Organic revenues in the second quarter were up 19% year-over-year, adjusted EBITDA was up 21% and adjusted earnings per share of $0.94 increased 38% versus last year.
Revenues also grew in each geography, including organic growth of 19% in the Americas, 27% in the EMEA and 9% in the Asia-Pacific region.
Total organic revenues increased by 9.5% versus the second quarter of 2019, which had no COVID-19-related impacts with double-digit growth in HHC and Engineering Adhesives and mid single-digit growth in Construction Adhesives.
Strong volume leverage in the quarter, coupled with pricing benefits and operational efficiencies we're driving in the business offset significantly higher raw material costs and drove a 21% increase in EBITDA dollars year-over-year.
Raw material input cost increased in the second quarter by about 10% from the end of 2020 with some raw materials increasing more rapidly than we forecasted.
We have implemented $150 million of annualized price adjustments to date and we'll implement an additional $75 million in the third quarter.
We now expect the year-on-year raw material inflation to be over 10% and expect that our pricing will fully offset raw material increases by the end of the third quarter.
And the actions we have taken on price and to drive efficiencies across our business enabled us to seamlessly serve our customers and achieve our profit targets in the quarter, while at the same time increasing our debt paydown over last year's level, in line with our target for $200 million of debt reduction in 2021.
Hygiene, Health and Consumable Adhesives' second quarter organic sales increased 3.3% year-over-year, which is an outstanding result considering the comparison to a very strong quarter last year when the business grew 7% organically.
HHCs segment EBITDA increased by 11%, significantly more than the top-line growth and EBITDA margin was strong at 14.7%, up 70 basis points versus last year.
Construction Adhesives' organic revenue was up 23% versus last year with strong growth in both flooring and commercial roofing as share gains and improving demand drove significantly improved top-line performance versus 2020.
Even compared to a strong non-COVID impacted second quarter of 2019, organic revenue was up 4%.
Construction Adhesives EBITDA increased 4% versus last year as strong volumes were offset by higher raw material costs, unfavorable mix and some temporary manufacturing costs that were required to return to normal service levels after the extreme weather event in the first quarter.
Engineering Adhesives' results were extremely strong with organic revenue up nearly 40% versus last year, reflecting share gains and improving end market demand.
Sales increased versus last year in all 14 of our Engineering Adhesives end markets with exceptional growth in adhesives for automotive, recreational vehicles, woodworking, electronics and insulating glass.
And looking back to the non-COVID impacted second quarter of 2019, organic revenues were up 11%.
Engineering Adhesives' second quarter EBITDA grew 42% year-on-year, driven by exceptional volume performance.
Net revenue was up 22.7% versus the same period last year.
Currency had a positive impact of 3.9%.
Adjusting for currency, organic revenue was up 18.8%, with volume up 17.4% and pricing up 1.4%, with most of that pricing realized in the second half of the quarter.
When compared to Q2 2019, organic revenue increased 9.5% for the total company with strong organic growth for all three GBUs.
Adjusted gross profit was up 17.4% year-on-year, and gross profit margin was down 120 basis points as volume growth and pricing gains were offset by higher raw material costs.
Adjusted selling, general and administrative expense was down 130 basis points as a percentage of revenue, reflecting volume leverage, savings associated with our business reorganization, and general cost controls, offset by higher variable compensation than last year.
In total, adjusted operating income margin improved by 20 basis points year-over-year.
Net interest expense declined by $1.3 million, reflecting lower debt balances.
The adjusted effective income tax rate in the quarter was 26.8% compared to 27.6% in the same period last year.
Adjusted EBITDA for the quarter of $122 million was up 21% versus the same period last year, driven by strong volume growth, pricing gains and restructuring savings, partially offset by higher raw material costs and higher variable compensation.
Adjusted earnings per share were $0.94, up 38% versus the second quarter of last year, reflecting strong income growth and lower interest expense associated with our debt reduction.
Cash flow from operations in the first half of the year of $80 million compares to $108 million in the same period last year, reflecting working capital requirements to support strong top-line performance, as well as higher raw material costs.
We continue to reduce debt, paying down $62 million in the first half of 2021 compared to $51 million during the same period last year and keeping us on track for our full-year debt paydown plan of $200 million.
Regarding our outlook, based on what we know today, we now expect full-year revenue growth to be in the low double-digits.
As you will recall, we increased our adjusted EBITDA guidance range last quarter to $455 million to $475 million and this guidance remains unchanged, given our expectations for the continued strong volume growth and accelerating pricing offsetting raw material cost increases that we now expect to exceed 10% for the fiscal year.
Based on the seasonality of our business and the timing of raw material and price increases, we expect revenues in the third quarter to be up about 15% versus the third quarter of 2020 as we continue to deliver strong top-line growth.
EBITDA margin in the third quarter is expected to be about 100 basis points lower than the second quarter on a sequential basis.
We expect cash flow to be strong for the rest of the year, allowing us to maintain our target to pay down approximately $200 million of debt during 2021.
Our 19% second quarter organic revenue growth is even more significant than it appears, considering our HHC business had a very strong quarter of 7% organic growth in the second quarter last year.
And our business, overall, grew 9.5% compared to pre-COVID levels in the second quarter of 2019.
We implemented $150 million in price increases, effective from March 1 through July 15, and we're planning an additional $75 million in price increases later in Q3.

Summary:
Organic revenues in the second quarter were up 19% year-over-year, adjusted EBITDA was up 21% and adjusted earnings per share of $0.94 increased 38% versus last year.
Raw material input cost increased in the second quarter by about 10% from the end of 2020 with some raw materials increasing more rapidly than we forecasted.
We now expect the year-on-year raw material inflation to be over 10% and expect that our pricing will fully offset raw material increases by the end of the third quarter.
Adjusted earnings per share were $0.94, up 38% versus the second quarter of last year, reflecting strong income growth and lower interest expense associated with our debt reduction.
Regarding our outlook, based on what we know today, we now expect full-year revenue growth to be in the low double-digits.
As you will recall, we increased our adjusted EBITDA guidance range last quarter to $455 million to $475 million and this guidance remains unchanged, given our expectations for the continued strong volume growth and accelerating pricing offsetting raw material cost increases that we now expect to exceed 10% for the fiscal year.