属水性化学性紫外线吸收剂，危险指数为 3/5(越高越不好)[2]。
[2] 张丽卿，『优质保养品选择策略』，联经出版社，2003/07/10。
Ensulizole是一种紫外线UVB防晒剂，也能吸收很小部分的UVA波段，属于水溶性化学防晒剂，缺点是曝露于阳光下会产生自由基，从而损伤皮肤DNA，严重时有致癌的可能。
About ENSULIZOLE: Known to produce free radicals when exposed to sunlight, leading to damage of DNA, this UVB protector may have the potential to cause cancer.
Source: https://www.ewg.org
添加量少于百分之4是安全的。
The Food and Drug Administration (FDA) reviewed the safety of Phenylbenzimidazole Sulfonic Acid and approved its use as an active ingredient in Over-the-Counter (OTC) sunscreen drug products at concentrations up to 4%.
信息来源
https://cosmeticsinfo.org/ingredient/phenylbenzimidazole-sulfonic-acid