戊二醇 具有抑菌效果之多元醇，可帮助保湿及渗透，添加量在5%左右，就具有防腐效果，但对于产品开封后之保存无法与真正防腐剂相同。

A synthetic skin-replenishing agent and solvent.

Pentylene Glycol is synthetic humectant used in cosmetics and beauty products that is also secondarily used as a solvent and preservative. It is both water and oil-soluble and can have moisture-binding and antimicrobial properties


http://www.creative-developments.co.uk/papers/Preservatives%20SPC%202000.htm