Risk-based assessment vs. hazard-based assessment of adhesives or replacing the tiger with guinea pigs is not an option for adhesive bonding technology

The possible change from a risk-based assessment of chemicals to an assessment that focuses on hazards does not appear to be wrong at first glance. What is the problem?

Groß: At first glance, you are right. A closer look reveals the problem. I fear that the consequences of such a paradigm shift are not really clear to the public and thus to the level of political decision-makers.

What communication problem do you expect?

Groß: Admittedly, the regulatory approach based on hazard assessment is effective in terms of public relations, not to mention populist: It follows the skeptical view and prejudice prevailing in the public that »chemicals« are fundamentally dangerous. This leads to the widespread belief that, to put it simply, »chemicals« are fundamentally »hazardous substances«.

Hazardous materials are hazardous materials, dangerous materials are dangerous materials. I don't see this as a communication problem...

Groß: I will not contradict that and you will not hear any belittling words from me! The central aspect for me is how we deal with hazardous substances and with substances in general, including chemical substances. And this approach also defines communication for me. Let me illustrate this with an example: water is dangerous as hot steam and a toddler can drown in a 1m deep swimming pool. Nevertheless, water is not a »hazardous substance«. The decisive factors are always the circumstances and the exposure, i.e. the intentional or unintentional exposure to external influences, must also be taken into account.

No contradiction – but what do you see as the challenge for adhesive bonding technology?

Groß: I would like to quote Paracelsus, a formative medical personality between the Middle Ages and modern times and the pioneer of pharmaceutical chemistry: »All things are poison, and nothing is without poison. Only the dose makes a thing not a poison. « This 500-year-old insight is still fully valid today and will not lose any of its unconditional validity in the next 500 years either.

Ok, but that doesn't explain the dreaded challenge of a hazard-based approach...

Groß: Yes, it is! If, as is undeniably true, »all things are poison«, I cannot avoid a »poison«, i.e. a substance, even a dangerous one. That said, it is not about the substance itself, but about how it is handled. I will explain this using a generally understandable example: you go to the zoo and look at tigers. The tiger is dangerous, so it is the »poison«, i.e. the »hazardous substance«. The fact that all visitors are left undisturbed has to do with the fact that everyone involved, zoo operators and zoo visitors alike, are aware of the »poison«, i.e. the »hazardous substance«. Protective measures have been taken and implemented in terms of risk assessment: the tiger, the »poison«, the »hazardous substance« is in a cage. In other words, you and I and everyone else will not come into contact with the »poison«, the »hazardous substance« (= tiger) under foreseeable conditions and circumstances and in accordance with regulations.

If we look at the tiger in its natural habitat, the jungle, the »poison« or »hazardous substance« tiger is no different. What changes is the probability of coming into contact with a tiger. This is because the protective measures resulting from a risk assessment for risk minimization are missing in the jungle.

So far, so clear – the decisive factor is to have no contact that leads to an unacceptable risk. So what is the challenge of the hazard-based approach?

Groß: It's quite simple! I'll stick with this example: the tiger, i.e. the »poison« or »hazardous substance« is simply banned based on a hazard-based assessment. Full stop! Mind you, even in the zoo! And that's despite the fact that risk-minimizing protective measures are in place there that have been verifiably effective, foreseeable access and circumstances, and proper behavior. We would still be free to continue going to the zoo. It's just that we wouldn't be able to see any tigers anymore – because they're banned there as »hazardous substances.«

This means that the tiger cage will be available for guinea pigs, for example...

Groß: A good example – the »poison« or »dangerous substance« tiger is simply replaced by a »non-poison« or »non-dangerous substance«, for example in the form of a guinea pig.

Transferring this model to hazardous substances sounds problematic...

Groß:  ...that's right, the paradigm shift from the proven and successful risk-based assessment to the hazard-based assessment means that the »hazardous substance« is banned – with no ifs, ands, or buts, and without an assessment of the consequences from other points of view.

At least the issue of »residual risk« would be resolved once and for all, wouldn't it?

Groß: Yes and no. Take formaldehyde, for example, which occurs naturally in wood, among other things. This is a hazardous substance. However, banning it does not eliminate the residual risk, because we can measure naturally occurring concentrations of formaldehyde during a walk in the forest and are consequently exposed to this.

Furthermore, we simply have to accept that we have to live with residual risks in all areas of our lives, regardless of »hazardous substances«. You can make your house or apartment burglar-proof. However, you cannot rule out the residual risk that it will still be broken into. Even when flying on vacation, there is a residual risk despite the highest safety standards in the aviation industry. If you cross the street as a pedestrian, however carefully, there is a residual risk. Even when you visit the zoo to see the tigers, there is a residual risk: you trust that the cage is securely locked and that you will not come into contact with the »dangerous tiger«.

The example makes a lot of things clear. What does it mean for adhesive bonding technology?

Groß: It's quite simple! Let's replace the »hazardous substance tiger« with a »reactive adhesive«, e.g. based on epoxy resin. With the risk-based regulatory approach to hazardous substances prevailing today, the reactive adhesive is used successfully in compliance with the necessary safety requirements for avoiding contact and exposure, and with minimal residual risk in technological, economic and ecological terms. If the regulatory approach were hazard-based, however, the adhesive would simply be forbidden!

What about alternatives?

Groß: Of course, because – analogous to the guinea pig visit to the future zoo – we would still be free to continue using adhesive bonding technology. Only now we would only be allowed to use kindergarten adhesives for adhesively bonded joints. But for 75-meter-long rotor blades in wind turbines or for highly safety-relevant windshields in cars or in the ICE, this is not an alternative.

So we have to stick with a risk-based approach to regulation if we don't want to hinder technological development...

Groß: I consider this to be imperative. It gives politics the chance to create framework conditions that, on this basis, refocus on the utilisation of what is internationally technically possible and necessary. This is a central prerequisite for innovation in Europe. After all, adhesives are not used because it is »chic« or »hip« or »modern«. Adhesive bonding technology is used to fulfill technological, ecological and economic product requirements that are best or only met by using adhesive bonding technology.

What would happen if we evaluated adhesive bonding technology hazard-based and used it in this way in the future?

Groß: Our technical possibilities would be limited in the foreseeable future. After all, adhesives are used today for everything from cars to dental crowns, from micro to macro, under water, on water, on land and high in the sky and into space. There is hardly an area left in which adhesive bonding technology is not used or has to be used. Adhesive bonding also supports other goals that are currently in the focus of sustainable product design. One example is the adhesive bonding of car windshields. Thanks to the joining technology of adhesive bonding, the windshield becomes a structural element. The adhesively bonded joint contributes to weight reduction by increasing the rigidity of the vehicle. In other words, if the windshields were mechanically inserted with rubber seals, as they were in the past, a car would be significantly heavier.

Adhesive bonding in the car body-in-white – the next example – contributes to passenger safety. In the event of a head-on collision, the energy of the impact is absorbed by the mechanisms of action of adhesive bonding technology in the engine compartment and thus not transferred to the passenger area.

Adhesive bonding makes it possible to achieve the desired energy transition. The rotor blades of wind turbines are purely adhesively bonded constructions. Any other joining technology would minimize the energy yield to such an extent that wind energy would no longer be an option. In fact, the development of alternative energy sources is unthinkable without adhesive bonding technology according to the current state of the art.

And we would quickly reach our limits when it comes to digitization. The IT hardware only works because adhesives are used as a joining technology and, increasingly, for heat management. This also applies to smartphones and other mobile devices. It is the adhesives that make it possible to meet the increasing demands in the first place.

Thank you for these examples. So the risk of technological regression would be great and future developments in these and other areas would be much more difficult?

Groß: Yes, but there is another point that is important to me at this point: polemics and superficial considerations are completely out of place when it comes to this topic. But a »poison-free environment« for Europe is utopian. Because, as quoted at the beginning, the following still applies today: »All things are poison and no thing is without poison.« It is therefore impossible to exclude residual risks. However, it is our responsibility to minimize them, and this is therefore a central challenge. For me, this means that, in and for Europe, the utilisation of what is technically possible and necessary internationally must be given priority again when creating framework conditions, while weighing up the risks. And this is made possible, for example in adhesive bonding technology, by the proven risk-based assessment. This minimizes the unavoidable residual risks and, on the basis of the existing regulations, takes into account the health and environmental impacts in a way that is exemplary worldwide to date. And at the same time, it leaves room for necessary innovations.

A hazard-based approach, on the other hand, only leads to bans and »stifles« urgently needed technological developments. And it does not lead to »toxic freedom«. A »toxic-free Europe« is utopian. A »toxic-free Australia«, a »toxic-free Africa« etc. is also utopian. The same applies to residual risks.

One argument in favor of a risk-based approach to assessment is the possibility of reducing bureaucracy and regulation. How do you see this?

Groß: A good example of superficial observations. The fundamental goal is not in question – we have to quickly and tangibly reduce bureaucracy and regulation and thus verifiably improve and simplify matters for authorities and companies. This also applies to the chemicals strategy. Bureaucracy and regulation must be steered back onto a manageable course.

The question is how. At first glance, a risk-based assessment may seem to many to be a suitable instrument. The thinking is along the lines of: banning is easier in terms of effort than assessing risks, and above all, it is less bureaucratic! To stick with my zoo analogy: replacing all animals with cuddly toys also means that our industrial future in Europe looks different. That would be disruption in its purest form.

Therefore, there is no way around maintaining the proven risk-based approach. In this context, the focus on the utilisation of internationally technically possible and necessary measures for creating framework conditions must once again be the central focus, including in the chemicals strategy and for adhesive bonding technology. A central task of politics is to return to this, and that includes pragmatic and rapid implementation.

Thank you for the interview!