Scrap metal cargoes mixed with potentially flammable materials such as batteries and gas bottles pose an increased risk for bulkers, according to maritime insurer Gard.

The Norwegian insurer said it had identified cases in which fires started on vessels because of dangerous material in supposedly inert cargoes, and some have taken days to put out.

Problems include the failure to screen cargoes properly and the growing use of rechargeable lithium-ion batteries found in mobile phones, cars and laptops.