Control of legionella (and other) bacteria in metal working fluids (MWFs)

Legionella bacteria are commonly found in water supplies at low concentrations and if conditions (eg temperature and nutrients) are right, these microorganisms will grow. Water mix metal working fluids (MWFs) are mostly water and their industrial use may produce aerosols. Inhaling an aerosol contaminated with Legionella bacteria can cause Legionnaires’ disease. HSE guidance L8 “Legionnaires’ disease. The control of legionella bacteria in water systems” recommends that the MWF storage and distribution system of lathe and machine tool coolant systems should be cleaned and disinfected every six months or more frequently if recommended by machine tool or fluid suppliers.

However, the Health and Safety Laboratory has carried out research, Survival of Legionella pneumophila in metalworking fluids, which shows there is a minimal risk of Legionella bacteria contaminating such a system, if the system is properly managed.

HSE’s guidance on managing bacterial contamination of metalworking fluids suggests a risk-based approach, based on monitoring fluid condition and bacterial contamination: http://www.hse.gov.uk/metalworking/bacterial.htm

If you can demonstrate that metalworking fluids are managed in accordance with the COSHH essentials sheet Managing sumps and bacterial contamination (http://www.hse.gov.uk/pubns/guidance/mw05.pdf) and HSE’s guidance on managing bacterial contamination in metalworking fluids an additional assessment of the risk of Legionnaires’ disease is normally unnecessary. However, further assessment and precautions will be necessary to cover any special circumstances, such as deep cleaning of sumps and machinery with jet washers, where the potential for exposure to airborne hazardous bacteria is much greater. This is due to the disturbance of microbial slime known as biofilm – where Legionella may survive. Avoid water jetting where possible, as it tends to create fine water droplets or mists.

If water jetting is necessary carry out a risk assessment, to include respiratory and other risks such as those arising from the use of high pressure and electricity, see,

More guidance on metalworking fluids can be found on the HSE web page: http://www.hse.gov.uk/metalworking/index.htm

For more information on controlling the risk of Legionnaires’ disease, see Legionella and Legionnaires’ disease: http://www.hse.gov.uk/legionnaires/index.htm, or contact us on 07896 016380 or at Fiona@eljay.co.uk, ad we’ll be happy to help

Contains public sector information licensed under the Open Government Licence v3.0.

 

Metalworking fluids – ejector seat manufacturer fined £800,000 for failing to protect workers’ health

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Ejector seat manufacturer fined £800,000 for failing to protect workers’ health

A  manufacturer of ejector seats has been fined £800,000 after three workers developed debilitating lung conditions.

Three skilled CNC machine operators developed extrinsic allergic alveolitis after many years of exposure to the mist of working metal fluid. The lung condition, also known as hypersensitivity pneumonitis, is a body’s allergic reaction to breathing in a substance and symptoms include coughing, shortness of breath and joint pain.

Aylesbury Crown Court heard how the workers, who had served with the company for more than 20 years, were exposed to the working metal fluid mist over at least a three-year period. One worker has been so severely affected they have become virtually paralysed by the illness, another will never be able to work with metal working fluids again, a key material in the industry and a third must have special measures in place to ensure he never comes into contact with the substance.

An investigation by the Health and Safety Executive (HSE) found that the measures in place within the factory to stop the exposure to workers were inadequate. The fluid is commonly used as a lubricant and coolant in engineering processes. During the process of using the machines the fluid creates a mist, which in this case was breathed in by around 60 workers.

The manufacturer failed to put in place a system of cleaning away the excess fluid or providing extraction to prevent the build-up of the mist. There were also failings in the provision of health surveillance, which should have identified the issue early enough to ensure the company were able to put in place and monitor any appropriate safety measures.

The manufacturer pleaded guilty to breaching Section 2 (1) of the Health and Safety at Work etc. Act (1974) and Regulation 6(1) of the Control of Substances Hazardous to Health Regulations 2002 (as amended) (COSHH) and were fined £ 800 000 and ordered to pay costs of £36 912.36

The HSE said “Companies need to make sure they consider workers’ health just as much as their safety when carrying out risk assessments. The dangers of breathing in metal working fluid are well known within the industry. In this case one worker has had his health permanently and severely damaged, two others have also been affected, all will have to live with their condition for the rest of their lives.”

About metalworking fluids

Metalworking Fluids (MWFs) are neat oils or water-based fluids used during the machining and shaping of metals to provide lubrication and cooling. They are sometimes referred to as suds, coolants, slurry or soap.

The main health risks from working with metalworking fluids

Exposure to metalworking fluids can cause:

  • irritation of the skin or dermatitis; and
  • occupational asthma, bronchitis, irritation of the upper respiratory tract, breathing difficulties or, rarely, a more serious lung disease called extrinsic allergic alveolitis (EAA), which can cause increasingly severe breathing difficulties in recurrent episodes, following repeated exposure.

Fluid and mist from water-mix wash fluids and washing machines used to clean machined components may be hazardous in much the same way as fluid and mist from metalworking machines, and the same principles of risk assessment, prevention and control should be applied.

How harm is caused

Metalworking fluids are mostly applied by continuous jet, spray or hand dispenser and can affect your health:

  • if you inhale the mist generated during machining/shaping operations;
  • through direct contact with unprotected skin, particularly hands, forearms and heads;
  • through cuts and abrasions or other broken skin; and
  • through the mouth if you eat, drink or smoke in work areas, or from poor personal hygiene, eg not washing hands before eating.

Key messages for managing the health risks

Control of Substances Hazardous to Health Regulations (COSHH) requires exposure to metalworking fluids by inhalation, ingestion or skin contact to be prevented where reasonably practicable, or failing that, adequately controlled.

You should:

  • carry out a suitable and sufficient risk assessment – HSE’s self-assessment questionnaire (http://www.hse.gov.uk/metalworking/questionnaire.pdf) will help you do this;
  • maintain fluid quality and control bacterial contamination of fluids;
  • minimise skin exposure to fluids;
  • prevent or control airborne mists; and
  • where there is exposure to fluid or mist, carry out health surveillance.

To achieve the necessary control and risk reduction, among other actions, you will need to:

  • check and maintain exposure control measures, such as enclosures and local exhaust ventilation;
  • check levels of bacterial contamination using dip slides, or other means of measuring the level of bacterial activity, in both metalworking and associated fluids eg in washing machines, and act on the readings obtained in line with your risk assessment;
  • ensure that, as a minimum, a responsible person carries out the required health surveillance
  • conduct asthma health checks
  • refer anyone affected by exposure to a competent occupational health professional;
  • take prompt action after any diagnosis of ill health to identify the likely cause and ensure it is prevented or adequately controlled; and
  • keep workers informed of all findings.

For more information, visit the HSE web page: http://www.hse.gov.uk/metalworking/index.htm or contact us on 07896 016380 and we’ll be happy to help.

Contains public sector information published by the Health and Safety Executive and licensed under the Open Government Licence