Posted By WTaylor I did some research on this last year. Our system is 90psi, but our guns reduce the pressure to under 30psi. From what I've read it's generally accepted that below 30psi there are no health effects. However, blowing wood-dust around does increase the risk of inhalation and eye injury, which we've had to control with goggles and dust-masks. But this is for short periods only. Don't ask me to convert psi into bars! lol Will

Posted By Casanova Damn, There goes my noms de guerre.

Posted By Geoff W 90psi = 6 bar

Posted By Bossa nova Byron, This contains some facts about injury, http://matcmadison.edu/f...pdf/Compressed%20Air.pdf Bossa nova

Posted By Chris Packham There are simple, air operated, hand held guns that appear very similar to a normal blow gun, but that actually use the compressed air to create a vacuum and thus to suck up any dust and transfer it into a bag or through a hose to a suitable container. Cheaper and less cumbersome than an electrically operated vacuum. I think you will find these in the RC Components catalogue. Chris

Posted By Phil Grace Oh dear oh dear.... I can not believe that this forum is discussing this subject. I agree with the comments from other posters about the undesirability of this practice. But what concerns me is the large number commenting on which pressure to use. It would seem that there are many workplaces where "blowing down" is still routine and/or accepted practice. I just can not accept that, in 2008, it is still regarded as acceptable to blow down/off workbenches, workpieces etc. It is a practice that does nothing but spread any dust around, putting into the workplace atmosphere and making the smaller particles breathable. And as some people have commented at higher pressures larger particles can become dangerous projectiles. And then there is the depressing aspect that the presence of airlines in the workplace may offer temptation for horseplay. Finally, if anyone isn't convinced they should visit the HSE's LEV site where the levels of dust generated by common working practices are graphically illustrated by short videos - including one on use of an airline for cleaning. Phil

Posted By Merv Newman While I would agree that sucking rather than blowing would be good practice there are many practical situations wherein sucking is nowhere near as practical as blowing (how do you get 1 mm of dust from a sticky 2mm hole ?) Airline pistols are usually limited to 2 bar (1.97 At ?) to avoid the 6 bar "blowing through the skin" factor.(Apocryphal or not ? you tell me) While I may not like blowing I have, over the years, had to accept that there is little practical alternative; so long as the pistols are limited and the operator and bystanders are protected from potential blow back. Your RA may say different but let's be practical here. Merv

Posted By Pete48 You can check around the worlds safety info sites and you will find a consistent statement that using compressed air to clean down workplaces is either "a dangerous practice" or one that is written as "don't" or "never" use compressed air to clean--- This is good guidance that should be followed in most workplaces. However, where there is no other option than to use compressed air to clean or blow down materials, then the design of the safe system of work is critical. Most countries quote that the pressure should be limited to the minimum pressure required to achieve the cleaning and in any event not exceed 2 barg (30 psi), adequate ppe must be worn and the design of the blow gun should consider chip guards, extension tubes or guns equipped with injection exhausts and particle collection bags. Others have highlighted the other risks created by the use of blow guns, so I will not repeat them here. The accidents and injuries are real and not confined to the UK. Many of the stories that people quote are, however, from accidents involving horseplay or using the air to clean clothing or hair. Injuries can occur at very low pressures if the supply is misused and also the gun does not need to be placed on the body for injury to occur. There are cases of rectal and colon injury from distances up to 50cm away at pressures of 3 barg for less than a second. Injuries to the eardrum are also on record. So in summary, compressed air is a workplace hazard that requires specific risk controls. There is plenty of guidance out there around the web or from the industry associations such as http://www.britishcompressedairsociety.co.uk Usual disclaimer that I am not connected to BCAS in any way.

Posted By BB Hi Bryon, As Merv has said, sometimes blowguns are a necessary evil. However, there are some top-notch suppliers out there that can supply excellently designed, safer, quieter, more economical-to-use units. These are also designed specifically with safety as priority. In the past, I have used Silvent units (there are other manufacturers too) and in my opinion, they were a vast improvement over the £5 specials available in some tool supply catalogues. Of course, they were also more expensive. OSHA have done heaps of work on this and set guidelines on pressure requirements. This tends to be often referenced and in the absence of anything closer to home, is worth taking into account.