And, the selenium in toner is quite different in chemical form than that used in dietary supplements. IDK offhand the difference as I have not looked into it for years.
BTW, one of the major portions of my research in graduate school involved the use of selenium oxidations. So, I have used it by the pound as selenium oxide. It smells like garlic to me.
At Kodak, selenium is used in large quantity in chemical syntheses, but they take great precautions to prevent chemical spills and vapor leaks.
Selenium is a major dopant in computer chips. If you have a short in any electronic equipment and smell that characteristic garlic or 'electronic' odor, that probably contains some seleniium compound or other. And, I am not referring to the smell of burning insulation. That is different.