Company’s pension and postretirement obligations, and asset impairments. Senior management has discussed the development, selection and disclosure of its critical accounting estimates with the Audit Committee of 3M’s Board of Directors.

Legal Proceedings:

The categories of claims for which the Company has estimated its probable liability, the amount of its liability accruals, and the estimates of its related insurance receivables are critical accounting estimates related to legal proceedings. Please refer to the section entitled “Accrued Liabilities and Insurance Receivables Related to Legal Proceedings” (contained in “Legal Proceedings” in Note 13) for additional information about such estimates.

Pension and Postretirement Obligations:

3M has various company-sponsored retirement plans covering substantially all U.S. employees and many employees outside the United States. The Company accounts for its defined benefit pension and postretirement health care and life insurance benefit plans in accordance with Statement of Financial Accounting Standards (SFAS) No. 87, “Employers’ Accounting for Pensions,” SFAS No. 106, “Employer’s Accounting for Postretirement Benefits Other than Pensions,” in measuring plan assets and benefit obligations and in determining the amount of net periodic benefit cost, and SFAS No. 158, “Employer’s Accounting for Defined Benefit Pension and Other Postretirement Benefit Plans an amendment of FASB Statements No. 87, 88, 106 and 132(R),” which was issued in September 2006 and effective as of December 31, 2006. SFAS No. 158 requires employers to recognize the underfunded or overfunded status of a defined benefit postretirement plan as an asset or liability in its statement of financial position and recognize changes in the funded status in the year in which the changes occur through accumulated other comprehensive income, which is a component of stockholders’ equity. As a result of the implementation of SFAS No. 158, the Company recognized an after-tax decrease in accumulated other comprehensive income of $1.187 billion and $513 million for the U.S. and International pension benefit plans, respectively, and $218 million for the postretirement health care and life insurance benefit plan.

Pension benefits associated with these plans are generally based primarily on each participant’s years of service, compensation, and age at retirement or termination. Two critical assumptions, the discount rate and the expected return on plan assets, are important elements of expense and liability measurement. The assumed health care trend rate is the most significant postretirement health care assumption. See Note 11 for additional discussion of actuarial assumptions used in determining pension and postretirement health care liabilities and expenses.

The Company determines the discount rate used to measure plan liabilities as of the December 31 measurement date for the U.S. pension and postretirement benefit plans. The discount rate reflects the current rate at which the associated liabilities could be effectively settled at the end of the year. In estimating this rate, the Company looks at rates of return on fixed-income