Why Accurate PAH Analysis Is Essential for Safe Asphalt Management

The use of tar asphalt in Dutch road construction was permitted until January 2001. Its use, however, was strongly discouraged after 1995. Tar asphalt can contain high concentrations of carcinogenic PAH compounds (Polycyclic Aromatic Hydrocarbons). This carcinogenic property can have major health consequences.

Since 2001, tar-containing asphalt has been prohibited and policy has been aimed at preventing the spread of harmful PAHs in the environment. This makes environmental-hygienic research into asphalt a key aspect of road engineering. Reliable and accurate determination of the presence of PAHs is crucial. Laboratory test results are used to determine whether old asphalt may be (partially) reused.

Eurofins’ analytical options for PAH determination in asphalt

First, a so‑called PAH detector test can be performed in the laboratory. This test allows for a qualitative assessment of each layer to determine whether it is suspected of containing PAHs or not. A positive result indicates a level of tar content so high (>250 mg/kg) that the layer may not be reused.

Below this threshold, further investigation is required. The layers that show a negative result are usually subjected to quantitative PAH analysis using GC‑MS.

We hold the recognitions and accreditations required to perform these analyses, as described in CROW Publication 210, Guideline for Handling Reclaimed Asphalt:

• The executing laboratory, Eurofins Omegam, holds the NEN EN ISO/IEC 17025 accreditation from the RvA.
• Determination of layer thickness and structural composition in drill cores: according to RAW test 77.1 and NEN EN 12697 36.
• Detection of Polycyclic Aromatic Hydrocarbons (PAHs); PAH detector (PAH marker): according to RAW test 77.2.
• Determination of the concentration of Polycyclic Aromatic Hydrocarbons (PAHs); GC MS with petroleum ether (PE) extraction.

Because Eurofins is accredited for the GC MS analysis, the time consuming and costly DLC method can be omitted.