Final answer:
The three types of contaminants that threaten food safety are biological, such as bacteria and viruses; chemical, such as agrochemicals and environmental contaminants; and physical, such as objects like metal shards.
Step-by-step explanation:
The three types of contaminants that threaten food safety are: a) Biological, chemical, physical. Biological contaminants include various microorganisms, such as bacteria, viruses, parasites, and prions.
Out of these, Norovirus, Salmonella, Clostridium perfringens, and Campylobacter are the top pathogens causing foodborne illnesses in the United States.
Chemical contaminants can be further divided into agrochemicals and environmental contaminants. These substances can enter the food supply through various sources in the environment and are of concern as their impact on health may only become apparent after prolonged exposure at low levels.
Physical contaminants are objects such as metal shards, glass fragments, or pieces of plastic that may inadvertently end up in food during processing or preparation, creating an immediate danger to health if ingested.