I totally agree with ger21,
Personally, I wouldn't worry too much about the formaldehyde if the shop is not a huge user. What you should be concerned about is the dust generated by any cutting/routing/drilling/sanding operations on MDF. That dust is
really fine and does your lungs no good.
A whole load of companies in the UK will not use MDF because the cost of effective dust extraction for small power tool tasks is huge if they wish to comply with insurance/ government safety obligations. In your own workshop, you can do what you want... but wearing a comfortable, convenient, positive pressure respirator/vizor will do you no harm.
BTW, if the vizor is scratched, and you cannot see clearly, you will not use it, so get a few spare polycarbonate windows.
Good health, and good luck,
Best wishes,
Martin