Measuring workplace exposure to Cr(VI) compounds in air is essential for assessing health risks and complying with legal limit values. SEEF has its own Casella low- and high-volume pumps for the accurate collection and analysis of air samples in accordance with applicable standards. Our work is not limited to the Netherlands; our expertise can be deployed throughout Europe. SEEF also carries out exposure measurements in offshore environments and ATEX zones, where additional safety requirements apply.
How is exposure to Cr(VI) measured? #
Exposure measurements are carried out by collecting air samples in the breathing zone of workers or at specific locations in the working environment. The collected particles are then analysed in the laboratory to determine the Cr(VI) concentration.
Standards for exposure measurements #
SEEF carries out air measurements in accordance with NEN-EN 689, the standard for assessing exposure to hazardous substances by inhalation. This standard describes:
- How representative air samples must be collected.
- How measurement results must be analysed and evaluated.
- When repeat measurements are required to verify exposure levels.
Filter choice: quartz vs. PVC #
The choice of filter is critical for reliable measurements:
- Quartz filters: Contain no chromium and therefore produce reliable results without interference.
- PVC filters: Widely used, but contain naturally occurring chromium and can give false-positive results, particularly when high oxygen concentrations are present in the solution.
- Some laboratories correct for this by using a reference filter and subtracting its value from the measurement results. This can, however, lead to an inaccurate estimate and underestimation of the actual risk.
Legal limit values for Cr(VI) in air #
The legal limit value for Cr(VI) in air in the Netherlands, Germany, and France is 1 µg/m³ time-weighted average. This means that the average exposure during a working day must not exceed this value.
To put this in perspective: a sugar grain weighs on average 400–600 micrograms. This means that only 1/500th of a sugar grain of Cr(VI) is sufficient to contaminate one cubic metre of air up to the legal limit. This illustrates how extremely small quantities of Cr(VI) can already pose a significant health risk.
Case study: exposure measurement during renovation of a listed steel facade #
In 2024, SEEF carried out an exposure measurement at a property in Amsterdam. During a prior inventory, Cr(VI) had been found in the paint on metal window frames and in the glazing putty. The measurement was aimed at determining the Cr(VI) exposure level during the removal of the windows and sealant beads, carried out simultaneously with an asbestos clearance measurement by a third party.
- Measurement setup: Two workers inside the containment were monitored, as well as two stationary measurement points to establish the background concentration.
- Work activities: Removal of glazing putty and glass panes using a multi-tool and suction cup, followed by the removal of paint residues.
- Measurement duration: 165 minutes, to satisfy the requirements of both the asbestos clearance measurement and the Cr(VI) measurements.
Results:
| Measurement point | Duration (min.) | Concentration (µg/m³) |
|---|---|---|
| Remediation worker | 165 | 1,42 |
| Support worker | 165 | 10,42 |
| Stationary point 1 | 165 | 1,18 |
| Stationary point 2 | 165 | 6,76 |
The results show that the support worker was exposed at a level 10.42 times above the legal limit. Although the remediation workers inside the containment were adequately protected with full-face respirators (protection factor 40), it was recommended that all workers in future activities wear at minimum a half-face mask with P3 filter. Additional repeat measurements and a decontamination procedure to minimise secondary exposure were also recommended.
Conclusion #
Cr(VI) exposure measurements are essential for protecting workers. SEEF carries out these measurements in accordance with strict standards, using the most reliable methods to accurately determine actual exposure risks. The choice of filters and analytical methods plays a key role in obtaining reliable results. We can be deployed throughout Europe, including in offshore and ATEX zones where additional safety requirements apply.
For more information about exposure measurements and risk assessment:
- Email: info@seefbv.com
- Phone: +31 (0)85 047 05 74
