https://www.ns.nl/en/about-ns/train-and-tracks/chrome-6/frequently-asked-questions-about-chromium-trioxide
Frequently asked questions about chromium trioxide | Over NS | NS
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...
frequently asked questionsabout chromiumtrioxide