You lift a parquet plank and underneath there is a black, viscous mass. It might smell like tar or mothballs. This is in all probability PAH-containing coal tar adhesive — and you should stop removing the floor immediately.
What the Black Stuff Is
Between the 1950s and 1980s, strip parquet was routinely bonded with coal tar adhesive. This adhesive contains polycyclic aromatic hydrocarbons (PAH) — a group of over 100 compounds formed during the combustion of coal.
The PAH concentrations in these adhesives are not subtle. We regularly measure values of 5,000 to 50,000 mg/kg total PAH content. This is hazardous waste — far above every limit value.
The most critical individual compound: benzo[a]pyrene. Classified by IARC (the International Agency for Research on Cancer) as Group 1 — definitively carcinogenic in humans.
Not Every Black Adhesive Contains PAH
Important caveat: there are also black bitumen adhesives that are considerably less problematic. Bitumen looks similar at first glance — black, viscous, sticky. But bitumen contains significantly less PAH than coal tar.
You cannot reliably distinguish the two visually. The smell can be an indicator (tar adhesive smells more intense, sometimes of naphthalene), but it is not proof.
Why You Should Stop Ripping It Out
When PAH adhesive is torn out, sanded, or milled, fine dust is produced that spreads throughout the entire apartment. PAH bind to dust particles, deposit on surfaces, and are difficult to remove afterwards. You contaminate rooms that were not otherwise affected.
Additionally: PAH are absorbed through the skin. Direct skin contact with the adhesive should be avoided.
How to Get Clarity
We take a small material sample of the adhesive — a piece of approximately 2x2 cm is sufficient. The sample goes to an accredited laboratory and is analysed by GC-MS (gas chromatography-mass spectrometry) for the 16 EPA PAH compounds.
Cost: quote after initial consultation (PAH analysis is situational — scope depends on sample type and required detection limits). Result in 5–7 business days.
Afterwards you know: PAH yes or no, and at what concentration. From this it follows whether the adhesive must be disposed of as hazardous waste and what protective measures are required during remediation.
What to Do Until You Have the Result
Cover the floor again. Do not continue ripping out, sanding, or milling. Open windows if you have already exposed the adhesive. Wash your hands if you have touched it.
No reason for panic — but good reason for caution. Professional PAH remediation is plannable and calculable. Uncontrolled ripping out is not.
15-minute initial consultation, free of charge. Send us a photo — that is often enough for an initial assessment.