According to European legislation, face masks are not suitable for return due to health protection and hygiene reasons.
DIRECTIVE 2011/83/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL
of 25 October 2011 on consumer rights, amending Council Directive 93/13/EEC and Directive 1999/44/EC of the European Parliament and of the Council and repealing Council Directive 85/577/EEC and Directive 97/7/EC of the European Parliament and of the Council
Exceptions from the right of withdrawal
Member States shall not provide for the right of withdrawal set out in Articles 9 to 15 in respect of distance and off-premises contracts as regards the following:
(e) the supply of sealed goods which are not suitable for return due to health protection or hygiene reasons and were unsealed after delivery;