We have the facility in our workshop to MIG weld small components, on a bench, up against a wall.
We weld very intermittently but our welder, who was fully protected, was doing some welding this morning which took about 10 minutes.
I have received a complaint from another member of the workforce complaining about the lack of a welding screen around the welding area, stating everyone else in the workshop are exposed to the UV light emitted.
The nearest anyone was to the light source was about 20' away, and they were undertaking there own tasks, not actually looking in the direction of the welding activity (hopefully).
Comments please.

Measurements of UV from a welding operation in this paper http://annhyg.oxfordjour...g/content/45/7/597.short give values in the following range:

Maximum was 7.85 W/m2 at 1 metre. Applying the inverse square law this will translate to 7.85/36 = 0.22 W/m2 at a distance of 20 feet (approx 6 m)

Minimum was 0.28 W/m2 at 1 metre, which translates to 0.008 W/m2 at 6 m.

The ELV exposure limit values as proposed in ‘A non-binding guide to the artificial optical radiation directive 2006/25/EC’ published by the Radiation Protection Division Health protection Agency suggests a worst case where the limits would be:

1 min at 0.5 W/m2, 5 min at 0.1 W/m2 and 1 hour at 0.008 W/m2.

The irradiance will depend on the current, and is higher as the welding current increases.

Theoretically, arc-eye shouldn't be possible more than 15 feet from the arc, however, reflective light can produce arc-eye at greater distances. What is important here is what the content of the risk assessment said, and if the author's comments were acted upon, for example, I would suggest that the wall at the back of the bench be painted with non-reflective paint, a screen or temporary barrier is erected whenever welding (arc) processes are undertaken and signage is displayed, informing all staff of the arc radiation activity.
If there were no suitable controls in place, a new risk assessment should be undertaken forthwith, and effective controls implemented as a priority.
Furthermore, the welder should have sufficient training to realise the effect (or potential effect) that arc-welding processes can have on others, this is not restricted to arc-eye, local exhaust ventilation should be provided, or other sufficient means of removing air-borne particles and fumes (Argon is an asphyxiant in high concentrations) and heat hazards should also be considered, along with fire fighting considerations and escape/evacuation plans.
Hope this is helpful,
Regards,
Roy

Cant you just wait and see if an injury develops, if it does its a riddor arc eye and possible claim, if not then treat it as a hazard observation / near miss and put in suitable control measures for the hazard.

If your personnel had safety glasses on in the Workshop, this may too have lessened the eye energy absorbed over the 20' distance. Also, doesnt UV light turn to Infa red over longer distances which can be less harmful than the UV... might be out on a wing with this one though lol.

An interesting technique for risk assessment!

I don't think there's any question about whether a screen should be provided here.

To my mind there's no question that a screen should be installed to prevent the possibility of employees being affected by the arc welding work.

The 2 things to really consider here is that you've had a complaint from another employee relating to a safety issue (think liability in the event of n accident/incident). Secondly, you've effectively stated that you cannot be sure that other members of staff would not look at the activity taking place (to quote Mr Deniro in 'Ronin' - When there is doubt there is no doubt) and regardless of the distance that they may undertake their own duties I'd guess there'll be a chance that they could be closer.