The second means that there is a chance that you will not take work on holiday at all (and consequently the work would not be done).
In the second, we would say "there is a risk of not taking work on holiday..."
I wouldn't use "holidays". In AmE that means a festive/celebratory period (Christmas, Thanksgiving etc) and in BrE it would mean more than one holiday (ie vacation). A holiday in the UK is when you travel away from your home alone or with friends or family to have some fun in your own country or abroad. I would never "take work on holiday" - I'm not paid enough to do that!!
- For Teachers