Sampling

The following sampling system is available at the GSA for the sampling of naphthalene and naphthalene-like compounds:

  • SG5100ex with thermodesorption tube type TDS-Tenax (personal and stationary sampling).      

In the case of personal and stationary sampling, the naphthalene and naphthalene-like compounds in the air are aspirated with a battery-operated and volume flow-controlled pump (SG5100ex) with a volume flow of 1.0 l/ min. We recommend a measurement period of 2 h.

A thermodesorption tube type TDS-Tenax is used as adsorption medium. The two sealing caps are removed immediately before sampling and exchanged for the two open caps. The thermodesorption tube is sampled and closed again with the corresponding caps after sampling. 

  • Naphthalene, 1-methylnaphthalene, 2-methylnaphthalene are measured with thermodesorption tubes type TDS-Tenax.
  • Acenaphthene, acenaphthylene, fluorene, anthracene and phenanthrene are measured by PAH (EPA) method.

Analysis

Subsequently, the analytical determination is carried out by means of a thermodesorber and GC-MS/FID (gas chromatography-mass spectrometry – flame ionisation detector).

Limit values

Naphthalene

According to hazardous substances legislation, naphthalene is classified as a suspected carcinogen.

The members of the ad hoc working group on Indoor Guide Values of the Federal Environment Agency’s Indoor Air Hygiene Commission have proposed a guide value II (hazard value) of 30 µg/m3 and a guide value I (precautionary value) of 10 µg/m3 for naphthalene in indoor air. 

 

If the guide value II is reached or exceeded, immediate action is required.

If the guide value I is complied with, no adverse health effects are to be expected even in the case of lifelong exposure.

Guideline value I can serve as a target value for remediation.

Naphthalene-like compounds

Naphthalene does not occur alone in indoor air, but is accompanied by naphthalene-like compounds. These compounds include methyl and dimethyl naphthalenes, as well as the tricyclic aromatic hydrocarbons (acenaphthene, acenaphthylene, fluorene, anthracene and phenanthrene). 

Naphthalene can be regarded as an indicator substance for this group of substances.

In the event that naphthalene-like compounds are detected, the ad hoc working group established provisional sum guideline values for the total group of bicyclic and tricyclic aromatic hydrocarbons:

  1. For the sum of bicyclic aromatic hydrocarbons (naphthalene, methylnaphthalene, 2-methylnaphthalene)
    • Provisional guide value I (precautionary value) of 10 µg/m3
    • Provisional guide value II (hazard value) of 30 µg/ m3
  2. For the sum of bi- and tricyclic aromatic hydrocarbons (acenaphthene, acenaphthylene, fluorene, anthracene and phenanthrene)
    • Provisional guide value I (precautionary value) of 10 µg/m3
    • Provisional guide value II (danger value) of 30 µg/ m3

To assess the concentrations of bi- and tricyclic aromatic hydrocarbons, a measurement must be made according to the PAH (EPA) method.

Measurement example: Stationary sampling