W. Va. Code R. § 85-18-7
In addition to all other security required to be posted for the purpose of maintaining self-insured status under this rule and 85 CSR 19, the Commissioner may require self-insured employers to post an additional amount of security, procure a policy of excess insurance, or both, for the purpose of covering potential catastrophic occurrences. Whether a self-insured employer is required to post security and/or maintain a policy of excess insurance pursuant to this section, and, if so, the amount of security and/or excess insurance required, shall be determined by the application of objective criteria by the Commissioner which will be used to determine the need for additional financial protection against catastrophic risks. Any policy of excess insurance or security required in this section shall be in a form approved by the Commissioner. The self-insured retention amount of any excess policy as described in this section shall be subject to the approval of the Commissioner.
W. Va. Code R. § 85-18-7