6 Causes of food poisoning at home

What are the risks associated with the unsafe handling of food?   Food poisoning!  This is a significant risk because some of the illnesses from food poisoning can be pretty serious.  If you have ever had food poisoning, it is not pleasant at all.   Some food poisoning illnesses may involve hospitalisation, kidney failure and even death.

Common symptoms of food poisoning are diarrhoea, vomiting, stomach cramps, fever, nausea and aches.

Many of the foods we buy are not sterile.  They contain bacteria and other types of germs such as viruses and moulds.  Some of the bacteria in the food may be food poisoning bacteria.  Viruses such as norovirus cause food-borne illnesses.

Certain foods are more prone to become unsafe if not handled correctly.  These foods are meat products, dairy, eggs, cooked food, ready-to-eat meals, prepared salads and prepared fruits.

How you handle your food after you have purchased it will either keep it safe or make it unsafe.

Common causes of food poisoning at home

1. Food poisoning resulting from keeping food outside of safe temperatures

Food should either be stored below 5 degrees Celcius if chilled or above 63 degrees Celsius if kept hot.  The range between 5 and 63 degrees Celcius is referred to as “the danger zone”. Within this temperature range, food-poisoning bacteria grow rapidly.  Chilled food should be stored at a temperature of below 8 degrees, ideally below 5 degrees.  When food is held above 5 degrees for long periods of time, food-poisoning bacteria can grow.  Food poisoning bacteria is one of the main causes of food being unsafe.

Depending on the type of bacteria, it may take a few of these bacteria to make you ill or it may take a lot of them.  Because bacteria double rapidly if the food is within the danger zone, the numbers can grow to hundreds of thousands if not millions within a few hours.

Some of the food poisoning bacteria produce toxins in food if the food is stored within the danger zone.  These toxins can kill you or can make you very ill.

Your food may end up staying in the danger zone in various ways.  One way is carrying your food shopping around or leaving it in the boot of your car as you run errands.  This is worse when it is hot, e.g., during the summer months.  After food shopping, take your shopping home and store chilled foods in the fridge as soon as possible.

Your food can also stay in the danger zone after cooking as you wait for it to cool down.  The advice is to cool down your food within 2 hours and store it in the fridge.  If you cook a large amount of food like in batch cooking,  my tip for cooling down food quickly is to subdivide it into smaller quantities.  Another method is to place the pot in a cold-water bath ensuring no water gets into the food.  You can use a plugged sink or a bigger pot for the water bath.  The water bath speeds up the cooling process.

2. Introduction of food-poisoning bacteria from foods containing these bacteria in food that is ready to eat.

Some foods such as raw meat or raw fish naturally have food-poisoning bacteria in them.  These foods only become safe after they are thoroughly cooked.  If raw meat comes into contact with your ready-to-eat food, food poisoning bacteria can transfer from the raw meat to the ready-to-eat food.  The transfer of bacteria from one product or surface to another is called cross-contamination.  Raw meat can come into contact with your other food, in your shopping basket for instance.  If the pack of meat is leaking, the fluids can get into other food.

At home, leaking raw meat may contaminate foods in the fridge or contaminate your countertops or table.  When you store your raw meat in the fridge, ensure it is in a leak-proof container.  Also, do not store raw meat above cooked or ready-to-eat foods in the fridge. This ensures the meat doesn’t leak into other foods.  If meat juices leak onto the counter, clean the counter thoroughly and disinfect it.

Do not chop salad on the same chopping board or use the same knife you just used for raw meat.  This is one of the most common ways of getting food poisoning.  Use separate chopping boards for raw meat and ready-to-eat foods such as salads.  If you don’t have separate chopping boards, chop your salad first before chopping meat and always make sure your dishes are washed thoroughly.

3. Defrosting food at room temperature

Defrosting food at room temperature can make your food unsafe.  To ensure that food is not kept in the danger zone, it should be defrosted in the fridge.  Sometimes this may not be possible, and you may want to hurry the defrosting process.  The second-best option is to defrost in chilled water as this keeps the temperature of the product down and limits bacteria growth.  Ideally, plan ahead and start your defrosting process early.  If you are defrosting your meat in cold water, the water used for defrosting is likely to be contaminated with bacteria from the meat.  Treat it as such and ensure it doesn’t splash on surfaces and utensils.

4. Not cooking food thoroughly

Foods such as raw meat only become safe once cooked thoroughly.  Undercooking meat leaves some of the food-poisoning bacteria in the meat.  Always remember, raw meat carries food-poisoning bacteria.   The only way to make your meat safe is by cooking it thoroughly.  If cooking a joint of meat, a whole turkey or chicken, ensure it is cooked through to the bone.  Use a thermometer to check the temperature of the cooked meat.  The temperature should be above 75 degrees.  When taking temperature, probe the thickest part of the meat and push the probe to the core or near the bone.  If taking temperatures is not possible, cut up the meat into pieces just to ensure it is cooked through properly.  This will also save your energy bill.

5. Not washing hands before handling food

Hands can transfer food-poisoning bacteria to food.  Wash your hands before handling any food, or after using the toilet.  Bacteria is all around us, on door handles, on clothes, on food packaging and on surfaces.  We are constantly touching these surfaces.  This means at any given moment our hands have bacteria on them.  Some bacteria which may cause food poisoning actually live on our skin.  If these bacteria are transferred to food, this may lead to food poisoning. This is especially the case if the food is stored within the danger zone.

Not washing hands between handling raw meat and other food is also a common way of transferring food-poisoning bacteria from the meat to the other food.  Wash hands between handling different foods, and also after touching product packaging.  If you can avoid touching the food with your bare hands, even better.

Food poisoning-handling raw meat
handling food after handling raw meat may cause food poisoning

6. Eating food beyond its use-by date

Use by date means that the product should be used up until the date shown on the product. Use by means exactly what it says, use the product by the date on it.  A use-by date is different to a best-before date.  Use by date means the product may not be safe after the use by date.  Best before on the other hand means the quality of the product may not be the best, but the product is still safe to be eaten after the best-before date.  Food products that carry a use-by date tend to be products that also spoil quickly.  These foods include meat, ready-to-eat meals, prepared salads, soft cheese, pate, etc.  These types of products are normally stored chilled.  This slows down the growth of food-poisoning bacteria.

Eat your ham, your pate, and your brie within the use-by date.  Use by date is not only for controlling spoilage.  Remember that unspoilt food may be full of food-poisoning bacteria once it is beyond its use-by date.  It may smell and taste alright, but it will make you sick.  Food Standards Agency has provided a guide on the difference between best-before dates and use-by dates.