BS 148:2020

This British Standard specifies requirements for recycled oxidation inhibited and uninhibited mineral insulating oils, as delivered, for use in transformers, switchgear and similar electrical equipment in which oil is required as an insulant and/or for heat transfer.

Oils with and without additives are within the scope of this standard.

This standard does not differentiate between methods used to recycle used mineral insulating oil, thus reclaimed or regenerated oil, re-refined oil, dechlorinated oil and reconditioned oil are all considered recycled oil for the purposes of this standard.

This standard does not apply to mineral insulating oils used as impregnates in cables or capacitors, or to hydrocarbon insulating liquids obtained by synthesis.

NOTE Oils conforming to the requirements of this standard, and containing no additives, are considered to be compatible with one another and can be mixed in any proportion. This does not necessarily apply to oils containing additives, and where the user wishes to mix such oils a check should be made to ensure that the mixture conforms to the requirements of this standard.