There appears to be some confusion about the law relating to ionising radiation. I hope the following clarifies some of the points raised in previous posts.
The relevant law is the Ionising Radiation Regulations (IRRs17) which came into force in 2017. These replaced the previous regulations (IRRs99) which came into force in 1999. Both these regulations make no distinction between the effective dose limits which apply to men and women i.e. they are same for men and women in both regulations. A lower dose limit applies to workers below the age of 18. The regulations also mean that any person below the age of 16 should not receive an occupational dose.
There is an additional legal requirement in Reg 9(1) for the operator to reduce doses as far as reasonably practicable below the legal dose limit. This is known as the ALARP principle.
There is a further legal requirement in Reg 9(4)for the operator to introduce Dose Constraints, where appropriate. Dose Constraints are set at below the legal limit and are often developed during the design and planning stage. They represent the level of dose which should not be exceeded in a well-managed workplace, and are one of the methods for complying with the ALARP principle. Dose Constraints are typically used in certain applications in the nuclear industry. As the OP's DH works in the nuclear industry, the lower dose levels that he is referring to are presumably the Dose Constraints.
It follows from the above that compliance IRRs17 does not represent a relaxation in safety standards and will not attract potential law suits as has been suggested in other posts.
It is not true that classified workers have individual dose limits, they have individual dose assessments i.e. assessments of the actual dose received.
It is not true that the lower legal dose limit which applies to pregnant women is missing from IRRs17; it is covered in Reg 9(6). There is also a legal requirement
under Reg 15(1)c for the employer to inform female workers (for example by training and instructions) about the risk of ionising radiation to the foetus, and the importance of informing the employer in writing as early as possible once a woman has discovered she is pregnant. This is so the employer can implement any necessary measures to reduced to any dose below the legal limit applying to pregnant women and to comply with the ALARP principle. Provided that the employer complies with the information requirements in Reg 15(1)c, I fail to see how the employer could be held responsible for any over-exposure which might arise from deliberate non-disclosure of pregnancy.
The disclosure of pregnancy by the woman is voluntary (not a legal requirement). Its worth pointing out that there is a requirement in the IRRs, and in health and safety law more generally, that an employee should cooperate with the employer in compliance with the law. The employer is not solely responsible for safe working practices; the employee has some responsibility for their own safety and the safety of others.
I hope this clarifies the law in this area.