Posted By Geoff Burt A client has contracted OH Consultants to measure the amount of dust their Plant Operatives are being exposed to. The Consultants report quotes exposure levels for the total dust without any attempt to separate out the individual components (we need exposure levels for the cement and lime content of the dust). We have tried to explain this to the Consultants but are not getting any further with it. Is it possible to separate the different substances (at a reasonable cost) and are there any specialists out there who could advise on a company in the South East who could do this. Thanks Geoff

Posted By Paul Leadbetter Geoff Assuming that the consultnats already employed are competent, we can reasonably sure that the figures already quoted (for total dust exposure)are accurate. However, if the need for assessment of exposure to cement and lime was not made clear before the sampling was carried out, it may not be possible to give those figures because, for example, the type of filter used may be inappropriate. Unless otherwise required, the standard filter for air monitoring is the GF/A which contains a lot of calcium; it is, therefore, not suitable for determination of calcium. Determination of calcium would be necessary to measure personal exposure to lime (which contains calcium). However, I am unsure how you would determine cement dust (which contains many substances, including calcium silicate, lime and silica - all of which have occupational exposure limits) other than assuming that all of the dust collected was cement. Feel free to contact me directly if you would like to discuss the matter in more detail. Regards Paul Leadbetter