## Critical accounting policies 

Our consolidated financial statements are prepared in conformity with U.S generally accepted accounting principles. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses. We have described our accounting policies in Note 1 to our consolidated financial statements included in this Form 10-K. We have reviewed these accounting policies, identifying those that we believe to be critical to the preparation and understanding of our consolidated financial statements. We have reviewed with the Audit Committee those accounting policies that we have deemed critical. These policies are central to our presentation of results of operations and financial condition and require management to make estimates and judgments on certain matters. We base our estimates and judgments on historical experience, current conditions and other reasonable factors. 

## Environmental obligations 

We provide for environmental-related obligations when they are probable and amounts can be reasonably estimated. Where the available information is sufficient to estimate the amount of liability, that estimate has been used. Where the information is only sufficient to establish a range of probable liability and no point within the range is more likely than any other, the lower end of the range has been used. 

Estimated obligations to remediate sites that involve oversight by the United States Environmental Protection Agency (“EPA”), or similar government agencies, are generally accrued no later than when a Record of Decision (“ROD”), or equivalent, is issued, or upon completion of a Remedial Investigation/Feasibility Study (“RI/FS”), or equivalent, that is submitted by us to the appropriate government agency or agencies. Estimates are reviewed quarterly by our environmental remediation management, as well as by financial and legal management and, if necessary, adjusted as additional information becomes available. The estimates can change substantially as additional information becomes available regarding the nature or extent of site contamination, required remediation methods, and other actions by or against governmental agencies or private parties. 

Our environmental liabilities for continuing and discontinued operations are principally for costs associated with the remediation and/or study of sites at which we are alleged to have released hazardous substances into the environment. Such costs principally include, among other items, RI/FS, site remediation, costs of operation and maintenance of the remediation plan, fees to outside law firms and consultants for work related to the environmental effort, and future monitoring costs. Estimated site liabilities are determined based upon existing remediation laws and technologies, specific site consultants’ engineering studies or by extrapolating experience with environmental issues at comparable sites. 

Included in the environmental reserve balance, other assets balance and disclosure of reasonably possible loss contingencies are amounts from third party insurance policies, which we believe are probable of recovery. 

Provisions for environmental costs are reflected in income, net of probable and estimable recoveries from named Potentially Responsible Parties (“PRPs”) or other third parties. Such provisions incorporate inflation and are not discounted to their present values. 

In calculating and evaluating the adequacy of our environmental reserves, we have taken into account the joint and several liability imposed by Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) and the analogous state laws on all PRPs and have 

considered the identity and financial condition of the other PRPs at each site to the extent possible. We have also considered the identity and financial condition of other third parties from whom recovery is anticipated, as well as the status of our claims against such parties. Although we are unable to forecast the ultimate contributions of PRPs and other third parties with absolute certainty, the degree of uncertainty with respect to each party is taken into account when determining the environmental reserve by adjusting the reserve to reflect the facts and circumstances on a site-by-site basis. Our liability includes our best estimate of the costs expected to be paid before the consideration of any potential recoveries from third parties. We believe that any recorded recoveries related to PRPs are realizable in all material respects. Recoveries are recorded as either an offset in “Environmental liabilities, continuing and discontinued” or as “Other Assets” in our consolidated balance sheets in accordance with U.S. accounting literature. 

See Note 10 to our consolidated financial statements included in this Form 10-K for changes in estimates associated with our environmental obligations. 

## Impairments and valuation of long-lived assets 

Our long-lived assets include property, plant and equipment and long-term investments, goodwill and intangible assets. We test for impairment whenever events or circumstances indicate that the net book value of these assets may not be recoverable from the estimated undiscounted expected future cash flows expected to result from their use and eventual disposition. In cases where the estimated undiscounted expected future cash flows are less than net book value, an impairment loss is recognized equal to the amount by which the net book value exceeds the estimated fair value of assets, which is based on discounted cash flows at the lowest level determinable. The estimated cash flows reflect our assumptions about selling prices, volumes, costs and market conditions over a reasonable period of time. 

We perform an annual impairment test of goodwill in the third quarter. The assumptions used to estimate fair value include our best estimate of future growth rates, discount rates and market conditions over a reasonable period. We performed this test in 2010 and determined that no impairment charge was required. 

See Note 7 to our consolidated financial statements included in this Form 10-K for charges associated with long-lived asset disposal costs and the activity associated with the restructuring reserves. 

## Pensions and other postretirement benefits 

We provide qualified and nonqualified defined benefit and defined contribution pension plans, as well as postretirement health care and life insurance benefit plans to our employees and retirees. The costs (benefits) and obligations related to these benefits reflect key assumptions related to general economic conditions, including interest (discount) rates, healthcare cost trend rates, expected rates of return on plan assets and the rates of compensation increases for employees. The costs (benefits) and obligations for these benefit programs are also affected by other assumptions, such as average retirement age, mortality, employee turnover, and plan participation. To the extent our plans’ actual experience, as influenced by changing economic and financial market conditions or by changes to our own plans’ demographics, differs from these assumptions, the costs and obligations for providing these benefits, as well as the plans’ funding requirements, could increase or decrease. When actual results differ from our assumptions, the 

