What temperature do you wash laundry with hep b blood on? also what happens if i accidentally put a blood covered handkerchief (in a red bag) in with other items will it cross contaminate and infect others?

Any laundry detergent will instantly kill hepatitis B virus. Cross contamination cannot occur. Water tempreature makes no difference.

Very unlikely. Hepatitis B virus can survive in the environment for 7 or more days but is usually inactivated by household bleach. Transmission of Hep B virus requires a contact of nonintact skin, e.g., open wound or mucous membrane with blood, semen, or vaginal secretions. The virus is not transmitted by the fecal-oral route either.