February 20, 2014

Werner Braun: Toxicity vs. hazardous substances


— As a chemist and toxicologist back in the day, I have a pretty good understanding of the difference between a substance which contains toxins but does not pose a health risk and a toxin-containing substance that should be considered hazardous.

I’ve noticed over the years that the definitions of toxicity and hazard are frequently confused, both in popular understanding and — more critically — among government regulators. This last fact can have dramatic impacts on policy decisions.

Here’s the critical point: Not everything that’s toxic should be considered hazardous. Unfortunately, some folks seem, either willingly or unwittingly, to create anxiety among the public by equating toxicity and risk. Clearly they are not the same.

Products that contain toxins are all around us, and used properly, present no hazard. Take for example a household cleaning agent containing chlorine bleach. When used as recommended, chlorine bleach is an effective cleaning agent that brightens clothes and diminishes stains. In our laundry rooms, this chemical doesn’t normally present a risk to those who use it.

However, if you were to ingest even a little bit of chlorine bleach you would likely die.

Let’s look at a more innocuous example, H2O, or water. Water is an element necessary for life, something which we use on a daily basis for drinking, cooking and bathing. Nothing could be better for us, right? Nothing could be less toxic? That’s certainly correct in most cases. However, if you got enough water in your lungs — as in a drowning accident — you would most likely die.

So, even the most helpful substances can become hazardous under the “right,” or wrong, conditions.

This comes to my mind because of recent concerns raised by the environmental community concerning coal fly ash.

For those who aren’t familiar with coal fly ash, it’s basically a component of the generation of electricity made from coal. It’s the small, light material that goes up with the flue gas when you burn coal to make electricity. Looking at it under a microscope, coal fly ash is essentially small glass beads. As such, these glass beads are inert.

Currently, coal fly ash is being “captured” at coal-fired power plants and is reused in the production of materials designed for the building industry, such as cement, bricks, gypsum board and carpet backing. This process provides a way to recycle and reuse waste that would otherwise be sent to landfills or impoundments.

Some members of the environmental community believe that because coal ash can present environmental problems under the wrong circumstances that it shouldn’t be used in certain building products or any of a number of other uses for which it is currently approved by the U.S. Environmental Protection Agency. They believe it should be labeled hazardous.

Why is there a concern?

Around five or six years ago, some impounded coal ash was accidentally released into a stream when an earthen dam failed, causing environmental damage for many downstream residents.

That was definitely a problem, as I know we’d all agree. But that event generated a movement to regulate coal fly ash and to label it as a hazardous substance.

It’s very clear that the answer isn’t to ban the use of coal fly ash altogether, or to reclassify it as a hazardous substance, but rather to regulate coal ash impoundment appropriately so this type of accident won’t happen again.

But to label coal fly ash as a hazardous material is simply overkill. Period.

We certainly want to understand what toxins are around us, but environmental regulations must be based on regulating hazard. Remember this important point: Toxicity does not in and of itself equate to hazard. We can’t allow ourselves to become solely focused on whether or not something is “toxic.” The real issue is “Is it hazardous?”

Focusing on toxicity casts an enormously broad net over an issue for which an enormously broad net is not needed.

Clearly, we need to regulate hazardous materials and to make sure that they don’t become threats to the general public. But we need to use some common sense along the way.



Werner Braun is president of the Dalton-based Carpet and Rug Institute.