Modeling Limitations

Modeling Limitations
By: Ron Benjamin

It is fairly simple to define the term “environmentally non-toxic”. That would be something that does not harm the environment.

What’s not so simple, though, is to measure whether something is environmentally non-toxic or not. For toxicity depends on dosage. A small amount of aspirin is good for us. Large amounts can kill. In the right dose, aspirin is safe and effective. In the wrong dose, it is toxic.

In order to project whether or not man-made chemicals are toxic to the environment, scientists use computer modeling to estimate the effect a given chemical may have on the environment (rather than releasing it to the environment). These computer models are helpful in guiding the determination of safe exposure limits and in helping us to handle chemicals in ways that are positive rather than negative.

However, it is important for us to realize that computer models are designed and built by modelers for specific applications. Too often, a computer model designed for one chemical or purpose is used to determine how another chemical or purpose might behave.

Such is the case with silicones. Silicone chemistry is not purely organic chemistry. Rather, silicones are classified as inorganic organics because they are molecules formed with both carbon (C) and silicon (Si). Carbon is plant-based and thus organic. Silicon is mineral-based and thus inorganic.

Unfortunately, though, models designed to analyze organic chemicals have been used to analyze silicones. And the modeling that has resulted isn’t totally accurate.

The Minister of the Environment in Canada recognized this situation and in 2011 determined to find an answer to the question of whether or not the computer modeling for liquid silicone was to be believed. Rather than ban the use of liquid silicones based upon the modeling data, he commissioned an independent study to be conducted by three scientists which measured the actual effect of silicones in the environment. Rather than computer modeling data, he asked for real environmental data to be measured.

The results of the 83 page scientific study were published in February of 2012. The study found that despite thousands of pounds of liquid silicone contained in shampoos, deodorants, lotions, etc. going down drains every year, there was no harm being done to the environment based upon actual measurements in the environment. In fact, the study determined that even if twice the amount of liquid silicone were being dumped down the drains, there would be no environmental harm done.