(1) Fringe benefits are allowances and services provided by the contractor to its employees as compensation in addition to regular wages and salaries. Fringe benefits include, but are not limited to, the cost of vacations, sick leave, holidays, military leave, employee insurance, and supplemental unemployment benefit plans. Except as provided otherwise in subpart  31.2, the costs of fringe benefits are allowable to the extent that they are reasonable and are required by law, employer-employee agreement, or an established policy of the contractor.