These conditions are necessary for the growth of bacteria: food, acidity, temperature, time, oxygen, and moisture. What term is often used for these conditions?

The acronym FAT TOM refers to the conditions that are necessary for bacteria to grow. All of these conditions are present in TCS foods, except for time and temperature. You need to control time and temperature to prevent the bacteria from growing.
- Food: Bacteria can survive by consuming many of the same foods that we eat. Even a small drop of fluids or food particles on a countertop or cooking utensil is enough for bacteria to reproduce to unsafe levels.
- Acidity: This is measured with the pH scale which ranges from 0 to 14, with 7 being neutral. A lower number is acidic and a higher number is the opposite - alkaline. Different types of bacteria prefer different levels of acidity. But no bacteria can survive in very high or very low numbers of pH. This is why pickled foods can be preserved for long periods of time - the acidity is too high.
- Temperature: Bacteria reproduce very slowly in temperatures below 41°F and stop completely at freezing temperatures. Also, they reproduce very slowly at temperatures above 135°F and are killed at even higher temperatures. This is why we hold foods below 41°F or above 135°F.
- Time: Bacteria need time to reproduce. But they can reproduce very quickly if all of the other conditions are present. This is why we limit the time that food is allowed to remain in the Temperature Danger Zone of 41°F to 135°F.
- Oxygen: Like us, bacteria also need oxygen to survive and reproduce. But bacteria are able to utilize oxygen even underwater or submerged fluids. Some foods are stored in ROP (Reduced Oxygen Packaging) and this can preserve them longer. Ever wonder why a bag of chips is filled with air or why some containers pop or hiss when opened? This is because the oxygen has been removed and replaced with carbon dioxide. Most bacteria cannot reproduce in these conditions.
- Moisture: Bacteria need moisture to thrive and reproduce. This is why foods with little or no moisture (such as bread or crackers) are not TCS foods. Also, dehydrating foods (such as jerky or fruits) can be preserved for much longer.