletes the melamine tissue levels to undetectable concentrations, except for fish. For fish the elimination time was up to 14 days.