Is it permissible to give the expiatory food to a poor sanitation worker? Is it necessary to verify if he is a Muslim? And is it permissible to give the expiation as money to a charity?

Expiations (Kaffarat) are specifically for the poor and the needy. A sanitation worker is not considered needy or poor merely by virtue of their job; rather, this is determined by their salary and their level of need. If their salary is insufficient for their basic needs, then they are needy; otherwise, no. It is not permissible to give expiation to a non-believer according to the majority of scholars. The person paying the expiation must verify that the recipient is among those eligible to receive it. There is no harm in authorizing trustworthy charitable organizations to distribute expiations.