(1) If an employer is liable independently of this Act for damages for an occupational disease contracted by a worker, the following provisions have effect for the purposes of any policy of insurance obtained by the employer--(a) the liability is taken to have arisen when the worker was last employed by the employer in employment to the nature of which the disease was due, subject to paragraph (b),(b) if the worker was employed by the employer in employment to the nature of which the disease was due both before and after the relevant commencement, the liability is taken to have arisen both when the worker was last employed by the employer in employment to the nature of which the disease was due before the relevant commencement and when the worker was last employed by the employer in employment to the nature of which the disease was due after the relevant commencement.
(2) In a case in which subsection (1) (b) applies, 2 insurers will be liable under policies of insurance to indemnify the employer (or pay damages to the worker) and the following provisions apply with respect to those insurers (referred to in this subsection as the
"responsible insurers" )--(a) Of the responsible insurers, the one that is the insurer in respect of the employer's liability that arose after the relevant commencement is to be the insurer
"primarily responsible" for the claim.(b) The responsible insurers can however agree as to which of them is to be primarily responsible for the claim or the court can order that one of them is to be the insurer primarily responsible, and any such agreement or order overrides paragraph (a).(c) The insurer who is primarily responsible for the claim is to act for both the responsible insurers in respect of any claim for the damages and has sole liability for the claim (that is, it is to indemnify the employer for the full amount of the damages or is to pay the full amount of damages to the worker, without any right to a contribution from any other insurer, except as provided by paragraph (d)).(d) The insurer who is primarily responsible is entitled to recover from the other responsible insurer half of the amount paid as damages to the worker, half of the amount paid in respect of the worker's legal costs and half of such reasonable amount as the insurer primarily responsible may have incurred in respect of its own legal expenses in the matter.
(3) If 2 or more employers are jointly or severally liable for damages referred to in this section, the provisions of this section apply separately to each employer.
(4) This section does not affect the amount of damages recoverable by a worker.
(5) This section applies to any liability arising before or after the commencement of this Act and to any policy of insurance issued before or after that commencement.
(6) In sections 151AB and 151AC--
"occupational disease" means a disease of such a nature as to be contracted by a gradual process, and includes--(a) a dust disease as defined by the Workers' Compensation (Dust Diseases) Act 1942 , and(b) total or partial loss of sight which is of gradual onset, and(c) the condition known as "boilermaker's deafness" or any deafness of similar origin.
"relevant commencement" means--(a) except as provided by paragraph (b)--4 pm on 30 June 1987, or(b) in the case of an employer who was insured under a policy of insurance that was assigned as referred to in clause 10 of Part 15 of Schedule 6 to this Act--the commencement of the period of insurance of the policy so assigned.