McDonald's to recycle cooking oil for fuel

"As we get better at the refinement we will be able to remove virgin rape (oil) from the process," Howe said.

Howe said the company keeps its used cooking oil apart from other supplies.

HEALTHIER OILS

"We have ensured we don't have any other oils. A lot of other cooking oils that are collected are very contaminated," he said, noting animal fats can cause refining difficulties.

McDonald's UK is using a mixture of high oleic UK rapeseed oil and sunflower oil from Spain to fry its food. The company switched to the formula in April as part of its strategy to stop using hydrogenated fats.

Hydrogenation can lead to the creation of trans fats which may have worse effects on the human body than saturated fats, according to Britain's Food Standards Agency.

High oleic oils are designed to replicate the stability and long shelf life of hydrogenated oils without the adverse health impacts.

Howe said the company had been using all UK-grown rapeseed oil prior to the switch but now had to rely partly on imported sunflower oil supplies.

British farmers have begun to plant high oleic varieties of rapeseed but supplies are still very tight with imported high oleic sunflower oil much more readily available.