We are confident in our ability to continue executing well in the face of COVID-19 uncertainties and are raising our full-year guidance for organic growth to 6% to 9%, and earnings per share to $9.70 to $10.10.
In the second quarter, we delivered total sales of $8.9 billion.
We posted organic growth of 21% versus a 13% decline in last year's second quarter, along with earnings of $2.59 per share.
We expanded adjusted EBITDA margins to over 27% and increased adjusted free cash flow to $1.6 billion with a conversion rate of 103%.
Strong cash flow allowed us to further strengthen our balance sheet while returning $1.4 billion to shareholders through dividends and share repurchases.
In home improvement, we are building out a suite of innovations to help consumers personalize their homes, including our fast-growing line of command damage-free hanging solutions, $500 million franchise that leverages our world-class adhesive platform with even greater opportunities ahead.
Since the onset of the pandemic, we have increased our annual respirator production fourfold to $2.5 billion by activating idle surge capacity and building additional lines, while shifting 90% of distribution into healthcare to protect nurses, doctors and first responders.
Companywide second-quarter sales were $8.9 billion, up 25% year on year or an increase of 21% on an organic basis.
Sales growth, combined with operating rigor and disciplined cost management, drove adjusted operating income of $2 billion, up 40%, with adjusted operating margins of 22%, up 240 basis points year on year.
Second-quarter GAAP and adjusted earnings per share were $2.59, up 44% compared to last year's adjusted results.
A strong year-on-year organic volume growth, along with ongoing productivity, restructuring efforts and other items, added 4.1 percentage points to operating margins and $0.89 to earnings per share year on year.
This favorable ruling added $91 million to operating income of 1 percentage point to operating margins and $0.12 to earnings per share.
Next, as you will see later today in our 10-Q, we increased our other environmental liability by nearly $60 million and our respiratory liabilities by approximately $20 million as part of our regular review.
And finally, during the second quarter, we incurred a pre-tax restructuring charge of approximately $40 million as part of the program we announced in Q4 of last year.
Second-quarter net selling price and raw materials performance reduced both operating margins and earnings per share by 140 basis points and $0.17, respectively.
As a result of these increasing cost trends, we now forecast a full-year raw materials and logistics cost headwind in the range of $0.65 to $0.80 per share versus a prior expectation of $0.30 to $0.50.
However, given the pace of cost increases, we currently expect a third-quarter net selling price and raw materials headwind to margins in the range of 50 to 100 basis points, which we anticipate will turn to a net benefit in the fourth quarter as our selling price and other actions start catching up to the increased costs.
The lost income from the sale of drug delivery in May of last year was a headwind of 10 basis points to operating margins and $0.02 to earnings per share.
Foreign currency, net of hedging impacts, reduced margins 20 basis points while benefiting earnings by $0.08 per share.
This result included a $0.06 earnings benefit from lower other expenses, that was offset by higher tax rate and diluted share count, which were each a headwind of $0.03 per share versus last year.
We delivered another quarter of robust free cash flow with second-quarter adjusted free cash flow of $1.6 billion, up 2% year on year, along with conversion of 103%.
Our year-on-year free cash flow performance was driven by strong double-digit growth in sales and income, which was mostly offset by a timing of an income tax payment of approximately $400 million in last year's Q3, which is traditionally paid in Q2.
Through the first half of the year, we increased adjusted free cash flow to $3 billion versus $2.5 billion last year.
Second-quarter capital expenditures were $394 million and approximately $700 million year to date.
For the full year, we are currently tracking to the low end of our expected capex range of $1.8 billion to $2 billion, given vendor constraints and the pace of capital projects.
During the quarter, we returned $1.4 billion to shareholders through the combination of cash dividends of $858 million and share repurchases of $503 million.
Year to date, we have returned $2.5 billion to shareholders in the form of dividends and share repurchases.
We ended the quarter with $12.7 billion in net debt, a reduction of $3.5 billion since the end of Q2 last year.
As a result, our net debt-to-EBITDA ratio has declined from 1.9 a year ago to 1.3 at the end of Q2.
I will start with our safety and industrial business, which posted organic growth of 18% year on year in the second quarter, driven by improving industrial manufacturing activity and prior pandemic impacts.
Within our respiratory portfolio, second-quarter disposable respirator sales increased 3% year on year but declined 11% sequentially as COVID-related hospitalizations declined.
Safety and industrial's second-quarter operating income was $718 million, up 15% versus last year.
Operating margins were 22.1%, down 130 basis points year on year as leverage on sales growth was more than offset by increases in raw materials, logistics and ongoing legal costs.
Moving to transportation and electronics, which grew 24% organically despite sustained challenges from semiconductor supply chain constraints.
Organic growth was led by our auto OEM business, up 76% year on year, compared to a 49% increase in global car and light truck builds.
Second-quarter operating income was $546 million, up over 50% year on year.
Operating margins were 22%, up 340 basis points year on year, driven by strong leverage on sales growth, which was partially offset by increases in raw materials and logistic costs.
Turning to our healthcare business, which delivered second-quarter organic sales growth of 23%.
Our medical solutions business grew mid-teens organically or up approximately 20%, excluding the decline in disposable respirator demand.
I am pleased with the performance of Acelity, which grew nearly 20% organically in the quarter as it helps us build on our leadership in Advanced Wound Care.
The separation and purification business increased 10% year on year due to ongoing demand for biopharma filtration solutions for COVID-related vaccine and therapeutics, along with improving demand for water filtration solutions.
Health care's second-quarter operating income was $576 million, up over 90% year on year.
Operating margins were 25.3%, up 880 basis points.
Lastly, second-quarter organic growth for our consumer business was 18% year on year with strong sell-in and sell-out trends across most retail channels.
Consumer's operating income was $311 million, up 12% year on year.
Operating margins were 21%, down 160 basis points as increased costs for raw materials, logistics and outsourced hard goods manufacturing, along with investments in advertising and merchandising more than offset leverage from sales growth.
As mentioned earlier, we expect demand for disposable respirators to wane and negatively impact second-half revenues by approximately $100 million to $300 million year on year.
As noted, we anticipate a year-on-year earnings headwind of $0.65 to $0.80 per share for the full year or $0.40 to $0.55 in the second half due to rising cost pressures.
As part of this program, we expect to incur a pre-tax charge in the range of $60 million to $110 million in the second half of this year.
Organic growth is estimated to be 6% to 9%, up from the previous range of 3% to 6%.
We now anticipate earnings of $9.70 to $10.10 per share against a prior range of $9.20 to $9.70.
Also, as you can see, we now expect free cash flow conversion in the range of 90% to 100% versus a prior range of 95% to 105%.
Global smartphone shipments are expected to be down high single digits year on year, while global car and light truck builds, I expect to be down 3% year on year.
Relative to disposable respirators, we anticipate a year-on-year reduction in sales of $50 million to $100 million due to continued decline in global demand.
As mentioned earlier, we are anticipating a third-quarter year-on-year operating margin headwind of 50 to 100 basis points from selling prices, net of higher raw materials and logistic costs.
On the restructuring front, which I previously discussed, we expect a Q3 pre-tax charge in the range of $50 million to $75 million as a part of this program.

Summary:
We are confident in our ability to continue executing well in the face of COVID-19 uncertainties and are raising our full-year guidance for organic growth to 6% to 9%, and earnings per share to $9.70 to $10.10.
In the second quarter, we delivered total sales of $8.9 billion.
We posted organic growth of 21% versus a 13% decline in last year's second quarter, along with earnings of $2.59 per share.
Second-quarter GAAP and adjusted earnings per share were $2.59, up 44% compared to last year's adjusted results.
Year to date, we have returned $2.5 billion to shareholders in the form of dividends and share repurchases.
Organic growth is estimated to be 6% to 9%, up from the previous range of 3% to 6%.
We now anticipate earnings of $9.70 to $10.10 per share against a prior range of $9.20 to $9.70.