Your business may use solvents to remove grease and oil. You can apply solvents using rags, vapour or immersion degreasing baths.

If your business carries out vapour degreasing you will use halogenated solvents, including:

  • trichloroethylene (trike)
  • methylene chloride (dichloromethane)
  • n-propyl bromide (stabilised)
  • perchloroethylene (perc).

Organic solvents can have a significant impact on human health and air quality. You should try to find the most eco friendly degreaser. A number of products can be bought that don't rely on chlorinated or fluorinated compounds, and which have far fewer environmental or health impacts.

What you must do

Check if you need a permit, licence or exemption

If you use degreasing solvents you may need a pollution, prevention and control permit.

If you have a permit, licence or exemption you must comply with its conditions, including any conditions about solvent emissions or other emissions.

Do not use ozone depleting substances

You must not use ozone depleting substances (ODS) for most degreasing or solvent applications, including:

  • hydrochlorofluorocarbons (HCFCs)
  • chlorofluorocarbons (CFCs)
  • 1,1,1 trichloroethane
  • bromochloromethane (CBM)
  • carbon tetrachloride.

Some vapour degreasing baths use banks of refrigerant-filled coils in the condensing zone. If your equipment still contains CFCs, HCFCs or halon-based refrigeration systems, you must make sure that your staff or contractors who service and repair refrigeration equipment comply with the controls on ozone depleting substances (ODS). Most ODS have been phased out but may still remain in older equipment.

Comply with your waste responsibilities

You must comply with your duty of care responsibilities when dealing with waste.

You may need to deal with the following materials and substances as hazardous/special waste:

  • degreasing solvents
  • sump contamination (still bottoms)
  • soiled, solvent-impregnated rags
  • used containers
  • water collected in water and solvent separators.

For further information, see our guidance on hazardous/special waste.

Check if you need any permits, consents or other authorisations to discharge water

Do not discharge to public sewers, surface waters or groundwater without consulting your regulator. You may need a discharge consent, groundwater authorisation or other authorisation. For further information, see our guidance on discharges to water and sewer.

Good practice

Use less hazardous products and techniques

Trike and n-propyl bromide are classified as category two carcinogens. If you use these substances you should try to replace them with a less harmful alternative. You may be required to do this as a condition of your permit or by health and safety laws.

European trike producers have signed a voluntary agreement on the safe use of trike in metal cleaning. Trike will not be supplied for metal cleaning or degreasing unless the user has a closed system.

Health and Safety Executive (HSE): Solvent vapour degreasing plant

European Chlorinated Solvent Association: Closed equipment technology for metal degreasing with trichloroethylene

Reduce your solvent use and losses

  • Choose a closed-top system, or interlocking system if appropriate, when you replace your equipment as it will reduce your solvent consumption and energy use.
  • Locate your vapour degreasing machines away from draughts from doors, windows and heating to avoid excessive solvent loss.
  • Remove components from your degreasing baths slowly and under control. This will reduce solvent loss.
  • Put lids on your solvent containers when you are not using them to reduce solvent loss.
  • Consider fitting lids to any open-top degreasing baths. Fit your lids in the free-board zone.
  • Control your lip extraction rates to ensure your staff are safe and to prevent excessive loss of solvent.
  • Service and maintain your equipment regularly, and pay particular attention to refrigeration and extraction systems.
  • Use 'squeeze' type bottles for transferring solvent onto rags.

Manage your solvent waste and prevent contamination

  • Do not mix different waste solvents as this could be dangerous and prevent your solvents from being reclaimed.
  • Consider laundering and reusing the rags you use for surface cleaning.
  • Monitor the boiling temperature of your vapour degreasing bath. Heavily contaminated solvents have higher boiling points. This indicates that you need to change your solvent.
  • Fill your degreasing systems from fixed pipework lines to reduce the risk of spills and land contamination.
  • Check the degreasing system for leaks and corrosion regularly.

Further information on degreasing solvents

Envirowise: Cost effective solvent management (Adobe PDF - 548KB)


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