No policies shall be issued by any such association until members in such numbers and with such numbers of employees as the Insurance Commissioner may decide will give a fair diffusion of risks have obligated themselves to take policies immediately upon their authorization, nor shall any policies be issued except such as the Insurance Commissioner has approved as conforming in all respects to the requirements of this chapter. In conformance with the provisions of section 31-284, policies may be issued covering claims only in excess of a certain amount. If, at any time, by the retirement of members, reduction of numbers of employees or other cause, the membership of any association appears to the Insurance Commissioner no longer to afford a fair diffusion of risks, he may suspend or forbid the further issue of policies until the former conditions of the association have been restored.