cost of goods sold. Our warranty reserve requirements changed during fiscal 2012 as follows: Balance as of September 30, 2011 Reserve for product warranty during the reporting period Settlement of warranty Balance as of September 30, 2012 $ 384 867 (892) $ 359 as a capital lease for accounting purposes and the present value of the minimum quarterly payments resulted in an initial $9,776 lease obligation and related leased asset. The agreement expired in December 2011. Future minimum rental commitments under noncancelable leases as of September 30, 2012 are as follows: Fiscal Year 2013 2014 2015 2016 2017 Thereafter Amount related to interest Capital lease obligation Operating $2,830 2,179 1,116 1,013 785 520 $8,443 Capital $ 2 5 5 5 4 — 21 — $21 Indemnification In the normal course of business, we are a party to a variety of agreements pursuant to which we may be obligated to indemnify the other party with respect to certain matters. Generally, these obligations arise in the context of agreements entered into by us, under which we customarily agree to hold the other party harmless against losses arising from items such as a breach of certain representations and covenants including title to assets sold, certain intellectual property rights and certain environmental matters. These terms are common in the industries in which we conduct business. In each of these circumstances, payment by us is subject to certain monetary and other limitations and is conditioned on the other party making an adverse claim pursuant to the procedures specified in the particular agreement, which typically allow us to challenge the other party’s claims. We evaluate estimated losses for such indemnifications under the accounting standards related to contingencies and guarantees. We consider such factors as the degree of probability of an unfavorable outcome and the ability to make a reasonable estimate of the amount of loss. To date, we have not experienced material costs as a result of such obligations and, as of September 30, 2012, have not recorded any liabilities related to such indemnifications in our financial statements as we do not believe the likelihood of such obligations is probable. Purchase Obligations Purchase obligations include our take-or-pay arrangements with suppliers, and purchase orders and other obligations entered into in the normal course of business regarding the purchase of goods and services. We purchase fumed silica primarily under a fumed silica supply agreement with Cabot Corporation, our former parent company that is not a related party, that became effective in January 2004, and was amended in September 2006 and in April 2008, the latter of which extended the termination date of the agreement from December 2009 to December 2012 and also changed the pricing and some other non-material terms of the agreement to the benefit of both parties. We are generally obligated to purchase fumed silica for at least 90% of our six-month volume forecast for certain of our slurry products, to purchase certain minimum quantities every six months, and to pay for the shortfall if we purchase less than these amounts. We are currently working with Cabot Corporation to negotiate the terms of a new fumed silica supply agreement that we anticipate would take effect following the expiration of the current agreement. Since December 2001, we have purchased fumed alumina primarily under a fumed alumina supply agreement with Cabot Corporation that expired in December 2011. We are now operating under a renewed fumed alumina supply agreement with Cabot Corporation, which expires in April 2013, under which we are obligated to pay certain fixed, capital and variable costs, and have certain take-or-pay obligations, We currently anticipate we will not have to pay any shortfall under these agreements. Purchase obligations include $8,994 of contractual commitments for fumed silica and fumed alumina under these contracts. Lease Commitments We lease certain vehicles, warehouse facilities, office space, machinery and equipment under cancelable and noncancelable leases, all of which expire within six years from now and may be renewed by us. Lease commitments also include certain costs associated with our pad finishing operation located at Taiwan Semiconductor Manufacturing Company, which are accounted for as an operating lease. Rent expense under such arrangements during fiscal 2012, 2011 and 2010 totaled $3,199, $2,934 and $2,480, respectively. In December 2001 we entered into a fumed alumina supply agreement with Cabot Corporation under which we agreed to pay Cabot Corporation for the expansion of a fumed alumina manufacturing facility in Tuscola, Illinois. The arrangement for the facility has been treated 57