Envis Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Wednesday, July 24, 2024

Food Hygiene


Contaminated food represents one of the greatest health risks to a population and is a leading cause of disease outbreaks and transmission. Food that is kept too long can go bad and often contains toxic chemicals or pathogens, and food-stuffs that are eaten raw, such as fruits or vegetables, can become contaminated by dirty hands, unclean water or flies and other such vectors. Improperly prepared food can also cause chemical poisoning. Half cooked or over cooked food for example hard boiled eggs and over cooked meat are bad for health.


To promote good health, therefore, food should be properly stored and prepared. 


Ways in which communities can prevent health risks from food are discussed below: 

Food preparation in the home:


As most families eat food that is prepared at home, it is important that families understand the principles of basic hygiene and know how to prepare food safely:


  •  Before preparing food hands should be washed with soap or ash.



  •  Raw fruit and vegetables should not be eaten unless they are first peeled or washed with clean water. 


  •  It is also important to cook food properly, particularly meat. Both cattle and pigs host tapeworms that can be transferred to humans through improperly cooked meat; for this reason, raw meat should never be eaten. 


  •  Eggs, too, must be cooked properly before eating, since they may contain salmonella, a virulent pathogen. 


  •  The kitchen itself should be kept clean and waste food disposed off carefully to avoid attracting vermin, such as rats and mice that may transmit disease. 


  •  Keeping food preparation surfaces clean is critical, because harmful organisms can grow on these surfaces and contaminate food. 


  •  Fresh meat should be cooked and eaten on the same day, unless it can be stored in a refrigerator; if not, it should be thrown away immediately.


  •  Cooked food should be eaten while it is still hot and should not be left to stand at room temperature for long periods of time, since this provides a good environment for pathogens to grow. 


  •  Food that is ready to eat should be covered to keep off flies and should be thrown away if not eaten within 12 – 16 hours. 


  •  If food must be stored after cooking, it should be kept covered and in a cool place, such as a refrigerator and if a refrigerator is not available, food can be stored on ice blocks or in a preservative such as pickling vinegar or salt. 


  •  Food that is already prepared, or food that is to be eaten raw, must not come into contact with raw meat as this may contain pathogens that can contaminate the other foods (particularly if slaughtering was not carried out hygienically).


Hotels and Restaurants:


In many urban centres food is bought and consumed at eating-houses (cafes, restaurants or canteens). If basic health and safety rules for storing, preparing and handling food are not followed in the eating-houses; these places will represent a health hazard for the customers and may cause serious disease outbreaks. The most important aspects of food hygiene in these establishments relate to sanitation, water supply and personal cleanliness:


  •  Eating-houses should have clean water for washing and drinking, and separate sanitation facilities, away from the kitchen area, for customers, cooks and food-handlers.


  •  The staff should have clean uniforms each day and have regular medical check-ups.


  •  The cooks, chefs and waiters should be the most particular in their own personal hygiene so as to prevent any contamination of food handled by them.


  •  Food to be served should be prepared fresh always and any that is spilled or not used should be disposed off.


  •  The kitchens and eating areas must be kept clean and free of vermin and insects.


  •  Eating-houses should also be well-ventilated, with adequate lighting.

Street food-vendors:


Street food-vendors are common in urban and peri-urban areas, but they also operate in rural areas, particularly if there is a market or community fair. Although people enjoy food from these vendors, in many cases the food is of poor quality and it represents a serious health risk. In part, this is because the street vendors have little or no access to safe water supplies or sanitation facilities, and they commonly cook and handle food with dirty hands. Raw foodstuffs, too, cannot be kept in safe storage places and are easily contaminated by vermin and insects. Moreover, the street vendors often keep cooked food at ambient (environmental) temperatures for prolonged periods of time and may heat the food only slightly before serving. All these factors may make the food from street vendors dangerous.

Promoting nutrition:


A healthy and well-balanced diet is essential for good health. When there is not enough food, or if the diet does not contain the right balance of food-stuffs, people become more prone to illness and may become undernourished or malnourished. Children, in particular, are vulnerable to poor nutrition. Undernourishment and malnourishment can lower their resistance and make them more likely to suffer from infectious diseases. Often, children will eat only small amounts of food if it is spicy, even if it is nutritious, and it is important to make children's food less spicy than adult food. Also, because their stomachs are small, children can eat only small portions and need to be fed more frequently than healthy adults. It is also important that children are fed not just foods high in starch or carbohydrate (for instance rice). Although these foods can quickly make a child feel full, he or she may become malnourished if other key foodstuffs are not eaten.


  •  A well-balanced diet usually has a mixture of food:


  •  Proteins (for example beans, peas, meat, fish or eggs).


  •  Carbohydrates (such as maize, potatoes, cassava, rice and many other staple foods).


  •  Vitamins (such as vegetables, fish, fruits or milk).


  •  Fats or oils (such as cooking oil).


Sometimes not all these foods are available and it is important that community members ask health workers how to make best use of available foods for a balanced diet. In many situations, nutrition can be improved by changing agricultural or gardening practices. Often, even small plots of land can provide nutritious food provided that the right crops are grown. Health workers or agricultural extension workers can be asked for advice about which crops to grow to provide community members with well-balanced diets. 




Everybody at one time or another has had the experience of eating food and sometime later becoming sick. This is called food poisoning. The symptoms may include:


  • Nausea


  • Vomiting


  • Stomach pains


  • Diarrhoea


  • Feeling weak


  • Fever or chills/sweating


  • Headache


Food poisoning can be caused by eating food contaminated with bacteria, viruses, chemicals or poisonous metals such as lead or cadmium. Most food poisoning, however, is caused by bacteria and because of this, only bacteria will be discussed in this section. Food which has become contaminated with harmful bacteria does not always taste bad. Most of the time it looks smells and tastes like it normally does. Some food poisoning diseases are more common than others. For example, disease caused by Staphylococcus aureus occurs a lot more often than disease caused by Clostridium botulinum.


Some foods cause food poisoning more than others and need to be cooked properly and/or kept in the refrigerator. These include chicken, meat, seafood, eggs, cooked rice, ham, salami, milk and all dairy foods. It is important chicken is cooked properly to the bone and then kept in the fridge for no more than 2 days. If reheating chicken, or left-overs, make sure it is steaming hot and only reheat it once



It is important to remember that the same food handling practices are used to prevent all food poisoning diseases. Washing your hands with soap and drying them on a paper towel or with a clean cloth is the best way to stop the spread of bad bacteria.




Food can become contaminated with disease-causing bacteria anywhere the food is handled or stored. These places include:


  • In a factory where it is processed ready for sale


  • In a truck in which it is taken from the factory to the shop


  • In a shop


  • In a food outlet such as a school canteen or take-away shop


  • between the shop and home


  • In a home


Most food has to be prepared in some way before it is eaten. During this preparation the food is handled by people. There are many ways in which unhygienic practices can cause food poisoning bacteria to be deposited on the food while it is being handled. Some examples are:


Leaving food uncovered. Pets, flies, cockroaches and other insects carry germs, including food poisoning bacteria, which contaminate the food


Touching parts of the body while handling food. While preparing food a food handler might scratch a pimple, touch a sore, push back hair, scratch an ear or rub or pick the nose. Every one of these activities contaminates the fingers with bacteria. If the person's hands are not washed before handling food again, these bacteria will be passed to the food.





  • Keep clean Wash your hands with soap before handling food and often during food preparation Wash your hands with soap after using the toilets Wash and sanitize all surfaces and equipment used for food preparation Protect kitchen areas and food from insects, pests and other animals


  • Separate raw and cooked Separate raw meat, poultry and seafood from other foods Use separate equipment and utensils such as knives and cutting boards for handling raw foods Store food in containers to avoid contact between raw and prepared foods


  • Cook thoroughly Cook food thoroughly, especially meat, poultry, eggs and seafood Bring foods like soups and stews to boiling to make sure that they have reached 70°C. For meat and poultry, make sure that juices are clear, not pink. Ideally, use a thermometer Reheat cooked food thoroughly Avoid overcooking when frying, grilling or baking food as this may produce toxic chemicals


  • Keep food at safe temperatures Do not leave cooked food at room temperature for more than 2 hours Refrigerate promptly all cooked and perishable food (preferably below 5°C) Keep cooked food piping hot (more than 60°C) prior to serving Do not store food too long even in the refrigerator Do not thaw frozen food at room


  • Use safe water and raw materials Use safe water or treat it to make it safe Select fresh and wholesome foods Choose foods processed for safety, such as pasteurized milk Wash fruits and vegetables, especially if eaten raw Do not use food beyond its expiry date.





  • Give your baby only breast milk for the first 6 months of life From birth to 6 months of age your baby should receive only breast milk, day and night Breast feed your baby whenever the baby feels hungry


  • Eat a variety of foods Eat a combination of different foods: staple foods, legumes, vegetables, fruits and foods from animals


  • Eat plenty of vegetables and fruits Consume a wide variety of vegetables and fruits (more than 400 g per day) Eat raw vegetables and fruits as snacks instead of snacks that are high in sugars or fat When cooking vegetables and fruits, avoid overcooking as this can lead to loss of important vitamins Canned or dried vegetables and fruits may be used, but choose varieties without added salt or sugars


  • Eat moderate amounts of fats and oils Choose unsaturated vegetable oils (e.g. olive, soy, sunflower, corn) rather than animal fats or oils high in saturated fats (e.g. coconut and palm oil) Choose white meat (e.g. poultry) and fish that are generally low in fats rather than red meat Limit consumption of processed meats and luncheon meats that are high in fat and salts Use low- or reduced-fat milk and dairy products, where possible Avoid processed, baked, and fried foods that contain industrial trans fatty acids


  • Eat less salt and sugars Cook and prepare foods with as little salt as possible Avoid foods with high salt content Limit the intake of soft drinks and fruit drinks sweetened with sugars Choose fresh fruits for snacks instead of sweet foods and confectionery (e.g. cookies and cakes)





Every day, people all over the world get sick from the food they eat. This sickness is called food borne disease and can be caused by dangerous microorganisms. Eating fruits and vegetables contaminated with dangerous microorganisms is a source of food borne disease. Preventing microbial contamination is the best way to prevent disease and improve your health and that of your family and community.


Microorganisms are very small living things. In fact, they are so small that they cannot be seen with the naked eye.


There are three different types of microorganisms: the good, the bad and the dangerous.


  • Good microorganisms are useful. They are used to Make food and drinks (e.g. cheese, yoghurt, beer and wine) Make medicine (e.g. penicillin) ; and Help digest the food you eat.


  • Bad microorganisms, or spoilage microorganisms, usually do not make people sick. However, they cause food to look, smell and taste bad.


  • Dangerous microorganisms make people sick and can even cause death. Bacteria, viruses, yeasts, moulds and parasites are all microorganisms. Most dangerous microorganisms do not change the appearance of the food, so you usually can’t tell that the food is contaminated with dangerous microorganisms by just looking, smelling or tasting it.


The most common symptoms of food borne disease are:


  • Stomach pains


  • Vomiting


  • Diarrhoea


The symptoms depend on the cause of the disease. Symptoms may occur very quickly after eating the food, or may take days or even weeks to appear. For most food borne diseases, symptoms occur 24 -72 hours after the food has been eaten. It is estimated that 3% of food borne disease cases can lead to long-term health problems. Very severe diseases, including arthritis and neurological disorders can be caused by contaminated food. Some food borne diseases can be transferred from person to person. Caregivers can become sick from family members with a food borne disease. For infants, the sick people, pregnant women and the elderly, the consequences of food borne disease are usually more severe and more often fatal.



Advice on treatment of food borne disease differs between countries and should be adapted to the local region. However, as a general rule, one should drink plenty of fluids to maintain hydration during diarrhea and seek medical advice when bowel movements are very frequent, very watery or contain blood, or when symptoms last beyond 3 days.


Food safety Key facts


  • Access to sufficient amounts of safe and nutritious food is key to sustaining life and promoting good health.
  • Unsafe food containing harmful bacteria, viruses, parasites or chemical substances, causes more than 200 diseases – ranging from diarrhoea to cancers.
  • An estimated 600 million – almost 1 in 10 people in the world – fall ill after eating contaminated food and 420 000 die every year, resulting in the loss of 33 million healthy life years (DALYs).
  • Children under 5 years of age carry 40% of the foodborne disease burden, with 125 000 deaths every year.
  • Diarrhoeal diseases are the most common illnesses resulting from the consumption of contaminated food, causing 550 million people to fall ill and 230 000 deaths every year.
  • Food safety, nutrition and food security are inextricably linked. Unsafe food creates a vicious cycle of disease and malnutrition, particularly affecting infants, young children, elderly and the sick.
  • Foodborne diseases impede socioeconomic development by straining health care systems, and harming national economies, tourism and trade.
  • Food supply chains now cross multiple national borders. Good collaboration between governments, producers and consumers helps ensure food safety.

Source : WHO Updated on 23rd January, 2019


 Did you Know that Superbugs can be found in food?


Source : WHO, Updated on 10th May, 2018