Hazard, Risk & Safety We all hear these terms on a daily basis.
So and so a chemical, physical or a biological agent poses a risk; This or that product is
a hazard or behaving a certain way is unsafe. A lot of the time “hazard” and “risk”
are freely used to mean the same thing. However they are not.
Hazard is the potential to cause harm. Risk on the other hand is the likelihood of harm
in defined circumstances. But what does this actually mean? Let’s
look at two examples First, Potassium Dichromate: it sounds scary
and it is indeed a hazardous substance that is both toxic and carcinogenic.
It is used in some cases to analyse exhaled breath for alcohol. For this purpose it is
sealed in a tube. Therefore although it is intrinsically a hazardous substance, if used
and managed as described, it presents little or no risk to people or the environment.
Now let’s look at the opposite case. Flour would not be considered by many to be a hazardous
substance. However, if a baker were to be exposed over a period of time to airborne
flour, he/she could develop dermatitis, conjunctivitis, rhinitis and even asthma.
So even something that is considered a low hazard can present substantial risk and vice
versa. Risk is always a probability, influenced by
the level of exposure. To evaluate the risk we have to take many factors into consideration.
How, where, how much and how long one can be exposed to the hazard are all things to
be taken into account. Toxicological research can map the potentially
harmful properties of a product, be it chemical, physical or biological and it can also set
a limit under which exposure will have no effect.
Based on this research, a risk can be calculated based on frequency, conditions and length
of exposure. However, some types of risks are hard to quantify,
either because of the complexity of a system, like in the case of climate change, or because
we still lack some of the tools to measure it, like in the case of nano-materials.
When there is no consensus on the level of risk, policy makers sometimes who have the
responsibility to decide on safety levels apply a precautionary principle.
“When sufficiently established elements suggest that an activity is seriously expected
to potentially produce irreversible damage to health or the environment, measures should
be taken even if the definite proof or the causal link is not yet formally established
with absolute certainty.” (Communication of the EU in 2000)
It is best to err on the side of caution. Nevertheless, the precautionary decisions
should remain proportional to this potential but uncertain risk, and be reevaluated when
new data become available. Indeed The Proportionality Principle is and
should be at the base of most legal thinking. Now, how can we manage a risk?
Risk can thus be managed by limiting exposure to a danger and by the adoption of risk-reduction
measures. Prevention might be a better idea to reduce
risk. For example driving has been made safer by speed limits, the use of seatbelts, bumpers,
airbags, driver assistance systems etc. But what is considered safe? Acceptable safety
levels greatly depend on where you are on the planet, culture, socio-economic criteria
and the sector. Similarly, the safety limit adopted for a pesticide like DDT has to be
balanced with its importance in safeguarding health or food resources in some regions of
the world. For each specific case, an acceptable safety level has to be determined. This is
thus not only a technical, but also a “political” decision.
Even if the previous steps are logical, what is considered safe has to take into account
the perception and acceptance of risk. These tend to be emotional and rational at the same
time. For example flying is commonly considered a greater risk than driving although all statistics
point to the contrary. Moreover, once a perception of risk sets in,
it is very hard to change. Even if all evidence points to the opposite.
For example: fear can be fuelled by debatable science and poor or even sensationalist interpretation
of a study by the media. A very limited study that indicates that Substance A could be harmful
to mice and would merit further research quickly turns into a ‘Substance A kills’ headline.
Once fear sets in, even if risk is not proven, the precautionary principle is often pulled
out of the hat. In a nutshell, risk and
perception of risk are not always aligned; this can make political decisions difficult to make, in these cases it is especially important to base them
on facts rather than on opinions. These facts can be gathered from scientific
reports published by reference institutions, but these reports are often written in a technical
language that is not accessible to anyone but the specialists. GreenFacts offers faithful
summaries of those reports so that non-specialists can get the information they need to build
their own opinion.