Translation — the French version prevails.
When thermal insulation becomes a construction liability
Hexabromocyclododecane was added for decades to expanded and extruded polystyrene insulation panels to meet fire protection requirements. At installation, it promised a safer material. At removal, it reveals above all a far more complex legacy.
The problem with HBCD is not that of a spectacular or visible pollutant. It is that of a discreet additive, dispersed in facades, roofs and sub-slabs, which today turns millions of square metres of insulation into materials requiring careful handling during any renovation or demolition.
Pensé pour ralentir le feu, le HBCD a surtout laissé un immense stock d'isolants devenus problématiques au moment de la rénovation.
Classé polluant organique persistant depuis 2013, il ne change pas seulement la lecture sanitaire du bâtiment : il change aussi la filière de dépose, de tri et d'élimination.
« HBCD illustrates a problem typical of recent construction: we wanted to make a material safer against fire, and in doing so created an environmental liability that re-emerges at the time of renovation. »Batiscan — Site synthesis
From the first brominated flame retardants to the current challenges of removal and waste disposal.
The chemical industry massively developed flame retardants to meet growing fire safety requirements for synthetic materials. Brominated compounds offered an unbeatable efficiency-to-cost ratio for polymers.
EPS (expanded polystyrene) and XPS (extruded polystyrene) panels gained ground in building envelopes. Their thermal performance attracted architects and building owners alike, but their flammability required the addition of flame retardant additives.
Hexabromocyclododecane became the reference additive for expanded and extruded polystyrene panels used in façades, roofing and under-slab applications. Its typical concentration (0.7 to 2.5% by mass) remained invisible in use but would prove decisive at the time of removal.
With the spread of external thermal insulation composite systems (ETICS), inverted roofs and prefabricated solutions, HBCD was incorporated into a large proportion of modern insulation in the Swiss building stock. Early energy renovation programmes accelerated this uptake.
HBCD was listed as a Substance of Very High Concern (SVHC) at European level. Environmental persistence, bioaccumulation and toxicity to aquatic organisms were documented.
Source : ECHA — Candidate List of Substances of Very High Concern
The first comprehensive EU risk assessment confirmed that HBCD is persistent, bioaccumulative and toxic (PBT). It was found in marine sediments, fish and predatory birds at concentrations of concern.
Source : European Commission, Risk Assessment Report — HBCDD, 2006
Scientific studies detected HBCD in human breast milk, blood and marine sediments as far as the Arctic. The substance is ubiquitous in the global environment, transported by atmospheric and oceanic currents.
Source : Covaci et al., Environment International, 2006
Classified as a persistent organic pollutant (POP), HBCD was added to Annex A of the Stockholm Convention. Its use is now subject to a global elimination framework. Signatory countries must ban its production and use, with limited temporary exemptions for recycling.
Source : Stockholm Convention, Annex A, Decision SC-6/13, 2013
Switzerland banned the use of HBCD through the Ordinance on the Reduction of Risks from Chemical Products (ORRChim). New polystyrene now uses alternatives (PolyFR, polymeric FR). The issue shifted from a market-access problem to a management challenge for materials already in place.
Source : ORRChim, Annex 1.14 (RS 814.81), Switzerland
The Federal Office for the Environment published recommendations for the management of polystyrene waste containing HBCD. The main constraint is the separation of materials and the prohibition of recycling without prior verification. Disposal is carried out through adapted incineration.
Source : FOEN, recommendations for the management of EPS/XPS waste containing HBCD
Façade and roof refurbishment projects brought HBCD back to the forefront. What went unnoticed during installation has become a matter of sorting, waste streams and construction costs. As building envelopes from the 1980s–2010s come back into renovation cycles, HBCD is increasingly a concrete diagnostic issue.
In Swiss diagnostic practice, any polystyrene installed before 2013 is presumed suspect and verification is recommended prior to removal, to ensure correct waste stream allocation. HBCD is among the substances screened in hazardous materials surveys before demolition or major renovation, alongside asbestos, PCBs, PAHs and lead.
HBCD is not a primary material — it is a hidden additive in insulation. The visible substrate is EPS/XPS; the hidden problem is the brominated flame retardant.
Panneaux sous l'étanchéité des toitures plates et en pente. C'est la source principale en volume.
Systèmes d'isolation thermique par l'extérieur — crépis sur panneaux EPS. Des milliers de m² par bâtiment.
Panneaux de façade ou toiture avec noyau polystyrène. Fréquents dans les bâtiments industriels et tertiaires.
Couches de polystyrène en isolation phonique et thermique entre les étages.
Isolation en polystyrène des caissons. Souvent oublié lors des diagnostics.
Complexes de doublage isolant (polystyrène + plaque de plâtre) sur les murs.
Any insulation polystyrene installed before 2013 is presumed to contain HBCD until proven otherwise (GC-MS analysis). Removal of these materials requires separation and prohibits recycling without prior verification. An analysis is recommended before removal.
In a building, HBCD cannot be detected by the naked eye as a spectacular pathology. It hides in perfectly ordinary insulation. That is precisely what makes it operationally significant: without a diagnosis, the removal of EPS or XPS insulation may be treated as a simple envelope package, when in reality it falls under a specific control, sorting and disposal logic.
For Batiscan, the HBCD topic is therefore less a question of chemical narrative than a question of construction-site decision-making. Should analysis be carried out? Which zone is affected? What should be done with the removed panels? Which disposal chain should be planned? When should this cost be integrated into the assignment?
In Switzerland, HBCD directly concerns the stock of buildings insulated before its ban. The topic intersects with several current dynamics: energy renovations, facade refurbishments, envelope remediation, major alterations and partial demolitions. The more the envelopes from the 1980s to 2010 reach a new intervention cycle, the more HBCD becomes a concrete diagnostic issue.
In other words: HBCD is not an archive of the chemical industry. It is a liability of the contemporary built environment.
HBCD is listed in Annex A — elimination. Signatory countries must ban its production and use.
Ban on the use of HBCD in Switzerland. New polystyrene uses alternatives (PolyFR).
HBCD is among the substances investigated in pollutant surveys before demolition or major renovation, alongside asbestos, PCBs, PAHs and lead.
Polystyrene containing HBCD must be separated and cannot be recycled without prior verification. Disposal takes place in appropriate incineration facilities.
« The real risk of HBCD in buildings is not its visibility. It is precisely that it is forgotten until the day the insulation is removed. »Batiscan — Diagnostic synthesis
Listing of HBCD in Annex A (2013) and identified alternatives.
FOEN recommendations for the separation, sorting and disposal of insulation containing HBCD.
Swiss legal basis for the prohibition of HBCD in chemical products.
Swiss reference fact sheet on HBCD in construction materials.
Comprehensive evaluation by the European Chemicals Agency.
Describe the building, the planned works and the timeline. We will get back to you with the recommended scope of intervention.
