However, the emphasis on speed of deployment has raised concerns about political interference in the work of the independent safety regulator.

The ban was lifted after the safety regulator accepted analysis from aircraft and engine manufacturers that commercial jets could fly safely where there was some contamination.

The nuclear safety regulator has been accused of turning a blind eye to dozens of serious mistakes at power plants and military bases.

The national proposal would reverse this modern trend and create a single rail safety regulator.

In recent years, there has been a debate among scientists and safety regulators about how harmful these chemicals can be - leading to paraben-free alternatives.