Posted By Kevin Drew My employer is planning to demolish several substantial concrete structures within a building using a large mechanical breaker/pecker. The breaker, which will be hired from a local contractor, is a diesel powered 18 ton slew or similar. Amongst a multitude of hazards associated with the work are those posed by the emission of diesel fumes. The work will take many weeks. I have copy of HSG187, control of diesel engine exhaust emissions in the workplace and some of the control measures already exist. The building is well ventilated. I want to arrange for additional filtering of the exhaust emissions but I am struggling to find a company who can supply. Any filters we have tried to use for similar work in the past have melted, ignited or fallen apart very rapidly due to the high temperature of the exhaust tail pipe. Is there anybody out there who has had to deal with this type of problem before? All advice gratefully received. Kevin Drew

Posted By Jane Blunt Speaking from experience of dealing with internal combustion engines indoors, can I suggest you get hold of a carbon monoxide detector? It is a gas, so a filter does not remove it. Jane

Posted By Kevin Drew In response to the two replies so far:- Stuart - tried the ducting/piping away of fumes on a smaller scale task and it just about works although the pipe becomes extremely hot. We tried a water cooled jacket and it just fell apart. This work is on a much larger scale and the breaker needs to be mobile. Jane - HSG187 indicates that carbon monoxide is unlikely to be a major problem - it is the particulate that is more of an issue. On a more macabre note, if you choose to end it all with a hose from your car exhaust, etc you are unlikely to be successful if the choosen vehicle has a diesel engine. I hasten to add that this is just hearsay and stand to be corrected. Please keep the comments coming. Kevin Drew

Posted By Ron Hunter Would it be possible to use a hydraulic actuated breaker with the diesel power pack outside? (Just a thought - risk assessment first principles and all that!)

Posted By Jane Blunt Thanks John, I had been unable to find any figures, although the perceived wisdom from a number of publications was that CO levels from diesel exhaust were generally lower than from petrol engines. However, I could not find any figures to show how much, if any, this difference was in the 'real world'. I cannot find anything in HSG187 to indicate that CO is unlikely to be a problem - it indicates that the measurements they have done have all shown levels under the OES - this is not quite the same thing. I would definitely monitor for CO, following my own personal experience: A contractor, in his method statement, stated that he would use an electric saw to cut some concrete flooring. Unknown to us, he found the electric saw did not do the job quickly enough so he brought in a petrol driven saw, and worked away all morning, with the windows wide open and the door to the rest of the building closed. I was alerted to the 'problem' when someone on the opposite side of the building rang to report that his CO monitor, which was inside his laboratory, had gone into an alarm condition. Investigation showed that the CO levels in every part of the 3-storey building were slightly above the OES. Some areas had reached over 5 x the OES (more than 150 ppm), and people in that area were reporting symptoms. This reporting was genuine, because they had no idea what had been going on in the building. People in these areas were evacuated for the remainder of the day. The room where the job was being carried out was at about 50 ppm, even with the window wide open. It appears that the fumes were going into the building via the ceiling voids and thence being recirculated by the building ventilation system, spreading it to every part of the building, rather than being diluted and removed outdoors. The building is big - around 50 000 cubic metres, so this was not a trivial quantity of CO, and it took hours of ventilation and monitoring before I was satisfied that the incident was over. The contractor, on being brought in to 'discuss' the incident said 'we have never had any trouble before and we have worked in various Supermarkert buildings etc'. However, they had never actually checked on CO emissions. We strongly advised them to embark on CO monitoring in future, and also not to make a material change to the operating procedure without informing the client. Therefore, unless diesel exhaust CO levels are 1/5th or less than petrol exhaust levels, I would monitor. Jane

Posted By John Murgatroyd http://www.gpmu.org.uk/hs/health/msg00014.html http://www.hse.gov.uk/research/rrpdf/rr252.pdf http://www.fleetguard.co...pfilter.jsp?SMSESSION=NO All the filter manufacturers seem to have the same viewpoint, the diesel engine must run on low-sulphur fuel. Which excludes most construction machinery in this country then.