This document specifies safety requirements for design, sizing, materials, strength and in-water performance as well as provisions for marking and the information supplied by the manufacturer for swim seats. It also specifies the relevant test methods. This document is not applicable to products covered by EN 13138-1 and EN 13138-2. This document applies only to devices into which the user is placed and which have either inherent buoyancy or can be inflated or a combination of both. It only applies to class A devices intended to introduce the user to the water environment. These devices are only intended for children aged up to 36 months with a body mass less than or equal to 19 kg. It does not apply to class B or class C devices, to pull buoys, lifebuoys, buoyancy aids, lifejackets or aquatic toys.