Respirable Crystalline Silica Levels in Foundries

Following the recent introduction of the new workplace exposure limit (WEL) for respirable crystalline silica and the implementation of the Silica Social dialogue agreement, Cti environmental have examined the results of 2 years of testing within the foundry industry to give an indication of how levels of silica are controlled.

The bulk of the data comes from measurements on vibrating bed knockout units and this is expressed graphically below.

The graph shows that 28 results are below the action level of 0.05 mg/m3,

12 results between the action level and the WEL of 0.1 mg/m3 and 5 results over the WEL

The instances where operators are exposed to levels over the maximum are generally due to poor extraction or operatives working outside of the effective area of extraction.

Where castings were knocked out by hand 25 % of results were above the action level of 0.05 mg/m3 but below the WEL of 0.1 mg/m3. The sample size however was small and because of this an accurate analysis could not be carried out.

In the area of feeder head knockoff 15 % of results were below the action level of 0.05 mg/m3, 15 % were between the action level and the WEL of 0.1 mg/m3 and 70% were above the WEL .

The very small sample from rumbler operations all gave results under the action level.

The requirements of current legislation will mean that the HSE will be expecting all results to be below 0.1 mg/m3  and action being taken(including the implementation of medical surveillance) where the results are above 0.05 mg/m3. In addition, results of monitoring and action plans for improvement will need to be submitted as part of the Silica Social dialogue agreement.

It is important therefore for all foundries to ensure that risk assessments are made and measurements carried out on all employees potentially exposed to crystalline silica. This will then enable action plans to be drawn up where improvement is necessary.

For further information, please contact Chris Mills or Jon Donohoe at Cti environmental

Jon Donohoe