Permitted Work - 16 exactly

I know the rule with ESA Permitted Work (amongst others) is: ''work for less than 16 hours each week''.

However there is a role I applied for that is exactly 16 hours.

I'm struggling to understand whether the 16 hours is a 'limit', or whether exactly 16 hours would be too much?

Any guidance welcome, as always the 'fine detail' in the Gov sites is seems missing or baffling.