The assessment relies on certain assumptions and calculations: That melamine is metabolically inactive and is eliminated as melamine; that three melamine analogues share an equal potency; and that melamine is unlikely to accumulate over time in edible tissues of animals. FDA calculated its exposure estimates, including a substantial safety factor on the analytical limit of detection for melamine of 50 parts per billion (ppb), and then doubled it to account for the possible presence of one of the three analogues which is not measured by the test (cyanuric acid). FDA calculated daily intake estimates using three different eating plans:
1. Consumed as catfish, chicken, eggs and pork (100ppb) = a mean of seven micrograms per person per day; and 14 micrograms per person per day at the 90th percentile.
2. Consumed as chicken, pork and by-products (100ppb) = a mean of two micrograms per person per day; and six micrograms per person per day at the 90th percentile.
3. Consumed in all solid food (100ppb) = 150 micrograms per person per day.
No Observable effect level of 63mg/kg/day times a safety factor of 100 yielding a Tolerable Daily Intake of 0.63.
The highest exposure(s) estimated using the FDA’s assumptions and calculations was found to be as much as 200 times below the Tolerable Daily Intake.
FDA concluded that the consumption of meat products from animals whose feed was contaminated with melamine is “unlikely to pose a human health risk.”
While noting that the food products contaminated with any level of melamine could be considered adulterated under its statutes, FSIS states, “(b)ased on the results of the measured melamine concentrations in pork and poultry tissue samples from animals exposed to adulterated feed, together with the findings of the interim safety/risk assessment, FSIS had determined that it is able to find that pork and poultry products from animals that have consumed feed that contain pet food scraps contaminated with melamine and melamine-related compounds are ‘not adulterated’ and thus eligible to receive the mark of inspection under the FMIA and PPIA.”
Imported Food SafetyPresident Bush has signed an Executive Order “Establishing An Interagency Working Group on Import Safety.” The 13 member group, plus employees and staff, will be known as the “Working Group” and is charged with “(identifying) actions and appropriate steps...within existing resources, to promote the safety of imported products...”
Means at the disposal of the Working Group include: reviewing current procedures to ensure the safety of imported products; identifying means to enhance the safety of imported products; and using all available resources to safeguard the imported food supply. Recommendations are due to the president within 60 days, unless it is determined that additional time is necessary.
Two bills were introduced with the stated goal of improving the safety of imported food: the Assured Food Safety Act of 2007 (H.R. 2997) and the Imported Food Security Act of 2007 (S. 1776).
H.R. 2997, the Assured Food Safety Act of 2007 (foods under the jurisdiction of either the FDA or the USDA), establishes a program for requiring all foods imported into the U.S. be accompanied by “a certificate of assured safety” issued by the government from which the import originated. The bill also requires that within one year a study be completed to assess “the minimum amount of inspection necessary to assure consumers of a safe food supply.” The program will be paid for by user fees.
S. 1776, the Imported Food Security Act of 2007 (foods under FDA jurisdiction only), would provide that funds collected through a user fee system be used for developing techniques for food safety inspections of imported food, requiring that FDA establish a certification system for foreign governments and establishments seeking to import food to the U.S. that is comparable to U.S. standards for food safety, labeling and inspection.
Additional food safety import legislation is expected from Rep. John Dingell (D-Mich.).
The risk assessment on melamine seeks comment from the public. The interim assessment is available at http://www.cfsan.fda.gov/~dms/melamra.html.