VPROTEQUIP2070 - Protective equipment: Protective boots and helmets for industrial use: What is the difference between a shoe and a boot?
The British Standards Institution has defined a boot as having a minimum leg height of 90mm measured vertically from the insole at the back. The European Standard gave the minimum height of the upper (that is measured vertically from the insole at the back) of 103mm for a size 36 (UK 3) and below, through to a minimum height of the upper of 121 mm for a size 45 (UK 11) and above. Both Standard measurements were accepted for the purposes of the VAT relief. In 2004 the British and European Standard specifications were subsumed within the International Standard.
The zero rate specifically only applies to protective boots for industrial used. Protective shoes are not eligible for the relief.