Organic solvents are volatile organic compounds (VOCs), which are chemicals that easily vaporise at room temperature and may be harmful if inhaled. Metals production and processing businesses use solvents for a number of purposes including:
- chemical binding systems for making moulds
- cleaning recycled scrap metal before returning it to the furnace
- lubricants in die casting processes
- cleaning metals after casting, eg to remove oxides and greases
Check if you need a permit
If you use organic solvents, you may require a pollution prevention and control permit from the Northern Ireland Environment Agency (NIEA) or your local district council. If you have a permit you must comply with its conditions, which may require you to reduce or control your solvent emissions.
Prevent water pollution from solvents
You must not allow solvents to enter surface water drains, surface waters, the ground or groundwater. This causes pollution and you could be prosecuted.
If you intend to discharge solvents to the foul sewer, you must have an authorisation from NI Water.
ODS and F-gases in solvents
You must not use solvents containing ozone-depleting substances (ODS).
Solvents which contain fluorinated greenhouse gases (F-gases) that have a high potential to cause global warming are restricted. You must never allow F-gas solvents to vent directly to the air or be discharged directly into drains.
If you operate equipment that contains F-gas solvents you must ensure the solvents are recovered properly during servicing, maintenance and at the end of the equipment's life. This must be done by someone with the correct qualifications.
Good practice for solvent use
- keep solvent containers closed when you are not using them - this will minimise emissions evaporating into the atmosphere
- cover your solvent storage area to prevent weather conditions affecting your containers or containment systems
- check the condition of your solvent containers regularly
- locate, use and maintain solvent storage facilities as you would other chemical storage facilities
- ask your solvent supplier if they offer a solvent reclamation service - this can reduce the amount you spend on solvents
- review the solvents that you store and use on site regularly to determine if lower VOC alternatives can be used instead
- consider using water-based lubricants instead of solvent-based ones in metal casting processes