Sampling of chromium is carried out in the inhalable fraction (E-dust).
In the GSA, the following sampling systems are available for the sampling of E-dust:
- SG10-2 with GSP10 (personal sampling)
- PM4-2 with total dust head (stationary sampling)
Personal sampling is usually performed with SG10-2 and GSP10. The air loaded with dust is sucked in with a battery-operated pump (SG10-2) with a volume flow of 10 l/min (600 l/h). We recommend a measurement duration of 4 h to achieve a volume of 2.4 m³ in order to detect 1/10 of the assessment standard (1 µg/m³). The air loaded with E-dust flows through a membrane filter, an unweighted quartz fibre filter with 37 mm diameter, on which the dust is separated.
Site-specific sampling was carried out by means of a volume flow-controlled sampling device with IFA E-dust sampling system (PM4-2) with a volume flow of 4 m³/h. The air is then sampled by means of a filter. We recommend a measurement period of 2 h. An unweighted quartz fibre filter, with a diameter of 70 mm, is used as the filter medium.
After sampling, the filter must be transferred as quickly as possible to a solution consisting of sodium hydroxide and sodium carbonate.
Analytical method for the determination of chromium(VI) compounds
Photometric determination of chromium(VI) content according to EN ISO 18412:2006 “Determination of chromium(VI) – Photometric method for low contaminated water”. The detection limit is 0.2 µg/filter.
The assessment criterion for chromium(VI) compounds according to TRGS 910 is 1.0 µg/m³ in the inhalable dust fraction (E-dust).