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Frequently asked questions about chromium-6

Chromium-6 has been detected in some of our trains. As a result, we have received a great deal of questions from current and former employees, as well as other concerned parties. Here you can read answers to the most frequently asked questions about chromium-6.

All questions and answers about chromium-6 at NS

  • Where could chromium-6 occur in trains?

    Chromium-6 may occur in layers of old paint on the exterior of train types SGM, ICM, ICR, Mat’64, loc DDAR, DDM1, E1700, VIRM and perhaps certain fastening materials.

  • Should passengers be concerned about exposure?

    No, passengers cannot be exposed to chromium-6. Chromium-6 is not hazardous in its solid form in layers of old paint.

  • Should employees be concerned?

    At the moment, we have no cause to be concerned, as long as employees utilise the prescribed safety measures. Employees are required to use proper personal protective equipment when working under dusty conditions, for example when sanding. We will continue to remind employees to follow safety guidelines in their work. Safety guidelines are also constantly monitored and amended as necessary. 

    The investigations conducted by the RIVM are geared towards obtaining more insight into the degree to which employees have been exposed to chromium-6 in the past. Employees who are concerned about their health due to past or present working conditions can contact the CAOP for more information or to register for a medical exam.

  • Can NS train crew members be exposed to chromium-6?

    No, train crew members cannot be exposed to chromium-6. Chromium-6 is not hazardous in its solid form in layers of old paint.

  • When did NS learn of this situation?

    Following reports of chromium-6 contamination at the Ministry of Defense in 2015, NS began an investigation of whether we also use paint containing the substance in our workshops. That is not the case. However, research in preparation for work on the DDM-1 train type in June 2015 determined that old layers of paint may contain chromium-6. Further investigations indicated that chromium-6 may also occur in layers of paint on other traint types (SGM, ICM, ICR, Mat’64, loc DDAR, E1700, VIRM) and certain fastening materials.

  • Where have employees worked on old layers of paint (for example when sanding?)

    The main location is the NS workshop at NedTrain in Haarlem, but employees have also sanded paint layers the workshops in Onnen, Maastricht, Leidschendam, Zaanstraat (Amsterdam), Watergraafsmeer (Amsterdam) and the former workshop in Tilburg.

  • Which work activities could have involved exposure to chromium-6?

    Chromium-6 can be released in the form of dust or smoke during sanding, grinding or welding. The risks inherent in these activities are not limited to exposure to chromium-6, but also include harmful welding fumes and fine particulates produced by sanding. These are known risks in the industry, and the current work methods and safety guidelines address these risks. We now know that old layers of paint on the exterior of some trains and certain fastening materials also contain chromium-6, so we have reviewed and updated our work methods as necessary. Research has shown that chromium-6 may be released through the following activities :

    • Cleaning trains with compressed air after sanding (this work method is no longer used)
    • Sanding for spot repairs on exteriors
    • Cutting into the wall and hull plate behind the foot-board in the grit cabin
    • Grinding/welding of the stainless steel bulkhead
    • Moving trains by means of air cushion transport (this is now performed using a new transportation method that does not use air).
  • How can you run the risk of exposure?

    In dust or vapour form, chromium-6 poses increased health risks when a person is exposed to excessive amounts (above the legal norm) for a long period of time. By taking protective measures, such as limitation of the duration of activities or the use of personal protective equipment, exposure can be minimised and risks avoided. External and independent investigations have shown that our methods of working do not result in levels of exposure that exceed the permitted norm. However, NS aims to limit exposure as much as possible. That is why we will be taking additional measures to optimise working conditions, for example, by using new dust covers and other methods.

  • What safety precautions are in place at NedTrain/NS?

    NS has a culture of safety in which employees are constantly and openly informed about potential risks in order to continuously reduce the number of safety incidents and prevent them from occurring. Employees are asked to report incidents, and they are actively notified of issues that could be done better or lessons learned from incidents. By constantly learning from incidents, NS repair, maintenance and service locations have very few safety incidents on average, and the trend has been decreasing for years.

  • How many employees have been in direct or indirect contact with chromium-6?

    It is difficult to say at the moment. The RIVM is currently conducting an investigation to identify which positions may have been exposed, and at which locations. This information could make it possible to determine how many people may have been exposed in the past. 

  • Have NS employees experienced health problems?

    Some NS employees have reported having health problems. It is not yet known whether these problems are related to exposure to chromium-6. Employees concerned about their health due to past or present working conditions can contact the CAOP for more information or to register for a medical exam.

  • Are there concerns among NS employees?

    Some employees have concerns about their health due to their past and/or current working conditions. We offer current and former employees medical exams, and we closely monitor all of the relevant measures and developments.

  • How are former employees notified?

    Former employees will be notified by means of a letter to their home address and can also search for information on the NS website ( You may also contact the CAOP if you have any questions. The CAOP acts as an independent source of information under the supervision of the social partners, and is an important knowledge centre in the field of labour issues. The CAOP also processes registrations for independent medical exams.

  • Where can I as an employee ask questions about specific work activities and their risks?

    Your supervisor can help you. The CAOP also acts as an impartial source of information for questions about chromium-6 and/or medical exams. The CAOP can be contacted via e-mail at: The telephone help desk is open from Monday to Friday between 09:00 and 17:00: 070 376 54 58. For more information, see

  • How does NS arrange for an independent review of its approach to chromium-6?

    NS believes it is important that current and former employees can have confidence in the measures taken and that they are fully informed about any past and current health risks. We do not wish to overlook any detail, so a committee of independent experts has been asked to review the approach to chromium-6 within NS. Since employees have concerns, NS wishes to be fully transparent about this matter. This independent committee, which includes a medical toxicologist and representatives of the Works Council and FNV/Bureau Beroepsziekten, was established in December 2015 and reports on its findings and recommendations in the form of progress reports that are published here’.