Check EASA PCDS Memorandum issued 8 Dec 2014
Please find herewith enclosed the link to the document they released on 8th December
Certification Memoranda | EASA (click on the first doc on the left hand side).
Bottom line anything used to secure someone who is loose in the cabin must meet EN PPE Directives and be submitted as a minor change to the aircrafts airworthiness.