reg 20 Reference levels
(1) The operator or local authority which has prepared an emergency plan in accordance with regulations 10 or 11, as the case may be, must ensure that the emergency plan prioritises keeping effective doses below a 100 mSv reference level. (2) The operator or local authority must record in the emergency plan for which it is responsible the appropriate dose level for each emergency worker as determined by the employer in accordance with regulation 18(2). (3) Where the response to a radiation emergency is underway, reference levels determined for emergency workers in accordance with regulation 18(2) may be revised or introduced in relation to specific tasks by that emergency worker's employer in order to optimise the response. (4) In exceptional circumstances, in order to save life, to prevent severe radiation-induced health effects or to prevent the development of catastrophic conditions, a reference level for an effective dose for an emergency worker from external ionising radiation may be set by an employer in excess of 100 mSv but not exceeding 500 mSv. (5) Where the response to a radiation emergency is underway, specific reference levels, to optimise the response, may be determined by the local authority in whose area an off-site emergency plan is in place. (6) In determining specific reference levels under paragraph (5), the local authority must take advice from the person coordinating the off-site response to the radiation emergency. (7) The Secretary of State may also set a reference level whether applicable locally or nationally in addition to any reference level set under paragraph (5). (8) Any revision of the reference levels in response to a radiation emergency made in accordance with paragraph (3), (4), (5) or (7) must be recorded in the report required by regulation 17(6).