What is an appropriate age for children of the opposite sex to go into a change room?

Mr

They just changed the rules in my community at the public swimming pools. They all have a women’s, men’s and family change room. If you have a little boy, he is able to go into the women’s change room until he’s 8 and vis versa. Once he’s 8 you must go into the family change room. Personally I can’t image me taking my 7 year old into a women’s swimming pool change room when there is a family change room available. I think id start utilizing it from a younger age, more like 4/5.

What do you think. What is the appropriate age for this?