This hand soap contains antibacterials that can effectively kill 99% of bacteria.

antibacterials 是 antibacterial 的复数形式。antibacterial 由前缀 anti-（表示"对抗"）和 bacterial（细菌的）组成，字面意思是"对抗细菌的"，指"抗菌物质"或"抗菌成分"。