mercury slip rings used to replace copper slip rings in the uk

[andy1231]

Has anyone replace copper slip rings with mercury ones. At the present i have a heated roller with 5 copper slip rings on, the first 3 rings are for 3 phase heater inside the rollers, the last 2 are for the thermocouple temperature reader..
I have never used mercury slip rings before and are concerned with legal and law relating to the use of

any help or info would be appreciated