Regulation 21 Application of regulations 22 and 23I1 Northern Ireland Regulations 22 and 23 apply below ground in mines in which places have been classified as hazardous under regulation 7(1) of DSEAR. Annotations Commencement I1 Reg. 21 in operation at 1.2.2017, see reg. 1(2) ← Regulation 20 Regulation 21 Regulation 22 →