Morning everyone,

I'm trying to update risk assessments in a welding workshop, where they do primarily MIG and flame cutting. I have to admit that its a bit out of my comfort zone.

I can't find any evidence of any previous air sampling being done and the work shop only has general ventilation with the welders have powered air fed RPE.

Reading a previous post one person advised that rather than spend time/money air sampling it was best to just assume the level of fume was over the WEL and spend the money on good local exhaust ventilation. This seems to make sense but I know I'm going to have to have my facts straight before I talk to management.

I started reading the TWI website and it got a bit technical.

If anyone could offer advice on a stratergy to get a good risk assessment that protects but doesn't go over the top I'd be eternally grateful.

You haven't given us enough information to say. There would normally be significant quantities of nuisance particlate from MIG welding, so ventilation should be provided.

You need to say what materials you are welding - for some materials very large quantities of ozone are emitted.

Flame cutting can produce large quantities of nitrogen oxides.

I agree with Gerry. Extraction is important.

The other thing you need to bear in mind is that although your welders are being protected by power fed RPE, anyone else going in there isn't. You also need to be aware that the finer particulates from welding don't fall to the floor quickly - they hang around in the air for a long time. They are best removed at source.

Yes, I would recommend local exhaust ventilation. Air sampling is then not needed.

Bob, thats effectively what we've been doing for years, but my concern is that we don't really know if the exposure has been over, close to or under the WEL - so my logic says if we want to continue doing this we'll need to sample to prove its below the WEL. Where would we stand with regard to 'as low as is reasonably practicable' rather than just squeaking under the WEL?

to further complicate things its classed as an indoor workplace and the guys are saying its too cold with all the doors open. How do we maintain 16 degrees C whilst maintaining the air flow?

FG - EMF?! I'll add it onto my list of questions to ask on the forum!! LOL

Thanks for all the advice, i really appreciate the help.

Hi all,

This has been touched on earlier, but surely you need to carry out some air monitoring after the installation of the LEV otherwise how do you know it's working effectively?

As Gary points out air monitoring must be carried out every 14 months to assess exposure levels.

Health surveillance.......

The procedure accodring to which you have to do this is: 1.Remove grease and all surface coatings first, unless they are meant to be welded or cut through. 2.Arrange work so that the worker’s head is out of the fume. 3.Confirm that extraction is turned on and working. 4.Adjust a moveable welding hood so it collects hot fume rising. The hood should be within one duct diameter of the welding point. 5.Workers should stand to the side of a booth, not in the air flow. 6.Check for gas leaks. Also a little bit about equipment's: 1.Provide a good standard of general ventilation; 5-10 air changes per hour, with a through draught. 2.Provide an extracted welding booth, an extracted workbench or a moveable capture hood. See illustrations 3.You may also need to use respiratory protective equipment (RPE) 4.You need an air speed of at least 2 metres per second into an extracted welding bench.​​​​​​​