By David Constable, Science Director, ACS Green Chemistry Institute
I’ve always had a tendency to ask questions, it’s sort of how I’m made. For those of you who have had children, you might surmise that I never got out of the one-question-leads-to-another stage of childhood. I want to know how things work, how do I know something is true or false, or why can’t I do x….a seemingly never-ending parade of questions. It’s what got me into metrics ̶ because someone said something was green chemistry, and I couldn’t honestly say I knew why. This is what led me to ask, “If we’ve had 20 or more years of green chemistry, shouldn’t I expect to see a lot of evidence of green and sustainable chemistry innovations in patents?”
I decided to discover if there is evidence of green and sustainable chemistry in the U.S. patent literature, reasoning that if green and sustainable chemistry spurs innovation, we should see the number of associated patents expanding over the past 20 years or so. After all, the number of journals and scientific papers related to green and sustainable chemistry has grown dramatically over this same time, and surely one might reasonably expect a commensurate increase in patents if R&D innovations are making their way into commercial use.
Now, I would be the first to admit that inferring trends from patents isn’t easy, and it took about four years to establish a robust search strategy that seemed to retrieve patents with some connection to green and sustainable chemistry. What I discovered was a bit surprising to me, or more precisely, it threw me into depression. Out of 882,823 chemistry-related patents over a 30-year period, only 12,473 unique patents were related to green and sustainable chemistry. In 1990, about 0.5% of patents granted that year were related to green chemistry and this only grew to about 1.5% per year by the end of 2019, an average of 1.2% of all patents in the 30 year patent set.
You could argue that I didn’t really capture the true extent of green and sustainable chemistry that is happening since many innovations are being implemented, they’re just not being patented. You might also say that patents just aren’t highlighting green and sustainable chemistry, since they are focusing on the differentiation that comes in the chemistry innovation and the associated technical benefits. And, you might also say that green and sustainable chemistry innovations aren’t restricted to the U.S., and many other countries are doing a better job at these innovations than the U.S. is doing.
What I would say, in general, is that when reviewing patents that were retrieved, I was very generous in counting them as green chemistry. If I was a bit more rigorous in how I assessed “greenness,” I firmly believe I would have had far fewer patents. In fact, there is far more evidence of patents claiming, for example, to be “environmentally favorable”, whose connection to green chemistry and environmental favorability is very tenuous at best.
So where does this leave us? I think it’s fair to say that we have a lot of work to do to move from research to the translation of that research into commercial reality. We need to educate scientists and engineers to think and act differently, so they develop and commercialize innovations whose green and sustainable chemistry bona fides are not ambiguous but clearly verifiable. At the very least, it’s job security for those individuals who can deliver green and sustainable chemistry innovations, the world depends on it.