http://www.legislation.gov.uk/id/nisr/1998/28/schedule/1/part/6/crossheading/tar-and-bitumen-processes

SCHEDULE 1DESCRIPTIONS OF PROCESSES

Chapter 6Other Industries

Section 6.3Tar and bitumen processes

Part A

Any process not falling within any other description in this Schedule involving—

a

the distillation of tar or bitumen in connection with any process of manufacture; or

b

the heating of tar or bitumen for the manufacture of electrodes or carbon-based refractory materials, where the carrying on of the process by the person concerned at the location in question is likely to involve the use in any 12 month period of 5 tonnes or more of tar or of bitumen or, in aggregate, of both.