One of the most commonly asked questions with regard to any chemical that is used in the marketplace is “is it biodegradable”?
This applies to insecticides, detergents, dry-cleaning fluids, herbicides and so on. And the reason is that today we have an understanding of ecosystems that we didn’t have 50 years ago, and the need for any chemical that we place into the environment to biodegrade, and therefore have no lasting impact on the environment.
50 years ago, the very opposite was the case. You see. another word for “biodegradable” is “unstable”. And back then, that was a bad thing. Back then we wanted chemicals to last for, well, forever if possible. When we sprayed a surface insecticide we wanted it to last forever. And this was the great advantage of DDT. As a chlorinated insecticide it was extremely stable (ie not biodegradable), and so it could be blasted here there and everywhere, knowing that we wouldn’t have to come back for a while.
But as time marched on, we started to realize that these chemicals were starting to accumulate in the environment, and in some cases they have caused disruption of ecosystems that was never originally intended.
So now you pretty much cannot use a chemical in the marketplace if it is not biodegradable. And this even applies to dry cleaning fluids. It used to be the case that when you had your clothes dry cleaned, the chemical of choice was 1,1,1-trichloroethane, a triply chlorinated solvent that was also contained in the original formula of Preen aerosol. That now is out the door, to be replaced by something that is biodegradable. I’m not sure how well these newer chemicals work, however, as I tend not to get things dry cleaned. One thing I do know, however, is that today’s Preen is not a patch on the old stuff. Tomorrow we’ll start lookin at exactly how biodegradation works in world around us.