Biodiesel is produced from fat material of animal or plant origin, by means of chemical or physical processes. 

There are two ways of producing biodiesel using waste or virgin vegetable oil:

  • Chemical production, which makes use of one of a number of possible chemical reactions. The most frequently used is transesterification - where the fat material is heated, filtered and combined with an alcohol (usually methanol) and a catalyst. As a result this produces biodiesel and a by-product, glycerol.
  • Physical production, where the oil is heated to melt the fat and remove water. It is then filtered and blended with hydrocarbons to alter the cetane rating (how easily a fuel ignites and how fast it will burn).

The fat material used can be derived from vegetable sources, such as the plants Jatropha, Camelina and cotton, soybeans, rapeseed/ canola oil, sunflower oil, palm oil, peanut oil, walnut oil, avocado oil, algae oil, and others. In terms of fat materials derived from animal sources, these include animal fat, such as beef tallow, pork lard and chicken fat, and also fish oils.

Growing crops specifically for biodiesel has the disadvantage that it can take away fertile land that would otherwise be used to grow crops for food, and so, there has been a focus on biofuels made from resources that do not require use of agricultural land. These include agricultural waste (such as stems, leaves and husks), forestry residues, wood chips, sawdust, animal fats, food wastes (such as used cooking oils, restaurant leftover greases, etc), soapstocks and brown grease (fat and oil removed from grease traps and sewers).

Permits, licences and authorisations required

You may need a pollution prevention and control permit or waste management licence if you produce your own biodiesel. See the page in this guideline: Do you need a permit or licence to produce biofuel?

In Northern Ireland - Quality protocol for making biodiesel from waste cooking oil

The Environment Agency (EA), the Northern Ireland Environmental Agency (NIEA) and the Waste and Resources Action Programme (WRAP) have created a quality protocol for biodiesel produced from waste cooking oil and rendered animal fats. If you follow the protocol you can produce a high-quality biodiesel which you can sell without following waste management controls. For example, if it is not classed as a waste, you do not need to transport it using a waste carrier or with a waste transfer note, making it easier to sell your biodiesel.

GOV.UK: Biodiesel Quality Protocol

In Scotland - Animal by-products and waste oils allowed for making biofuels

Find out what animal by-products you may use to make biodiesel, whether you need approval, how to process them and how to use the products.

DEFRA and Animal and Plant Health Agency: Guidance for biodiesel producers - when you can use animal fat and cooking oil

Comply with oil storage regulations

You must store biofuels and all liquid wastes, such as used cooking oils, securely:

  • in containers that are strong enough and unlikely to burst or leak
  • within a suitable secondary containment system, e.g. a bund or drip tray, which must be able to contain any oil or fuel that escapes.

See our guide Oil Storage

You may also need a waste management licence to store waste cooking oil. See the page in this guideline: Do you need a permit or licence to produce biofuel?

Manage by-products correctly

If you manufacture biodiesel, you will produce glycerol as a by-product.

Contact your environmental regulator to find out if the glycerol you produce is classed as waste.

Contact your environmental regulator

If the glycerol you produce is waste, you must only send it to an Energy from Waste (EfW) plant (compliant with the Industrial Emissions Directive) to be burned. See our guideline: Waste incineration

If you dispose of glycerol, then you must also follow your duty of care for waste. See our guides:

Store and use hazardous chemicals safely

When producing biodiesel you will use potentially hazardous chemicals such as methanol, an organic solvent. Organic solvents are a type of volatile organic compound (VOC), which can cause significant air and water pollution, and land contamination, and are a fire and explosive hazard. You must not release methanol into the environment. If substantial quantities of methanol are released you should report the pollution incident as soon as it happens to the UK wide Pollution Hotline on Tel 0800 80 70 60.

See our guide Solvents emissions

If you make biodiesel for your own personal use, you should follow the advice from the Health & Safety Executive (HSE).

HSE: Domestic production of biodiesel – health and safety warning

Meet Control of Major Accident Hazards (COMAH) Regulations

If you store large quantities of dangerous substances, for example materials used to make biofuels, check whether the COMAH Regulations affect you. COMAH may also affect your site if you store fuels, including gases like biomethane, over certain thresholds.

You may need a major accident prevention policy, have to submit a safety report and prepare an on-site emergency plan.

See our guide COMAH

Quality standards for biofuels

You must meet quality standards to sell your fuel in countries of the European Union (EU). These standards apply to biofuel and blends containing biofuel. For example, the standard EN14214 specifies the requirements and test methods for biodiesel produced for use in diesel engines. See standards for biodiesel in the European Union: European Union Biofuel specifications (on

The European Committee for Standardization (CEN) promotes standards for the safety of workers and consumers and to protect the environment, in the European Union: European Committee for Standardization (CEN)

Further information

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