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Metalworking Fluids and Allergic Contact Dermatitis.

Updated: Oct 20, 2023

Precision engineering often involves intricate and precise metalworking processes which are carried out using specialist lathes, milling machines and saws. With these processes, the metalworking fluids used to lubricate and cool the workpiece pose a significant risk to health through inhalation and fluids coming into contact with the skin.

Essentially, there are three types of metalworking fluids that are used in these types of processes:

  • Mineral Oils - a mix of mineral-based oils of different viscosities and additives used to gain a specific characteristic.

  • Soluble Oils - Soluble water-in-oil cutting fluids (water-mix metalworking fluids) are mineral oils that contain emulsifiers and additives. Some include rust inhibitors and bactericides.

  • Synthetic Fluids - Cutting fluids with solutions of non-petroleum-based fluids, additives and water.

Metalworking Fluid

Allergic Contact Dermatitis (ACD)

Metalworking fluids (MWFs) are essential in the machining process, providing lubrication, cooling, and cleaning. However, exposure to MWFs can lead to the development of allergic contact dermatitis (ACD), a type of skin inflammation that occurs when the immune system reacts to a specific substance in the MWFs.

ACD can cause a range of symptoms, including redness, itching, and blistering, and can be a significant occupational hazard for workers in the metalworking industry. Here are some ways to prevent ACD caused by exposure to MWFs:

  • Use less hazardous MWFs: Choose MWFs that are less likely to cause ACD, such as synthetic or semi-synthetic fluids.

  • Wear gloves: Use gloves made of materials that are resistant to MWFs and change them frequently to avoid prolonged exposure.

  • Implement proper hygiene practices: Wash hands and exposed skin thoroughly with soap and water after handling MWFs, and avoid touching the face or other parts of the body until after washing.

  • Use proper ventilation: Ensure that proper ventilation is in place to reduce the concentration of airborne MWFs.

  • Use personal protective equipment: Use respiratory protection such as a properly fitted respirator to prevent inhalation of MWF mist.

  • Regular monitoring: Conduct regular monitoring of MWFs for bacterial and fungal contamination to minimize exposure to microorganisms that can cause skin irritation.

  • Provide training: Provide comprehensive training to workers on MWF handling, use, and storage, and establish protocols for safe work practices.

  • Keep equipment clean: Clean machines, tools, and work surfaces to minimize the accumulation of MWFs on surfaces.

  • Rotate workers: Implement job rotation to minimise prolonged exposure to MWFs and to give workers a break from exposure.

In summary, ACD caused by exposure to MWFs is a significant occupational hazard for workers in the metalworking industry. By implementing proper hygiene practices, providing personal protective equipment, and using less hazardous MWFs, employers can help to prevent the development of ACD and maintain a safe and healthy workplace.

Metalworking Fluid

Allergic alveolitis

Allergic alveolitis, also known as hypersensitivity pneumonitis, is a type of lung disease that can be caused by the inhalation of certain substances, including metalworking fluids. When these fluids are sprayed or misted during metalworking operations, they can release tiny particles into the air that can be inhaled into the lungs. In some people, this can trigger an immune response, leading to inflammation and damage to the tiny air sacs in the lungs called alveoli.

Symptoms of allergic alveolitis can include cough, shortness of breath, fever, and fatigue. These symptoms may develop over time with repeated exposure to the offending substance or may appear suddenly after a single exposure. In severe cases, allergic alveolitis can lead to permanent lung damage or even respiratory failure.

Treatment may involve avoiding exposure to the offending substance, using medications to reduce inflammation and improve breathing, and, in severe cases, oxygen therapy or even a lung transplant.

Here is a ten-step summary of a metalworking fluid management system to protect worker health:

  • Prevent spills of MWFs: Prevent exposure to workers and minimize environmental impact. Provide emergency spill kits to help contain any spills.

  • Maintain fluid levels: Maintain MWF levels within the recommended range to prevent contamination and ensure effective cooling and lubrication.

  • Clean machinery: Implement regular cleaning of machinery to prevent the build-up of contaminants and maintain the performance of MWFs.

  • Inspect and maintain equipment: Conduct routine inspections and maintenance of MWF delivery systems and filtration units to ensure they are functioning Select appropriate MWF: Choose MWFs that are free of harmful chemicals and are compatible with the machinery and workpiece materials.

  • Train workers: Provide comprehensive training to workers on MWF handling, use, and storage, and establish protocols for safe work practices.

  • Conduct routine monitoring: Conduct regular monitoring of MWFs for contamination and implement procedures to dispose of used fluid.

  • Implement ventilation: Ensure that proper ventilation is in place to reduce the exposure to airborne contaminants.

  • Use personal protective equipment: Provide workers with appropriate personal protective equipment, such as gloves and respirators, to minimize the risk of exposure.

  • Control leaks: Take measures to control leaks properly.

  • Record keeping: Keep accurate records of MWF usage, maintenance, and monitoring to track the performance of the system and identify areas for improvement.

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We hope this article goes some way to providing a brief overview of the risk to health through inhalation of, or contact with, metalworking fluids. If you wish to know more on this subject or need support from our team then please feel free to get in touch with us through social media or our website (, by email at or simply give us a call on 01709 931299.


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