It is an offence to intentionally cause human biological material to come into contact with a person, or to threaten (by words or conduct) to cause human biological material to come into contact with a person [Criminal Law Consolidation Act 1935 (SA) s 20AB].
This could include spitting, throwing, or otherwise performing some action that may result in biological material coming into contact with a person.
The maximum penalty for an offence against s 20AB is imprisonment for 2 years, or 3 years if harm is caused to the victim.
A senior police officer may authorise the taking of a sample of blood from a person suspected of a prescribed serious offence (which includes an offence against s 20AB) if it is likely that their biological material came into contact with a police officer or other frontline emergency services or hospital worker [see Criminal Law (Forensic Procedures) Act 2007 (SA) s 20B]. The purpose of the blood sample is to test for communicable diseases the frontline worker may have been exposed to. Police must authorise the taking of a sample of blood if the frontline worker requests it [s 20B(3)] unless the suspect is a protected person (a child or someone lacking legal capacity) [s 20B(4)].