HSE change in guidelines for MWF's

Based on recent updates, the HSE has revised its previous guidance values for monitoring personal exposure to Metal Working Fluid (MWF) mist, with the focus now on the removal of any MWF mist. Historically, oil mist had a limit within EH40, but this has now been removed. Water-mixed metalworking fluid has never had a limit.

The reason for the absence of a Workplace Exposure Limit (WEL) for both substances is that the HSE no longer considers any level of exposure to be safe. MWF exposure should be controlled to a level as low as reasonably practicable (ALARP). Using only air monitoring to measure exposure is no longer accepted, this may mean for some businesses a change in old practices and new control measures implemented.

It is crucial to maintain control measures to protect workers from potential health risks associated with MWF exposure. The HSE expect employers to use local exhaust ventilation (LEV) to control MWF mists. Employers have a legal obligation to test and maintain systems in line with HSE guidance HSG258 ‘Controlling airborne contaminants at work’.

While employers enclose many processes using MWF, mists may still escape during use , which is why it is essential to continue to measure using:

  • Dust lamp (Tyndall beam) observations
  • DRAMs (direct read aerosol monitors) at oil mist recirc / discharge and inside enclosures after smoke clearance time)
  • Smoke Clearance Time for Oil Mist enclosures

Following these changes by the HSE, the approach to LEV testing and exposure assessments in relation to MWFs will be altered. If you need to speak with a DevineAir consultant about your concerns or would like to install an LEV system, contact us here.

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