Aspects relate to monitorable plasma torch device components and in particular to monitoring and predictive maintenance of one or more such monitorable plasma torch device components. One aspect provides a monitorable plasma torch device component, the component comprising: a component body and a sacrificial component located in an erosion zone of the component body. The sacrificial component comprises material which differs from the plasma torch device component body and which, on exposure to a plasma torch in a plasma torch device, generates electromagnetic radiation distinct from that of the plasma torch device component body. The distinct electromagnetic radiation generated is indicative of erosion of the monitorable plasma torch device component in the erosion zone. Such a monitorable plasma torch device component can facilitate effective component monitoring which allows for ameliorative action to be taken in the event that degradation of the device component is detected.