What’s the difference between 4586 and 3661?

4586 is a more comprehensive standard. It includes four different methods of testing, depending on the intended usage of the floor area. It also includes a list of recommended minimum slip requirements for different locations (HB197). Under 3661 every potentially wet access route requires at least a 0.4 pass. 4586 has specific recommendations, for example, entrance lobbies require less slip resistance than swimming pool surrounds.