KMB is studying whether to conduct alcohol breath tests on its drivers before work - a practice that bus captains at rival New World First Bus strongly opposed. Under a regulation that New World and subsidiary Citybus introduced on Tuesday, drivers would be fined or even sacked should tests show they had six or more micrograms of alcohol in every 100 millilitres of breath. The legal limit is 22mcg/100ml of breath. The chairman of the Citybus employees' union, Hui Hon-kit, who organised a small protest at the Transport Department yesterday, said the bus management was doing a job that was not theirs. 'Police are already performing random breath tests on the street. Is New World enforcing their own law now? What gives them the right to do that? And how did they arrive at the 6mcg threshold?' He said that according to the company notice, drivers on a first offence would have to pay a HK$500 fine and would receive a written warning. The second time, the penalty is HK$1,000 and a final warning. Drivers exceeding the legal limit would be sacked immediately. A KMB spokeswoman said they were exploring the possibility of a regulation, but had no decision yet. A KMB staff union leader, Keung Ping-yuen, said the company had to consult them if they were to push forward the proposal. 'The limit adopted by Citybus seems a bit too tough: will our drivers take the blame even if they have only had food cooked in alcohol? We need all relevant figures.' A New World spokeswoman said the stringent limit was set to protect the safety of passengers, and it had already taken into account that some foods contained alcohol. The four unions of New World and Citybus were also concerned about a new policy that removed overtime payments for drivers involved in traffic accidents who used their own personal time to help the police in an investigation. The company said that it would meet the unions for discussion on the matter.