40 C.F.R. § 14.4
EPA does not insure its employees from every loss or damage to personal property they may sustain. In order for a claim to be allowed, the item must not only have been incident to service, it must also have been reasonable and proper for the employee to possess the item at the time and place of its loss or damage. Generally, the possession of an item is reasonable and proper when the item is of a type and quantity which EPA reasonably expected its employees to possess at the time and place of the loss or damage. Consequently, items which are exceptionally expensive, excessive quantities of otherwise allowable items, personal items which are used in place of items usually provided to employees by EPA or items which are primarily of aesthetic value are not considered reasonable or proper items and are unallowable.
40 C.F.R. § 14.4