The Federal Data Protection and Information Commissioner (FDPIC) considers the use of recognition systems that use biometric features in the workplace to be critical, as it means that the employer interferes with the personal rights of its employees.In order for the employer to be allowed to process biometric data of its employees, it requires a justification. Data processing may be justified by law, by overriding public interests or by overriding private interests of the employer. Consent, which is only valid if it is completely voluntary, is in principle not a justification reason, as there is a certain amount of coercion in the employment relationship.
Source: FDPIC – Are working time recording and access controls with biometric data permitted?