What drove operating margin change as of FY2022 for 3M? If operating margin is not a useful metric for a company like this, then please state that and explain why.
SG&A, measured as a percent of sales, increased in 2022 when compared to the same period last year. SG&A was impacted by increased special item costs for significant
litigation primarily related to steps toward resolving Combat Arms Earplugs litigation (discussed in Note 16) resulting in a 2022 second quarter pre-tax charge of approximately
$1.2 billion, certain impairment costs related to exiting PFAS manufacturing (see Note 15), costs related to exiting Russia (see Note 15), divestiture-related restructuring
charges (see Note 5), and continued investment in key growth initiatives. These increases were partially offset by restructuring benefits and ongoing general 3M cost
management.
Operating Margin for 3M in FY2022 has decreased by 1.7% primarily due to: 
-Decrease in gross Margin
-mostly one-off charges including Combat Arms Earplugs litigation, impairment related to exiting PFAS manufacturing, costs related to exiting Russia and divestiture-related restructuring
charges