Posted By Martin Taylor This is a bit of a legal technical one I am afraid but I am interested in checking my opinion of the way that the Supply of Machinery regs deals with noise in the design and supply of machinery. A supplier has offered us a machine with 2 options - 75dB and 80dB with additional costs for the former due to noise abatement enclosure. My understanding from the machinery regs is that the design should reduce the airborne noise to the lowest practicable level and as such the supplier can not legally put the 80dB machine on the market. Obviously when I tell my engineers this (and the supplier as well) they are not too happy. Anybody out there like to back me up or shoot me down? thanks Martin

Posted By Martin Taylor thanks for the feedback Rodger - it's good to get some support on this one - it feels as though I am the only one interested in doing things right with this one - anybody else out there with views? ta Martin

Posted By Paul Grady If you look as the EHSR's they give you the various control measures, from the top of the scale "eliminate the risks" to the lowest level of protection "adequate instruction". I always say there are two parts to any machine supply. 1. Fit for intended use. Where a manufacturer can believe how a machine will be used, in ideal conditions (that may include "no personnel in the vicinity") 2. Fit for application How a purchaser will actually use the machine.(i.e. the personnel involved, the way the User Company will use and apply the machine). You find the OEM usually claims to be suitably vague about the detail of the eventual use. A level of control options are offered by the Manufacturer. Its up to the user to carry out suitable risk assessment to match the level of controls to his application. This is a necessary 'sliding scale' to meet the reasonably practicable criteria.

Posted By D. Hilton Martin This is an interesting problem, the requirements of Directive 98/37/EC relating to noise emissions from machinery state: “Machinery must be so designed and constructed that risks resulting from the emission of airborne noise are reduced to the lowest level taking account of technical progress and the availability of means of reducing noise, in particular at source”. The ISO 1999 Standard, defines "hearing loss" as a permanent increase of the auditory threshold (the minimum audible sound level) affecting the intelligibility of speech. A double entry table is used to assess the percentage risk of "acquiring" hearing loss if exposed in the workplace to a certain average sound level for 8 hours per day, 6 days a week for a given number of years: for example, the case of an employee working at 6 days a week exposed to an average sound level of 95 dBA during an 8-hour shift and supposing that the employee started employment at the age of 17 and stays at this particular job until the age of 47, that is, a 30-year exposure. ISO 1999 reveals a 29 percent risk of suffering speech intelligibility handicap. That is, almost 3 out of 10 such persons will experience difficulties in understanding normal speech. Similarly, whenever working hours are halved, the criterion is applied subtracting 3 dBA from the actual sound level. Again, take for example, the case of an employee working 3 nights a week exposed to an average sound level of 106 dBA during a 4-hour shift. We have half the days and half the time per day, so 3 dBA must be subtracted twice, yielding 100 dBA. Suppose, further, that the employee started employment at the age of 15 and stays in this trade till 30 -- that is, a 15-year exposure and a 37 percent risk of suffering speech intelligibility handicap. That is, almost 4 out of 10 such persons will experience difficulties in understanding normal speech -- at the age of 30. A closer look at ISO 1999 reveals that at 80 dBA the risk is 0% for any extension of working life. Applying the criteria of ISO 1999, we can see that the risk resulting from the emission of airborne noise at 80 dBA are 0% and similarly the resultant risk at 75 dBA is also 0% and if this criteria is used it could be said that the machinery was so designed and constructed that risks resulting from the emission of airborne noise are reduced to the lowest level. Regards Darren