Metalworking Fluids (MWFs)

Cooling lubricants (CMLs) - Metalworking Fluids (MWFs): Increase Efficiency and Reduce Air Pollution at the Workplace

In modern industry, particularly in metal-cutting applications, metalworking fluids (MWFs) are indispensable. They make a significant contribution to the efficiency of manufacturing processes, improve the quality of workpieces, and extend tool life. At the same time, however, they also create challenges, particularly with regard to air quality at the workplace.

MWF aerosols, oil mist, and vapours can affect employees’ health and require targeted air-purification measures.

This article explains how metalworking fluids are used, which risks are associated with them, and which solutions companies can implement to effectively reduce air pollution caused by MWFs.

What Are Metalworking Fluids (MWFs)?

Metalworking fluids are special substances used when cutting and forming materials. Their main functions are:

  • Cooling the machining area
  • Lubricating tools and workpieces
  • Flushing away and removing chips
  • Reducing friction and wear

By using metalworking fluids, companies can:

  • Improve the surface quality of workpieces
  • Achieve higher machining speeds
  • Extend tool service life
  • Reduce production costs

Despite alternative processes such as dry machining or minimum-quantity lubrication, metalworking fluids remain the predominant solution in practice.

Types of Metalworking Fluids

Different types of metalworking fluids are used depending on the application.

1. Non-Water-Miscible Metalworking Fluids

These fluids are supplied ready for use and are characterised by particularly high lubricating performance. They are primarily used in applications involving high pressure loads.

Typical applications:

  • Drilling
  • Turning
  • Thread cutting
  • Broaching

2. Water-Mixed Metalworking Fluids

These fluids consist of an emulsion of water and oil or grease, together with various additives. They are used when large amounts of heat must be dissipated.

Typical applications:

  • Grinding
  • High-speed machining
  • Processes involving intensive heat generation 

Air Pollution Caused by MWFs: An Underestimated Risk

The use of metalworking fluids inevitably produces aerosols, vapours, and oil mist that contaminate the air at the workplace. These substances may present health risks to employees.

How Are MWF Aerosols Generated?

Aerosols are extremely fine liquid droplets suspended in the air. They are generated by:

  • Metalworking fluid being thrown off at the machining point
  • Mechanical movement of tools
  • Atomisation caused by compressed air

How Are MWF Vapours Generated?

Vapours are primarily generated by:

  • Heating of workpieces and tools
  • Hot chips
  • Evaporation of metalworking fluids from surfaces

In practice, aerosols and vapours usually occur together and form a complex mixture of airborne particles.

Terms Relating to Air Pollution Caused by MWFs

A better understanding of the most important terms helps to assess the issue correctly:

  • Aerosols: Finely dispersed solid or liquid particles in the air
  • Oil mist: Extremely fine oil droplets suspended in the air
  • Oil vapour: Gaseous hydrocarbons
  • Oil smoke: Solid particles generally produced by combustion
  • Emulsion: A mixture of oil or grease and water containing additives

These substances can enter the respiratory tract and cause long-term health problems.

Health Risks Caused by Airborne MWFs

Exposure to metalworking fluids affects not only the skin but also the respiratory tract. Possible effects include:

  • Irritation of the eyes and respiratory tract
  • Skin conditions caused by direct contact
  • Allergic reactions
  • Long-term respiratory diseases

It is therefore essential for companies to implement suitable protective measures.

Measures for Reducing Air Pollution Caused by MWFs

To improve air quality at the workplace, companies should implement a comprehensive concept.

1. Extraction Directly at the Source

The most effective method is to capture emissions directly at their point of origin. Modern extraction systems:

  • Remove aerosols and vapours immediately
  • Prevent them from spreading throughout the room
  • Ensure clean air within the working environment

2. Use of Air Filtration Systems

High-quality air filtration systems can remove even the smallest particles from the air. They are particularly effective for:

  • Oil mist
  • Aerosols
  • Fine dust

3. Process Optimisation

Emissions can be reduced by making adjustments to production processes:

  • Minimising the use of metalworking fluids
  • Optimising machining parameters
  • Using modern machinery

4. Regular Maintenance

Well-maintained systems generate fewer emissions. Important measures include:

  • Cleaning the machinery
  • Replacing filters
  • Monitoring the quality of the metalworking fluid

5. Employee Training

Employees should be informed about the correct handling of metalworking fluids. This increases safety and reduces risks.

Benefits of Clean Air in Metalworking

Improving air quality offers numerous benefits.

For Employees:

  • Better health
  • Fewer sickness-related absences
  • Greater satisfaction

For Companies:

  • Compliance with statutory requirements
  • Reduced downtime
  • Higher productivity
  • A positive working environment 

The Future of Metalworking Fluids and Air Purification

As occupational health and safety requirements and environmental standards continue to increase, the importance of clean air will grow further. Companies are increasingly using:

  • Energy-efficient filtration systems
  • Automated extraction solutions
  • Sustainable metalworking fluids

These developments help to further reduce exposure to metalworking fluids while simultaneously increasing production efficiency.

Conclusion: Efficient Production and Clean Air Are Not Mutually Exclusive

Metalworking fluids are indispensable in modern metalworking. They offer numerous benefits for production but also create challenges for air quality at the workplace.

Through the targeted use of extraction and filtration systems, optimised processes, and regular maintenance, companies can significantly reduce exposure to MWF aerosols and vapours. This makes it possible to combine productivity, cost-effectiveness, and occupational health and safety in the best possible way.

A clean working environment is not only a statutory requirement but also a decisive factor in long-term corporate success.

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