The way you suggest the crew should be very effective in a way that they would start listening to your words immediately. Sometimes, the suggestions should be done after you have taken some actions in the area you are providing suggestions. When you suggest the crew to wear the boots that are most appropriate for the work place then you should have already done a research in this area and then suggest the crew as to how some boots are meant to be for work location. You could explain the design and making of such boots to the crew so that they understand the reasons behind the suggestion that is provided by you.
It does mean that you should be first knowing what the best work boots today look like. When you visit the online stores you would get an idea about this and thus would be able to evaluate all the features that are provided with each of the brands that are manufacturing the boots and you would also be able to understand the difference between each model of the boots that are manufactured by various brands. It is good that you go by brands but make sure that you remember the fact that not all brands would be into the manufacturing of the boots that would be more applicable for the work location.
Hence, it is recommended that you go through the complete details about the work boots that are meant for the work location, know their design and then suggest the crew to wear the best of these models and designs so that they are safe while working in the dangerous or hazardous environment. When the crew is safe then the work completion percentage would be much better which is what you should be communicating in return to the higher management.