Since 1.10.86, you can get benefit only if your total disablement is assessed at 14% or more, or at least 1% for pneumoconiosis and byssinosis. For information on the lump-sum gratuities that were available on assessments of 1-19% before 1.10.86, see Disability Rights Handbook, 43rd edition, page 279.

Benefit is paid as a weekly pension. Assessments of 14-19% disablement are paid at the 20% rate. Assessments of 24% (or 44%, etc) are rounded down and paid at the 20% rate (or 40%, etc). Assessments of 25% (or 45%, etc) are rounded up and paid at the 30% rate (or 50%, etc). For pneumoconiosis and byssinosis, assessments of 1-10% are paid at the 10% rate (ie £23.39) and assessments of 11-24% are paid at the 20% rate.
SSCBA, S.103(3) ; IIPD Regs , regs 15B & 20(1)-(1A)

Disablement assessments for more than one industrial injury