Can I sell things to my workplace?
I have a job as a public school teacher. Several years ago, I created an LLC on the side producing a product nobody else was. I obtained permission from upper management to (both of these managers no longer work there), and they laid out simple guidelines, like no using school equipment, devices, building, or time to run the business, which I followed strictly. I also filled out "conflict of interest" forms every year, declaring the name of my side business, etc., declaring I won't take part of procurement decisions. Now, I discovered that one department is, to no surprise, in need of my product. Its potentially a quite big sale, so not something I want to ignore...and for a product they've given up on finding, but... Is it likely fire-able/illegal to send advertisements the place I work?

I have a job as a public school teacher. Several years ago, I created an LLC on the side producing a product nobody else was. I obtained permission from upper management to (both of these managers no longer work there), and they laid out simple guidelines, like no using school equipment, devices, building, or time to run the business, which I followed strictly. I also filled out "conflict of interest" forms every year, declaring the name of my side business, etc., declaring I won't take part of procurement decisions.
Now, I discovered that one department is, to no surprise, in need of my product. Its potentially a quite big sale, so not something I want to ignore...and for a product they've given up on finding, but...
Is it likely fire-able/illegal to send advertisements the place I work?