The Enforcement Rules of the Prison Act Article 42

In requiring prisoners to take showers, shave and cut hairs in accordance with Article 53 of the Act, Prisons shall follow the principle of maintaining public hygiene and personal health.
中文原文 監獄行刑法施行細則第42條
監獄依本法第五十三條要求受刑人沐浴及理剃鬚髮,以維持公共衛生或個人健康為原則。

English translation for reference only; the Chinese text prevails. Not legal advice.