ᐅ ETICS -> Polystyrene -> Hexabromocyclododecane (HBCD) and Biocides!?

Good morning,

My wife and I have recently secured a house in a small new residential development.

In the construction and service description, it states that an "ETICS" is used as the exterior render. We assume that this refers to a typical External Thermal Insulation Composite System (ETICS) with polystyrene insulation. Online information has made us uneasy because the flame retardant hexabromocyclododecane (HBCD) is classified as an environmental pollutant. Additionally, it is mentioned that biocides are used in the insulation to prevent algae and mold growth.

I am curious whether this is generally always the case when the term "ETICS" is used? I have already raised these questions with the developer but would also like to hear from the experts here in the forum whether this is really a serious issue. What are your opinions on this? Should the health aspect also be considered?

Or is it not so critical? Considering how many houses in Germany would be affected...

Many thanks and best regards!
Gatho

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link removed by moderation; please observe the forum rules.

Thank you!
Building Expert

Hello,

thank you Bauexperte for the correction, I missed the rule about no links being allowed – sorry. :/

Please just try searching "NDR polystyrene" on Google. The first link is relevant to the topic.

Best regards
Gatho

Gatho schrieb:
I’m curious whether this is generally always the case when it comes to the overall term "ETICS" (external thermal insulation composite systems)?

Instead of combustible plastics, ETICS can also be made using mineral or natural building materials. As far as I know, there are also mineral wool insulation boards that can be covered with plaster. In cavity wall construction, mineral wool insulation can of course also be used. Then there are perlite, expanded clay, etc. Or wood fibers (well, those are combustible, right?), and so on.

Biocides should, if used at all, only be applied superficially in the plaster. In my opinion, this has nothing to do with ETICS.

Tip: Build a cavity wall with a brick veneer. Or use timber frame construction. With a developer, you might be able to build with brick cladding and then use mineral-based insulation. That will be expensive (especially with a developer).

By the way: In a legally built house today using approved building materials, hexabromocyclododecane should not be found. It has been banned since 2013.

Hi Gatho,

I agree with Bieber0815—if you want to avoid combustible materials in your external thermal insulation composite system (ETICS), you can either

· Insulate with mineral wool instead of polystyrene

· Build monolithically (e.g., with Poroton or similar materials)

· Use a double-wall construction with facing bricks and mineral wool insulation in between (this also avoids biocides in the plaster)

All of these options will involve significantly higher costs, assuming your general contractor/developer even offers them. And with the monolithic option, you’ll often have to accept poorer insulation values.

Every solution has its pros and cons, and you’ll always find someone saying, “this is toxic” or “that could cause issues.”

However, you should always consider these concerns in the context of today’s analytical methods and capabilities. Nowadays, many things are labeled “dangerous,” and we tend to feel like we’re constantly being exposed to harmful substances. But that’s mostly because we can now detect contaminants at concentrations so low that they are far below any hazard threshold.

Many of the materials used in our parents’ homes, in which we have lived for decades, are now classified as highly toxic waste. Smoking was once considered healthy, and the wood preservatives my father used to paint the garden fence probably killed every bark beetle that looked at it…

Don’t get me wrong—being smarter today and avoiding these hazards is absolutely right and commendable. But sometimes we may be going overboard. Compared to the past, we live in a much healthier and more ecological environment. Remaining risks should be eliminated when possible, but we’re at a level where fear-mongering often hinders careful and rational decision-making.

I’ll stay out of the debate on whether polystyrene should be classified as hazardous waste or if HBCD is truly toxic. The lethal dose (LD50) for rats is over 10 g per kg of body weight, which translates roughly to 700–800 g for a human. Salt’s lethal dose is probably much lower than that…

For that reason, I’ve decided to consider the issue as “not that serious,” and yes, we are building with a polystyrene ETICS.

Whether that is really the right choice, feel free to ask me again in 30–40 years.

Best regards,
Andreas

Poisons in plaster are actually unnecessary if you use a mineral high-quality scratch coat. Then you don’t need to rely on harsh chemicals anymore...

There is an intense marketing battle in the media regarding External Thermal Insulation Composite Systems (ETICS).
Rockwool, the world’s largest manufacturer of stone wool and glass wool insulation systems, is running negative campaigns against EPS (expanded polystyrene).
In response, the EPS lobby is launching campaigns against mineral fibers.

Consumers are left with little chance of making an informed decision.

What is important is that the insulation is installed professionally. The respirable fibers in mineral wool should, of course, not remain airborne inside the living spaces afterwards. For EPS insulation, it is essential to install appropriate fire barriers where required, and so on.

If these points are taken into account, in my opinion, the German regulations provide sufficient protection, allowing you to choose your insulation system based on economic efficiency and personal preference without compromising your own health or that of your family.