Food Safety Danger Zone

Food Safety Danger Zone
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Food safety danger zone means the chemical contaminants in foods which can be naturally occurring or added during processing. Harmful chemical compounds, at high levels, have been associated with acute cases of FBD (foodborne disease) and may be responsible for chronic diseases.

Sometimes a poisonous substance in food can be controlled (reduced to minimal risk) if the food is sufficiently washed or cooked. In the meantime, the best strategy is to keep hazardous substances out of the food by purchasing ingredients and raw materials from suppliers and knowing the conditions of production, harvest, processing and storage.

Consumer health hazards are increased when chemicals are not controlled or recommended usage rates are exceeded. The largest group of chemical compounds used in food processing is the category of food additives. They are all substances intentionally added to food, to modify its physical, chemical, biological or sensory characteristics, during manufacturing, processing, preparation, treatment, packaging, conditioning, storage, transport or handling.

Food safety danger zone – Additive

The intentional use of additives includes those used according to Good Manufacturing Practices, which can be used in sufficient quantity to achieve the desired effect, provided that the additive does not affect the identity of the food and its use does not result in deceptive practices. 

Food Safety Danger Zone
Food Safety Danger Zone

The addition of these substances may result in the additive itself or its derivatives becoming a component of the food. This does not include contaminants or substances that are incorporated into the food to maintain it or improve its nutritional properties. Additives are classified into the following functional categories:

  1. Defoamer
  2. Acidity regulator
  3. Anti-humectant
  4. Acidulant
  5. Antioxidant
  6. Emulsifier
  7. Colouring
  8. Flour improver
  9. Preservative
  10. Flavour enhancer
  11. Sweetener
  12. Chemical Ferment
  13. Thickener
  14. Gelling agent
  15. Firmness Agent
  16. Color Stabilizer
  17. Flavouring

Food industry technology

Any substance, excluding the equipment and utensils used in the preparation and/or conservation of a product, that is not consumed by itself as a food ingredient, but that is used intentionally in the preparation of raw materials, food or its ingredients, to achieve a technological purpose during treatment.

It must be removed from the food or its derivatives may be accepted in the final product. They are classified into the following functional categories:

  1. Catalyst
  2. Lubricant or modelling agent
  3. Biological ferment
  4. Nutrient for yeast
  5. Clarifying/filtration agent
  6. Clotting agent
  7. Solvent extraction and processing
  8. Flocculating agent
  9. Enzyme inhibiting agent before the bleaching stage
  10. Enzyme immobilizing agent
  11. Cooling/freezing agent
  12. Dust suppressant agent
  13. Degumming agent
  14. Enzyme
  15. Propellant gas, packaging gas

Chemical contamination of food can occur if

They are undesirable substances present in the food as a result of the operations carried out in the cultivation of vegetables, in the breeding of animals, in a zoo or phytosanitary treatments, or as a result of environmental contamination or equipment used in the conservation of the food. 

Heavy metals

Metals such as lead from pipes can contaminate food, causing heavy metal poisoning. Packaging material can also contaminate the product with these metals. In the US, in the past, there was concern about lead contamination from can amendments and polychlorinated biphenyls (PCBs) in food from cardboard packaging.

Food Safety Danger Zone
Food Safety Danger Zone

Those concerns abated with the removal of such compounds from food packaging production. However, that type of material is still used in other parts of the world.

Heavy metals and radioactive isotopes from the environment can also be found in food, usually carried by water. An example of this is the level of mercury in fish caught in lakes and rivers. 

Chemical pesticides

The production, distribution, sale and use of chemical pesticides (insecticides, rodenticides, fungicides, herbicides, plant regulators, exfoliants, dehydrators, etc.) must be highly controlled in food production. 

The use of pesticides must comply with specific limits regarding the mode and conditions of application, permitted concentrations, type of organisms against which the product must be used, use restrictions, and distribution requirements. Furthermore, each agricultural pesticide must be approved only for specific plantations. 

The use of any pesticide, even those used in a pest control program in the food industry, must strictly comply with the instructions and information on the label.


The increasing use of these chemicals in agriculture and animal production has been observed to increase the potential for chemical contamination of food produced throughout the world. These substances have a major impact on aquatic systems. When it rains, they are washed into rivers and lakes, contaminating fish and aquatic plants and the water supply. 

Drug Residues

Antibiotics and other drugs used in animals are also FBD-related hazards. In 1990, the US Department of Agriculture (USDA) tested 35,561 animal farms for drug residues and found unacceptable levels in 132 samples. The USDA also tested 9,132 samples of chicken meat and found unacceptable levels of residues in 12 of them. Drug residues in food can cause violent allergic reactions in sensitive individuals. 

Food Safety Danger Zone
Food Safety Danger Zone

Natural plant substances

Toxic plant products include solanine in potatoes, hemagglutinin and protease inhibitors in kidney beans and peas, cyanogens in fruit and phytoalexins in sweet potatoes and celery. Fortunately, several of these compounds are eliminated with the preparation methods. For example, solanine is removed when the green part of the potato skin is removed.

Cyanogen-containing fruit seeds and pits are generally discarded. Hemagglutinins and protease inhibitors in raw plant seeds are modified by moist heat cooking, ceasing to be harmful to health. Chemicals created during processing include those formed when meat is excessively grilled over charcoal and compounds formed when fat or oil is heated excessively and for a long time. 


Regarding adverse reactions to certain foods, about 1% of the population is allergic to components (generally proteins) found in food. Various types of food, such as milk, eggs, fish, seafood (mainly shrimp), legumes (peanuts), nuts and cereals, can cause allergic reactions. Other foods, such as citrus fruits, melon, banana, tomato, corn, barley, rice, and celery can cause allergic reactions in some sensitive individuals.

These reactions vary with the sensitivity of each person. Some reactions may be mild (eg, watery eyes, nasal discharge, headache). But if susceptible people consume an allergenic food, they can go into severe anaphylactic shock within a few minutes. Food ingredients recognized as allergens must be indicated on the label, as is the case with gluten.

Lack of access to nutritious food is called

Nutrition (diet), or lack of it, is a health problem. People’s health status is particularly important in disease prevention and depends in part on a nutritionally balanced diet. If this does not happen, the quality and expectancy of life decrease. Both macro and micronutrients are necessary to promote and maintain human health.

In many developing countries, the lack of adequate food supply contributes to malnutrition and decreases the general health status of the population, mainly infants and children. As a consequence, a large part of the population is susceptible to infections and other diseases.

Nutritional hazards in food products are as follows:

  1. Nutritional deficiency can cause illness and even death in infants, the elderly and very sick individuals. 
  2. Antinutritive factors such as phytates in green leafy vegetables and trypsin inhibitors in legumes and soybeans should be considered in the production and preparation of feed.
  3. The destruction and unnecessary loss of nutrients occurs when foods are processed for very long periods and are stored improperly. The nutrient most susceptible to destruction is ascorbic acid (vitamin C). The loss of said element in cooked vegetables is high if the food is kept in thermal balconies for a long time.

What is an example of a natural food toxin?

Fish and shellfish may contain some of the toxins known to have the potential to cause human disease. These toxins are not affected by cooking and there are no antidotes or antitoxins to reduce their toxicity.

Food Safety Danger Zone
Food Safety Danger Zone

The best control is to obtain fish and shellfish certified by a supplier with HACCP guidelines that have been caught in safe waters (areas under surveillance) and the storage of these products is done in conditions that do not allow deterioration.

Many shellfish poisonings are caused by a group of toxins produced in planktonic algae (dinoflagellates, in most cases). The toxin accumulates and is sometimes caused by the acute disease of shellfish.

  • Paralytic shellfish poisoning (PSP), 
  • Diarrheal shellfish poisoning (DSP), 
  • Neurotoxic shellfish poisoning (NSP), and 
  • Amnestic shellfish poisoning (ASP). 

Nature of diseases

Ingestion of contaminated shellfish results in a variety of symptoms, depending on the toxin(s) present, its concentration in the shellfish, and the amount of contaminated shellfish ingested. In the case of PSP, the effects are predominantly neurological and include tingling, burning, numbness, drowsiness, incoherent speech, and respiratory paralysis. 

The symptoms of DSP, NSP, and ASP are not well characterized. DSP presents mainly as a mild gastrointestinal disorder, that is, nausea, vomiting, diarrhoea, and abdominal pain accompanied by chills, headache, and fever. 

Neurological and gastrointestinal symptoms characterize NSP, including tingling and numbness of the lips, tongue, and throat, muscle pain, dizziness, reversed wind chill, diarrhoea, and vomiting. ASP is characterized by gastrointestinal disorders (vomiting, diarrhoea, and abdominal pain) and neurological problems (confusion, memory loss, disorientation, apprehension, and coma).

Paralytic shellfish poisoning (PSP)

PSP: Symptoms of illness can develop rapidly, 30 minutes to 2 hours after shellfish ingestion, depending on the amount of toxin consumed. In severe cases, respiratory paralysis is common, and death occurs if there is no respiratory support.

In severe cases, respiratory paralysis is common, and death occurs without respiratory support. When it is applied within 12 hours of exposure, recovery is usually complete, with no side effects. In rare cases, due to the hypotensive action of the toxin, death may occur due to cardiovascular collapse, despite respiratory support.

Cardiovascular symptoms include arrhythmia, bradycardia or tachycardia, and low blood pressure. Ciguatera poisoning is usually self-limiting, with signs of poisoning lasting a few days. However, in severe cases, neurological symptoms can persist for several weeks or even months. In some isolated cases, these symptoms lasted for several years.

In other cases, patients showed recurrence of neurological symptoms months or years after recovery. Those cases were related to diet changes and alcohol consumption. The incidence of death is low and is a consequence of respiratory or cardiac arrest.

Histamine poisoning

Scombrotoxin poisoning from fish of the family Scombridae (also called histamine poisoning). It is caused by the ingestion of food containing high levels (greater than 100 ppm) of histamine and possibly other vasoactive amines and their compounds.

Histamine and other toxic amines are formed by the development of certain bacteria and the subsequent action of enzymes produced by them, which decarboxylate histidine and other amino acids, which are naturally present in certain foods.

This can occur during the production of foods such as Swiss-type cheese (tyrosine for tyramine) or due to the deterioration of foods such as fish, mainly tuna or sea dorado (histidine for histamine). 


It results from the intake of aflatoxins in contaminated food. Aflatoxins are a group of structurally related toxic compounds produced by certain strains of the fungus. Under favourable conditions of temperature and humidity, these fungi develop in certain foods and food products, resulting in the production of aflatoxins. 

The worst contamination was found in tree nuts, peanuts, and other oilseeds, including cotton and corn. The aflatoxins of most interest are designated B1, B2, G1, and G2. These toxins are generally found together in various foods and food products and various proportions.

However, aflatoxin B1 is predominant and most toxic. A derivative of this toxin is M1, found in milk. This mycotoxin is present in milk as a consequence of the consumption of feed containing aflatoxins B and G.milho. 

Nature of the disease

Aflatoxins cause acute necrosis, cirrhosis and carcinoma of the liver in various animal species. There are no animal species resistant to the acute toxic effects of aflatoxins. In conclusion, it seems reasonable to consider that human beings can be affected in the same way. Animal species respond differently in terms of susceptibility to acute or chronic aflatoxin poisoning.

Environmental factors, level and duration of exposure, age, health and nutritional status can influence toxicity. Aflatoxin B1 is a highly potent carcinogen in many species, including primates, birds, fish, and rodents. In all species, the liver is the main organ affected by acute injury. Metabolism plays an important role in determining the toxicity of aflatoxin B1.

Studies have shown that this toxin requires metabolic activation to exert its carcinogenic effect, and these can be modified by the induction or inhibition of the oxidase system.

Name of the acute disease

Mushroom poisoning is caused by the consumption of superior mushrooms of different species (columella, toad hat [amanita muscaria]) raw or cooked. The term “toad hat” (from the German Todesstuhl, faeces of death) is often given to toxic fungi. It is not easy for individuals who are not specialists in fungal identification to identify and distinguish toxic from non-toxic species.

Toxins are naturally produced by fungi and each specimen of a toxic species can be considered poisonous. Most mushrooms are not rendered toxic by cooking, canning, freezing, or other processing methods. So the only method of avoiding intoxication is by avoiding consumption.

Mushroom poisonings are generally acute and manifest with various symptoms, leading to different diagnoses, depending on the amount consumed. Due to the unknown chemical structure of various fungal toxins, precise identification of the toxic species is difficult or impossible. Poisonous mushrooms are classified by their physiological effects.

  • Protoplasmic toxins, cause cell destruction followed by organ failure.
  • Neurotoxins, whose compounds cause neurological symptoms, such as heavy perspiration, coma, seizures, hallucinations, excitement, depression, etc.
  • Gastrointestinal irritant toxins, cause nausea, vomiting, abdominal pain, and diarrhoea.
  • Disulfide-type toxins, are generally non-toxic and produce no symptoms unless alcohol is ingested within 72 hours after ingestion of the fungus. In that case, an acute toxic syndrome occurs.

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