Metalworking Inspections: Looking After Your Metalworking Fluid

23 November 2023

Maintenance of fluid quality is key to controlling risk

The Health and Safety Executive (HSE) has announced that it will be inspecting manufacturing businesses that use metalworking fluids or ‘white water’ in their machining processes until March.  One of the common reasons that manufacturing companies, particularly smaller businesses, fail compliance is that regular fluid quality checks have not been completed.

HSE have put together a guide on how to look after your metalworking fluid and some reminders.

• Water-mix metalworking fluid deteriorates over time and can become contaminated with harmful bacteria and other contaminants.
• Irritated skin and lung problems don’t have to be associated with working with metalworking fluid if you take the right precautions.
• Maintaining fluid quality also improves machine performance and quality of machined components.
• Fluid quality checks are simple to carry out with some basic equipment
• Visual and odour checks should be done daily
  • Concentration, pH and dip slides should be weekly
  • If results are outside of recommended levels, you should take corrective action

Basic equipment needed

• Dipslides (bacteria)
• Incubator
• pH test strips (or electronic pH meter)
• Refractometer (concentration)

Who should do the fluid quality checks?
Whilst the requirement to have appropriate fluid quality checks in place is with the user of the metalworking fluids, the checks themselves can be carried out by users, the supplier, another third party, or a combination.

The important thing is that the checks are carried out at the recommended frequencies and corrective action is taken if the results are outside recommended levels. If the checks are being carried out by a combination of parties, it needs to be clear who is undertaking which checks to ensure none get missed.

Guidance and downloads
For explanations of the checks required and frequency, and technical advice on the methods and information on actions to take based on the results:

• visit the HSE website to download HSE COSHH MW5: Managing fluid quality
• view the Good Practice Guide for Safe Handling and Disposal of Metalworking Fluids (.pdf)
• record results download the printout checklist (.pdf)
• print and display the poster (.pdf) as a reminder of what’s needed and when
• watch the practical series of UKLA videos with easy-to-follow demonstrations