CSN EN 16120+A2 This European Standard specifies safety requirements and test methods for chair mounted seats intended to be positioned on an adult chair to raise the sitting position of a child able to sit unaided up to an age of 36 months or a maximum weight of 15 kg. This European Standard does not apply to cushions, pads and to products only aimed at restraining the child on a chair without raising the child's sitting position. Original English text of CSN EN Standard. The price of the Standard included all amendments and correcturs.