CrocsUnisex Adult Bistro Work Clog

What would UK size 7.5-8 be for male, and is it slip resistant against oil and grease???

Are these unvented? As in they are fully enclosed at the front and sides? I need them for gardening so need a pair without holes/vents.

What size is a U.K. 5.5

I am a womens size 6 (uk). what size would you recommend? and are they a slim shoe or an extra wide fit? any help would be great thanks