Wednesday, January 18, 2012 | American Chemistry Council Inc.
The European Food Safety Authority (EFSA) recently released one of its studies showing that current dietary exposure to tetrabromobisphenol A, a widely used flame retardant commonly called TBBPA, does not raise a health concern.
EFSA found no TBBPA in the 344 food samples that were submitted for analysis. So EFSA used a scientific model based on worst-case assumptions, along with rat and mice studies, to draw its conclusions. The study concludes that it is unlikely that combined exposure to TBBPA through food and household dust would result in a health concern. Similarly, exposure to infants through human milk consumption does not raise a health concern.
TBBPA is the largest volume brominated flame retardant in the world, with applications in a variety of plastics, printed circuit boards and electronic equipment. EFSA’s findings should reassure the public that flame retardants, like TBBPA, can be used safely to help protect life and property.
Examined studies on food samples (all from the “fish and other seafood” food group) that looked for TBBPA. Seventy percent of the samples were from Norway and 30 percent from Spain. No TBBPA was found in any of the samples. So a worst case estimate was made by assuming that the levels were actually equal to an upper bound estimate based on the premise that the Limit of Quantitative data represents the mean value of TBBPA.
Considered analytical data from a variety of studies to detect TBBPA.
Considered data on TBBPA measured in human milk (0.06 -37.3 ng/g fat) and assumed above average daily consumption.
EFSA used the Margin of Exposure (MOE) approach, whereby upper bound human exposure estimates are compared with the dose in animal toxicology studies that showed no adverse effects. The margin between the human exposure level and the no observable effect level of the toxicology study is a measure of the relative safety of the exposure. They consider a MOE of 100 to 1000 as acceptable, meaning that there is reasonable certainty of no harm if the human exposure is 100-1000 times less than the no adverse effect level in animals.
EFSA’s Key Findings
Dietary exposure of fish and other seafood
The study comparing the “upper bound” dietary exposure estimate of 2.6 ng/kg body weight per day for the specific group of adult high-fish consumers resulted in a MOE of 6,000,000. The MOE is sufficiently large enough that EFSA concluded that the current dietary exposure to TBBPA does not raise a health concern.
Human milk (breast-fed infants with average or high human milk intake)
Consumption of human milk intake is associated with MOEs ranging from 10,000 to 10,000,000. Because of these large MOEs, EFSA concluded that exposure of TBBPA via human milk does not raise a health concern.
Dust (in homes, classrooms and cars)
EFSA looked at exposure to dust, as it is a potentially important route for exposure for children.
EFSA concluded that the typical exposure scenario (1.2 ng/kg) is associated with an MOE of about 13,000,000. This MOE also indicates that exposure of children to TBBPA from dust does not raise a health concern.
Based on the large MOEs derived for both dietary exposure and exposure through dust, the EFSA concluded that even combined exposure from both food and dust are unlikely to result in a health concern for humans. Similarly, exposure of infants through human milk consumption does not raise a health concern.