The explosive and propellantmanufacturing units of the Ordnance Factory Board (OFB) have started making hand sanitisers, joining the battle to combat the Covid-19 outbreak, an official said here on Friday.The state-owned HLL Healthcare has placed an order for 13,000 litres of sanitiser with OFB, which functions under the Defence Ministry, the official said.Factories have started manufacturing sanitisers to meet the rising demand, in the wake of the outbreak, the OFB official said.The first consignment of 100-litre sanitiser, made by Heavy Explosives Factory, Pune, has been delivered to Ordnance Factory, Ambernath, near Mumbai, for one of its quarantine facilities, he added.