Comparative analysis of bioaccessibility tests for metals and metalloids: Methodological advancements and implications for consumer product safety

Bioaccessibility is crucial in human health risk assessment as it predicts the fraction of metals and metalloids absorbed by the human body. This study compared the modified RIVM method, which includes acid digestion, with the ERU 19899 EN method to assess the oral bioaccessibility of certified reference materials. The modified RIVM method showed higher bioaccessibility, offering more conservative health risk values. Adding a filtration step after centrifugation with a 0.45 μm filter reduced the error in the results from 66.7 % to 19.9 % by removing small particles that were not separated during centrifugation. Dermal bioaccessibility was evaluated using two artificial sweat solutions: one with five amino acids at pH 5.5 and the EN 1811 method at pH 6.5. The pH 5.5 solution leached more metals due to complexation between amino acids and metal ions, increasing solubility. Sebum decreased the leached amount of cationic metals (Cd, Cr, and Pb), as fatty acids can form complexes with metal ions. Therefore, a solution with five amino acids at pH 5.5, without sebum, is suggested for assessing dermal bioaccessibility. Various consumer products, including seven toys, were tested for both oral and dermal bioaccessibility to provide more reliable health risk assessment information. The oral bioaccessibility results of the toys aligned with other studies. The dermal bioaccessibility of the consumer products ranged from 0.001 % to 1.414 %, with the highest Cr concentration measured in a brown watch strap.