Table 2

Type Description/examples
General Usually insoluble pigmented matter.
Oily Fats, waxes, cosmetics often containing pigments and other components.
Protein Blood, meat products, milk, egg. Severely affected by excess heat.
Body Urine, faeces, vomit, perspiration and other body exudations (often greasy).
Metal Iron (Rust), magnesium as well as other metal ions and metal oxides.
Bacteria Various types.