Viruses are also microscopic, but are not actually live cells. Viruses need to combine with a live cell where they act sort of like a parasite, taking over the cell and changing its nature and function to something harmful. They are likely to get into food in similar ways to bacteria and can affect any food type. They don't multiply in food they just use the food as a vehicle to get around.
Some of the viruses common to food borne illness in New Zealand include:
Metallic compounds are naturally present in many foods in low concentrations which are not harmful. But some excessive amounts get into foods via herbicidal, antifungal and insecticidal sprays of fruit and vegetables, plumbing pipes for drinking water reticulation or from ceramic glazing, tin can coatings or trade waste contaminated waters in which seafood are harvested.
Some metals which can become food contaminants in these ways include:
Some other food borne chemical contaminations include arsenic, selenium sodium nitrite, from meat pickling, algae toxins and some other pesticides. Your local Health Protection Officers from the Ministry of Health will periodically sample foods at the point of processing, and recreational waters, to test for harmful levels of these contaminants to ensure the Food Regulations (or new ANZFA regulations) are not breached.
To help prevent illness from chemicals and metals you must ensure that:
All the remaining sections of this text combine to show you how to prevent food borne illness. Contamination is an aspect of food safety that there is no excuse for. What is not already there naturally must not be allowed to get there, and what is there naturally must be controlled. Knowledge of the risks associated with different food types will help you decide how to treat each food item you deal with and prevent the three different types of contamination at all times.