Posted By holmezy Hi all, A part of our organisation is a stone workshop where we machine and process granites, sandstones, marbles etc. Within a production workshop that is approx 20m by 40m we have a stonemasonry area in one corner approx 8m by 5m. The work in this area involves general handwork with hammers and chisels to the use of angle grinders to finish the stone which varies in size from "football" size to "wardrobe" size. The existing LEV is an "elephants trunk" type system which is due for replacement. Creating an enclosed area is not a pheasible option due to access, cranage requirements, downdraught benches might be awkward due to size etc so what sort of LEV would be suitable? Suppliers seem to want to replace the old system with new trunks, which as I understand, are possibly not the most effective depending on operator usage? Also, what capture and face velocities would I require to cope with handwork and angle grinders? The employees currently wear airstream RPE in this area but not outside, and the boundaries are very vague. Last time we carried out air sampling the RCS levels in the main factory were below the 0.1mg/m3 and in the masonry area they were 0.1 - 0.2mg/m3 ish. I do understand LEV'S in a rudimentry fashion and have got HSE258, but it seems that I have to be an expert to make sure that I get a good supplier and good system that does what we require? Any help gratefully accepted. Holmezy

Posted By Chris Packham Holmezy Downdraft benches can actually be quite compact, particularly if designed to fit a particular space. They are also in my experience much more effective that the elephant trunk type of LEV, especially with angle grinders, where the peripheral velocity of particles make them difficult to capture. If you think it might help, feel free to get in touch and I will see what I can do to help you get started. Chris