Can we foresee and manage unknown risk?
Chemicals is an area of great complexity. Properties and short-term effects of a single substance take years – or decades – to assess and the costs are huge. Assessing long-term effects and possible interaction between substances is impossible.
There are hundreds of thousands of chemicals floating around in society and nature around the globe. In the EU over 100 000 chemical substances are registered by companies.
Contrary to common belief, authorities assume that any substance is harmless until otherwise is scientifically proven. Nevertheless most chemicals have not been examined for their hazard to humans or the environment.
The standard procedure is to test a substance on fish or mice in a laboratory to get some idea of the hazard of the substance. The knowledge derived through this is highly insufficient, but that does not disqualify a substance from being permitted on the market.
Instead, authorities try to estimate and control the risk associated with the substance. In a risk assessment they try to assess the probability that the substance will cause harm, relying on limited, insufficient or even non-existent data regarding the hazard, where the substance is used, in what quantities it may be released, where it ends up, whether it breaks down slowly or rapidly etc.
In many ways, it´s like looking through a keyhole into a five-story warehouse, trying to figure out what the rest of the interior looks like. On this basis, chemicals may be registered for production and use all over the world.
However, time and time again it has been proven that assessing risk is impossible. The unknown factors are too many and impossible to foresee.
There are many cases when substances that have been risk assessed were later connected to disasters. The notorious substances DDT and PCB are only showcases where risk assessment has proven completely inadequate.
Scientists, politicians and NGOs today acknowledge that relying on risk assessment is unsustainable. Instead, policies should focus on the hazard of a substance.
If a substance is hazardous, it should be banned. If such a substance is deemed necessary in society, and if there is no less hazardous alternative, it should be produced and used with extreme caution, but only until there is a less hazardous alternative available.
Recommended Reports
Principles for a toxic free environment (pdf)
The Precautionary Principle:
A common sense way to protect our health and environment
