How to pass your 2024 HSE metalworking fluid inspection

If your manufacturing business uses metalworking fluids (MWFs) or coolants in your machining processes, the Health and Safety Executive (HSE) could visit your premises in the coming months. 

The regulator will run inspections from October 2023 to March 2024 to ensure employers are conducting regular health checks and adequately safeguarding workers against exposure to fluid or mist from computer numerical control (CNC) machines. 

What are the risks of metalworking fluids? 

Metalworking fluids fall under the Control of Substances Hazardous to Health (COSHH) Regulations 2002. This means employers must identify and minimise MWF dangers through risk assessments, safety controls, PPE, and staff training. 

Without correct measures in place, exposure to MWFs can cause a range of health issues, including: 

  • Skin irritation and dermatitis, particularly on the hands, forearms, and face 
  • Lung and respiratory problems following inhalation of MWF mist or vapours
  • Bacterial contamination caused by poorly maintained MWFs coming into contact with open wounds
  • Long-term illnesses, including occupational asthma, occupational hypersensitivity pneumonitis (OHP), and certain cancers

Your inspector’s top three MWF targets   

The HSE will be looking for three common MWF safety issues. Focusing your H&S efforts in these critical areas can help prevent fines and enforcement action, should an inspector arrive onsite. They are: 

  • Implementing and maintaining Local Exhaust Ventilation (LEV)
  • Performing routine fluid quality checks
  • Providing regular health checks for lung and skin conditions 

Get your business inspection-ready  

Proactive control measures protect your team from harmful MWF exposure – and help ensure a positive inspection outcome. Follow our three-step strategy to bring your business in line with regulations. 

Install and service LEV on all CNC machines 

Local Exhaust Ventilation (LEV) systems trap and eliminate MWF mists at their source, so your workers are less likely to inhale harmful vapours. It’s essential that you select the right model for your requirements and ensure it stays in good working order. 

  • Engage a competent supplier to design and install a LEV system to meet your needs. Using airflow indicators at the hood will demonstrate whether the ideal flow rate – and adequate protection – is maintained. 
  • After installation, keep your commissioning certificate within easy reach. This document outlines LEV maintenance requirements and the airflow rate your thorough examiner should look for during the system’s health check. 
  • Have your system thoroughly examined every 14 months by an insurer. 
  • Review the LEV follow-up examination report, usually emailed a few days after the service. Promptly act on any repair recommendations and keep the document for five years.
  • Record any checking and maintenance details in the system’s logbook. 

Run regular fluid quality checks 

Over time, bacteria can build up within metalworking fluids. The bacterial growth affects machinery performance and poses infection risks for workers who come into contact with contaminated MWFs. 

Regular fluid checks keep equipment working correctly and maintain appropriate pH and bacteria levels. You should commit to: 

  • Daily visual and odour inspections  
  • Weekly concentration, pH, and dip slide tests 

These simple assessments require basic, readily available tools. These include: 

  • Dip slides for bacteria testing
  • An incubator to provide a controlled and stable environment for bacterial growth
  • A refractometer to check concentrations
  • PH paper test strips or an electronic pH meter to measure acidity and alkalinity

Track exposure with staff health surveillance 

Even with preventative controls in place, you’re still legally required to conduct health surveillance to pinpoint exposure to metalworking fluids or mist. These need to be carried out by an occupational health professional. 

Your health surveillance programme will be shaped by a risk assessment to determine the level, frequency, and duration of exposure on your site. It will most likely include: 

  • Pre-employment health questionnaires to establish baseline readings for new hires
  • Routine health checks to monitor changes following MWF exposure
  • Lung function tests to evaluate respiratory health
  • Skin assessments to diagnose emerging conditions

Questions about your MWF inspection? Speak to an Opus specialist 

To understand your legal requirements and prepare for an upcoming metalworking inspection, talk to the Opus team. From maintaining your LEV system to introducing health surveillance, we’ll provide expert support for every HSE target area. 

Get in touch on 0330 043 4015 or email