Are you working safely with metalworking fluids?

Matt Bloomer, technical services manager at Q8Oils, outlines legislative requirements in the use of metalworking fluids and highlights some considerations for safe working.

Anyone working with machine tools will be aware of the importance of metalworking fluids. They are a vital part of the metal manufacturing process, providing lubrication and cooling, and can result in more effective tooling and protect and prolong the life of the machine.

Metalworking fluids in use, however, can be hazardous through direct contact with the skin and through inhalation as they can generate a mist during machining operations. Under poor conditions the fluid and the mist can irritate the eyes, nose and throat and lead to health problems ranging from skin disorders to serious respiratory diseases.

In 2017 the Health & Safety Executive (HSE) launched a proactive inspection programme to focus on areas of manufacturing where workers may be at risk of exposure to asthmagens and/or carcinogens generated during the production process. The HSE wants to ensure that the risks are properly managed and reduce the incidence of serious health effects from exposure. Metalworking fluids have been highlighted as a main area of focus.

Most employers will be aware that they have a duty of care to take adequate measures to protect their operators from harmful exposure. This is enforced bylaw under the Control of Substances Hazardous to Health Regulations (COSHH) 2002.

What are the main legal obligations?

Under COSHH regulations, employers must:

• Carry out a sufficient risk assessment for workers who come into contact with metalworking fluids


• Identify measures to control and reduce exposure


• Keep records of fluid checks and retain these for five years


• Provide a suitable health surveillance programme


• Keep records of exposure to hazardous substances and employee health records for 40 years

The recommended or permissible level of oil particulates in working environments varies widely by country. In the UK, the HSE withdrew its previous lowest recommended exposure limit (1mm/m³) after cases of ill health were reported following exposure at this low level. Research is ongoing and the HSE is committed to improving indoor air quality in manufacturing environments.

HSE inspections: what to expect

An HSE inspection may sound alarming, but its aim is to assess and highlight areas for improvement. An inspector will look at control systems and consider whether reasonable measures are being taken to reduce exposure. Fluid management processes and record keeping are also reviewed.

The HSE takes an ‘APC’ approach to risk management based on Avoidance (e.g. avoiding exposure through working practices), Protection (using correct PPE) and Checking (monitoring and reporting systems and health).

Choosing the right metalworking fluid

To minimise the risk of exposure, using the right metalworking fluid (MWF) is a good starting point. Choice is largely dictated by the application, but it is important to identify the best product that combines safety, performance and economy. Metalworking fluids are developed with these principles in mind and their component makeup varies to suit the application. The components in a formulation may be critical to the application but can also be hazardous. Achieving the correct balance of effectiveness versus potential harm is always a challenge.

It is important to consider the quality of the MWF during the full machining cycle. In the long term it may be safer and more economical to use a more expensive product which provides a longer fluid life and greater protection to the operator from exposure to harmful microorganisms.

The complex composition of a metalworking fluid varies widely, and lubricant manufacturers are required to provide a CLP complaint safety data sheet which details its basic properties and gives information on hazardous components and exposure. It is important to stress that the hazard classification for soluble metalworking fluids relates to the concentrated product as supplied; when diluted, any hazard is significantly reduced.

Dangers associated with the mist generated by metalworking fluids are not always obvious. Even though some fluids are less hazardous than others, remember that there is no such thing as a healthy mist!

It is vital to maintain the concentration and optimum operating conditions for metalworking fluids within the limits recommended by the lubricant supplier. These are usually shown on a product data sheet. It is advisable to display a fluid monitoring chart which includes the recommended operating conditions on individual machines or nearby notice boards.

Fluid monitoring and equipment checks

Metalworking fluids are usually used in an open system and are susceptible to contamination over time. This could be chemical contamination, such as tramp oil, or by microorganisms, in particular bacteria, fungi and yeast.

It may be obvious when a fluid is contaminated, for example a noticeable foul odour, but some changes are more subtle and difficult to detect. The only certain way to evaluate a fluid’s condition is through regular monitoring and testing, based on HSE guidelines. It is also vital to have an adequate filtration and LEV extraction system in place and to carry out regular checks and maintenance, including a thorough inspection every 14 months by a qualified ventilation engineer.

Find out more

There is plenty of advice to help companies follow best practice in working safely with metalworking fluids and comply fully with legal requirements.

The Good Practice Guidance for the Safe Handling and Disposal of Metalworking Fluids was recently launched by UKLA’s Metalworking Fluid Product Stewardship Group in partnership with HSE. Q8Oils was a key member of the advisory panel of industry experts set-up by the Group to compile the guide.

Q8Oils offers a wide range of high-quality metalworking fluids and cutting oils, based on the latest technology and can advise on the best option for your application. We can also offer advice through our QCare support service on how to comply with COSHH legislation and carry out fluid monitoring services, including onsite visits.

Q8Oils www.Q8Oils.co.uk