WAC 296-127-400 through 296-127-470 are issued pursuant to RCW 39.12.022, authorizing the director of the department of labor and industries, to the extent necessary in order to prevent curtailment of opportunities for employment, to issue special subprevailing wage certificates for employment of individuals whose earning capacity is impaired by physical or mental disability or injury at wages lower than the prevailing rate applicable under RCW 39.12.020. Subprevailing wage certificates shall be subject to the conditions prescribed in these regulations.