All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
If you are the only one who knows about the medical error of your boss and his negligence, or you are the only one who can change this evil, then it is incumbent on you to forbid him from such negligence regarding asepsis. If he does not comply, then you should report him to his superiors who can prevent him from negligence; this is with the condition that no graver harm results from doing that.
An-Nawawi said regarding the ruling on forbidding evil, "...it may be deemed obligatory if the person is the only one who knows about this evil or the only one who can remove it..." [Sharh An-Nawawi ʻala Muslim]
Al-Aadaab Ash-Sharʻiyyah wa Al-Minah Al-Marʻiyyah reads, "Al-Qaadhi and others held that a person should start with the easiest means; if the evil is not eliminated by the easiest means of forbidding the evil, then he should opt for a harsher manner, and so on. If it proves to be ineffective in eliminating the evil, then he should report the evil to the ruler (concerned authority) from the start, as long as he does not fear his injustice in this matter."
Allah knows best.