hello mark,
Yup BS EN131 is the standard for trade ladders (previously BS2037 Class 2) which wont invalidate ur insurance.
The domestic standard is currently BS 2037 Class 3, so make sure you avoid them.
I orded some new ladders yesterday from
www.ladders999.co.uk titans is a good brand, thats what scrimcity and sells , but they are slightly cheaper at ladders999 for the same titan ladders.
sam