Contingencies

Fuel Tech issues a standard product warranty with the sale of its products to customers. Our recognition of warranty liability is based primarily on analyses of warranty claims experienced in the preceding years as the nature of our historical product sales for which we offer a warranty are substantially unchanged. This approach provides an aggregate warranty accrual that is historically aligned with actual warranty claims experienced.

Changes in the warranty liability for the three months March 31, 2016, and 2015, are summarized below:



	Three Months Ended March 31,
	2016			2015
Aggregate product warranty liability at beginning of period	$	268		$	268
Net aggregate expense (benefit) related to product warranties	(109		)	2
Aggregate reductions for payments	—			(2		)
Aggregate product warranty liability at end of period	$	159		$	268