Mineral insulated (Magnesium Oxide insulant) cable was first designed by Swiss Engineer Francois Borel in 1896.

The design was adopted by Pyrotenax France in 1932
and was acquired by BICC in 1947.

First plant built on the River Tyne manufactured MI cable for war ships - anti-mine applications.

In the 1950s it was further developed as a heating and thermocouple cable for the Nuclear Industry.

MI cables are still the only non-ageing fireproof cables and designed to transmit heat from the conductor to sheath.