Schedule 2

SECOND SCHEDULERegulations 16(15), 30(1), (6) and (7), 35(8), 47(3), 51, 68(4) and (5) and 71(1)Part 1Dose Limits For OCCUPATIONAL EXPOSURE1. Except as provided in paragraph 6, the dose limits for occupational exposure of workers above 18 years of age are those specified in the following table:ApplicationDose limit per year(mSv)Effective dose (whole body)20Equivalent dose to the lens of the eye20 the skin500 the hands and feet500Notes:1.The limit on effective dose (whole body) is 20 mSv per year, averaged over 5 consecutive years and with the further provision that the effective dose does not exceed 50 mSv in any single year. The limit applies to the sum of the relevant doses from external exposure in the specified period and the committed effective dose.2.The limit on equivalent dose to the lens of the eye is 20 mSv per year, averaged over 5 consecutive years and with the further provision that the equivalent dose does not exceed 50 mSv in any single year.3.The equivalent dose limit for the skin applies to the average dose over 1 cm2 of the most highly irradiated area of the skin.

2. Except as provided in paragraph 6, the dose limits for apprentices of 16 to 18 years of age who are being trained for employment involving radiation and for exposure of students of 16 to 18 years of age who use sources in the course of their studies are those specified in the following table:ApplicationDose limit per year(mSv)Effective dose (whole body)6Equivalent dose to the lens of the eye20 the skin150 the hands and feet150Note:1.The equivalent dose limit for the skin applies to the average dose over 1 cm2 of the most highly irradiated area of the skin.

3. For the purposes of this Part, the dose from any medical or dental exposure as a patient, from the exposure to natural background radiation or from other exposures received by the worker as a member of the public are not to be taken into account.

4. Where only a part or parts of a human body are irradiated by external radiation, the effective dose received from external radiation is determined by calculating the sum of wTHT over all the organs and tissues irradiated, where —

5. The values of the tissue weighting factors to be used for determining the weighted equivalent dose wTHT, are those specified in the following table:Tissue or organTissue weighting factor wTBone marrow (red)0.12Colon0.12Lung0.12Stomach0.12Breast0.12Gonads0.08Bladder0.04Liver0.04Oesophagus0.04Thyroid0.04Skin0.01Bone surface0.01Brain0.01Salivary gland0.01Remainder0.12Note:1.The wT for remainder tissues (0.12) applies to the arithmetic mean dose to these 13 tissues and organs for each sex: adrenals, extrathoracic region, gall bladder, heart, kidneys, lymphatic nodes, muscle, oral mucosa, pancreas, prostate (male), small intestines, spleen, thymus, uterus/cervix (female).

6. Upon notification by a female worker of her suspected pregnancy or that she is breastfeeding, the employer of the female worker must adapt her working conditions in respect of occupational exposure so as to ensure that the embryo or foetus or the breastfed infant is afforded the same broad level of protection as is required for members of the public.Part 2Dose Limits For Individual Members Of The Public

1. The annual dose limits for individual members of the public are those specified in the following table:ApplicationDose limit per year (mSv)Effective dose (whole body)1Equivalent dose to the lens of the eye15 the skin50Notes:1.In special circumstances, a higher value of effective dose for the whole body could be allowed in a single year, provided that the average effective dose over 5 consecutive years does not exceed 1 mSv per year. The limit applies to the sum of the relevant doses from external exposure in the specified period and the committed effective dose.2.The equivalent dose limit for the skin applies to the average dose over 1 cm2 of the most highly irradiated area of the skin.

2. For the purposes of this Part, the dose from any medical or dental exposure as a patient or from the exposure to natural background radiation are not to be taken into account.Part 3Values Of Radiation Weighting Factor For Different Types Of Ionising Radiation

1. The values of radiation weighting factor to be used in determining the equivalent dose in a tissue or organ are those specified in the following table:Type of ionising radiation and energy rangeRadiation weighting factorPhotons, all energies1Electrons and muons, all energies1Neutrons, energy < 10 keV5 10 keV to 100 keV10 > 100 keV to 2 MeV20 > 2 MeV to 20 MeV10 > 20 MeV5Protons, other than recoil protons, energy > 2 MeV5Alpha particles, fission fragments, heavy nuclei

202. For the purposes of this Part, all the specified values relate to the radiation incident on the body or, for internal sources, emitted from the source.Part 4GUIDANCE VALUES FOR RESTRICTING EXPOSURE OF EMERGENCY WORKERSTasksGuidance value (mSv)Life‑saving actionsHp(10) < 500Actions to prevent severe deterministic effects and actions to prevent the development of catastrophic conditions that could significantly affect people and the environmentHp(10) < 500Actions to avert a large collective doseHp(10) < 100Notes:1.The guidance values in the second column apply only for the dose from external exposure to strongly penetrating radiation. Doses from external exposure to weakly penetrating radiation and from intake or skin contamination need to be prevented by all possible means. If this is not feasible, the effective dose and the equivalent dose to a tissue or organ that are received must be limited to minimise the health risk to the individual in line with the risk associated with the guidance values here.2.The value relating to life‑saving actions can be exceeded under circumstances in which the expected benefits to others clearly outweigh the emergency worker’s own health risk, and the emergency worker volunteers to take the action and understand and accepts these health risks.3.Hp(10) in the second column is the personal dose equivalent Hp(d) where d = 10 mm.