When transporting cylinders containing used refrigerated DOT requires that you what?

When transporting cylinders containing used refrigerants, the Department of Transportation (DOT) requires that they be properly labeled and marked with the appropriate hazard class. The cylinders must be secured to prevent movement during transport and should be transported in an upright position. Additionally, it's essential to ensure that the cylinders are in good condition and that any necessary documentation, such as a manifest or shipping papers, is provided. Compliance with all relevant safety regulations and guidelines is crucial to ensure safe transport.