All Hazards that the HACCP principles cover can be classed into three categories: biological, physical and chemical.
Biological Hazards: include hazards from pathogens such as bacteria, mould, viruses and yeasts. Bacteria such as Salmonella and E-coli are present in many inputs and need to be managed carefully.
Physical Hazards: include foreign matter such as glass, metal, wood and plastic being left in food from the production process.
Chemical Hazards: can be caused through the misuse of antibiotics, contamination of sanitizers or cleaning agents, or environmental contamination from hydraulic fluids.