Course:FNH200/Lessons/Lesson 04

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Food Standards, Regulations and Guides - Food Additives

This lesson will introduce you to "standards of identity" of foods and the need for regulations, standards and quality grades for foods, as well as the major governmental agencies that have a role in regulating the safety and quality of the food supply. You will learn about the Food and Drugs Act and Regulations of Canada, and the regulations that govern labelling and advertising as they apply to food. We will also discuss regulations governing grade standards for various food commodities that are administered by the Canadian Food Inspection Agency.

At one time or another, most people have been in a conversation where food additives have been the topic of discussion. Few people know what food additives are, what their purpose is, and what regulations govern their use. In this lesson we discuss and compare the Canadian and United States definitions of a food additive. We also discuss the classes of food additives and their functional properties in food systems. We review Canadian labelling requirements as they pertain to food additives and discuss the concepts employed in the evaluation of safety of food additives. We end the lesson with a discussion of aspartame and nitrites as examples of food additives that have generated much controversy in the recent past.

Objectives After completing this lesson, you will be able to:

  • describe the regulations and agencies that are in place to ensure the quality and safety of the Canadian food supply.
  • define what a food additive is
  • interpret the function of food additives that are listed on the labels of ingredients of food you consume
  • explain the basis upon which safety of food additives is determined; and
  • articulate your set of values as they pertain to the use of food additives in foods

Required Readings
Health Canada, Food program: Safety of Aspartame (
From Lesson 3: Kroger, M, Meister, K. and Kava, R. 2006. Low-calorie sweeteners and other sugar substitutes: A review of the safety issues. Comprehensive Reviews in Food Science and Food Safety 5: 35-47 (read esp pp. 37-39).
Hotchkiss, J.H. and Cassens, R.G. 1987 [April]. Nitrate, nitrite and nitroso compounds in foods (A scientific status summary). Food Technology, 41(4):127-136.
Health Canada. 2006. Food Additive Dictionary. Publication H49-10/1996E. Ottawa: Health Canada.

Canadian Government Agencies

In order to ensure that the food we purchase and consume is safe and within certain preset limits of quality, government promulgated standards, regulations and grades are in place to protect the consumer. The Department of Justice Canada is responsible for maintaining the Consolidated Statutes and Regulations for the Government of Canada, including the Food and Drugs Act and Food and Drug Regulations.

The Food and Drugs Act of Canada is administered by the Health Products and Food Branch of Health Canada, whereas inspections for compliance are enforced by the Canadian Food Inspection Agency. Several other government agencies work together to ensure the safety and quality of foods produced and/or consumed in Canada.

Health Canada: Health Products & Food Branch

Canadian Food Inspection Agency

  • food processing plant inspection
  • regulatory aspects of food safety
  • grade standards for agricultural produce, meats, dairy products, eggs, fish and seafood
  • meat, poultry, fish processing plant inspection
  • fruit and vegetable processing plant inspection
  • labelling and packaging regulations
  • advertising regulations

Industry Canada

  • weights and measures regulations

British Columbia Ministry of Health

  • public health inspection of retail stores and food service establishments
  • inspection of provincially inspected meat processing plants and dairy processing plants


  • public health inspection of retail stores and food service establishments

The Food and Drugs Act

Sections 3, 4, 5, and 7 of the Food and Drugs Act form the foundation of the consumer protection laws. Excerpts of the Act are shown on the right to give you an idea of the nature of the regulations.

It is interesting to note that Section 3 of the Food and Drugs Act prohibits the advertising to the general public of any food, drug, cosmetic or device for the treatment, prevention or cure of any of the diseases listed on Schedule A of the Food and Drugs Act. This section of the Act also prohibits the sale of a food, drug, cosmetic or device that is labeled in this manner.

In the light of recent trends and the demand for natural health products, functional foods and nutraceuticals, the House of Commons Standing Committee on Health mandated an External Working Group which is presently considering what revisions may be needed to this section of the Act. Box 4.1 Sections 3, 4, 5 and 7 of The Food and Drugs Act of Canada, that are the foundation of consumer protection laws.

How Are Regulations Established?

The Food Protection laws, in Canada, are wide in scope and major changes in the regulations embodied within the Food and Drugs Act are made after extensive consultation. We will discuss this consultation process when we deal with the section on Food Irradiation.

Rapid changes can also be made to the regulations such as in the case of delisting a food additive or other substance permitted in food when new evidence arises concerning issues of safety of a particular substance. Such was the case when the non-caloric sweeteners cyclamate and saccharin were banned. The regulations can be amended by authority of the Governor in Council. As noted on Table 4.1, regulations about labelling, advertising and claims about food are administered by the Canadian Food Inspection Agency (CFIA):

CFIA deals with food labelling, advertising and claims about food. Administers the labelling, packaging and advertising regulations under the Consumer Packaging and Labelling Act and Regulations and the Food and Drugs Act and Regulations. The CFIA also reviews all advertisements, on Canadian radio and television, making claims about foods. Weights and measures are regulated by "Industry Canada" specifically by a department known as "Measurement Canada". Inspection and enforcement of weight and measure related issues for foods are conducted by the Canadian Food Inspection Agency (CFIA)

Food Labelling Requirements

Labelling information required on pre-packaged food products, from domestic food processors or imported products, is based on the Consumer Packaging and Labelling Act and Regulations and can be found in the 2003 Guide to Food Labelling and Advertising at the CFIA website. The Basic Labelling requirements are described at:
Summarizing the information, a label should include the following:

  • Common name of the food. The common name is the name prescribed in the Food and Drugs Regulations. In the absence of a prescribed name, the name by which the food is commonly known is used.
  • Net quantity of the food
  • Name and address of the person responsible for the product
  • List of ingredients in descending order of proportion
  • The Nutrition Facts Table will show the Calories, the amount of fat, saturated and trans fats, cholesterol, sodium, carbohydrate, fiber, sugars, protein, calcium, iron and Vitamins A and C in a specified amount of food. Nutrition facts regulations apply to all pre-packaged foods with some exemptions (e.g fresh fruit and vegetables, raw single ingredient meat and poultry that are not ground, raw fish or seafood, alcoholic beverages).
  • Durable life date and storage instructions as required. This is required for foods with a storage life of 90 days of less. Durable life is the period of time, beginning on the day on which the pre-packaged product is packaged for retail sale, during which a product stored under prescribed conditions will retain, without appreciable deterioration, its normal wholesomeness, palatability and nutritional value and any other qualities claimed for it by the manufacturer. Products that have passed the durable life date and that have been stored under prescribed conditions are still safe to eat but the quality (appearance, flavour, nutritional value) may have deteriorated.
  • Bilingual labelling - All mandatory information on food labels must be shown in both official languages, i.e., French and English.

Additional Labelling Requirements

Other mandatory information may be required for certain foods:

  •  % alcohol for alcoholic beverages
  •  % milk fat for some dairy products
  • declaration of aspartame

Nutrient content claims and diet-related health claims, if made, must adhere to the stated criteria.

Energy and Calorie Claims

Do you know what it means when a food is labeled "free" or "light" in energy?
Find the answers here:

Specific Nutrient Content Claims

Check out the information presented here, using fat as an example,

What are the differences between 'Free of Fat' and 'Low in Fat'?

Disease Risk Reduction Claims

Currently, there are 5 disease risk reduction claims allowed in Canada:

A diet low in saturated and trans fats reduces risk of heart disease
A diet with adequate calcium and Vitamin D, and regular physical activity, reduces risk of osteoporosis
A diet rich in vegetables and fruit reduces risk of some types of cancer
A diet low in sodium and high in potassium reduces risk of high blood pressure
Does not promote tooth decay

Recommended Readings: To make these claims, food must meet criteria outlined here:

ACTIVITY Look at labels on a number of food products in your refrigerator and in your cupboards. Is the required information present? Look for the durable life date on packaged perishable food products (e.g. pasteurized milk, yogurt, cottage cheese, bread, refrigerated cured meats-frankfurters & bacon, etc).
Look for "health claims" in food products (breakfast cereals, orange juice, etc). Do these claims comply with Canadian regulations?

Standards of Food Identity and Composition

The Food and Drug Regulations contain descriptions of certain foods that specify, for example, what is allowed in those foods as ingredients. These descriptions are standards of identity and composition that have to be met for a food to be legally called by the name in the standard. The foods are referred to as "standardized foods". Examples of standardized foods include bread, milk, cheese, orange juice, sausage, jam, wine, beer, vinegar and salt. Foods that do not have a standard of identity are referred to as "unstandardized foods". Snack foods like potato chips, various bakery items such as rolls, donuts and cakes, yogurt, and pizza are examples of unstandardized foods.

Standards of food identity and composition are defined in the Food Regulations of the Food and Drugs Act of Canada.

Please bookmark the link for the Food and Drug Regulations of The Food and Drugs Act of Canada:,_c._870/

Note the following:

An identity standard is one that states what the food shall be and defines a food or ingredient. Compositional standards list the mandatory and permitted ingredients in foods.

There are standards of identity or composition for over 300 foods in the Food Regulations in Canada. They are classified within 28 divisions.

ACTIVITY: Can you identify the division number that regulates Dairy products, Food additives, Cocoa & chocolate products?

For example, Division 13 regulates "Grain and Bakery products". In this division, the standards of identity and composition for white wheat flour and bread can be found.

Food Grades Standards

Food grades standards are administered by the CFIA under the Canadian Agricultural Products Standards Act and the Meat Inspection Act, the regulations for which are described at the Justice Canada website. The agency which ensures that the standards and regulations are complied with is the Canadian Food Inspection Agency. Here is a list of some of the regulations:

  • Dairy Products Regulations
  • Egg Regulations
  • Fresh Fruit and Vegetable Regulations
  • Honey Regulations
  • Livestock and Poultry Carcass Grading Regulations
  • Maple Products Regulations
  • Processed Egg Regulations
  • Processed Products Regulations

Lesson 4 Activity #1:

Visit the Canada Agricultural Products Act at the Department of Justice Canada website:

New updated link as of March 7, 2016:

Click on Maple Products Regulations and then select: PART I: "GRADES AND GRADING" and SCHEDULE I. Read through the description and answer the following questions:

How many grades exist for maple syrup? what are they named?
Describe the major attributes that distinguish the first (top) grade and second grade.
What are the basic requirements for maple syrup to be graded?

Now select "Egg Regulations" and scan through the information to answer the following

How many grades exist for eggs? what are they named?
What are the basic requirements for eggs to be graded?
Which grade of eggs is further designated by size?
Which grades are shown on a label with a "maple leaf" design?
Which grades are sent to registered processed egg stations?
Take a look at an egg carton in your fridge or in the supermarket. Can you find the required information about the grade? size?

Now select "Livestock and Poultry Carcass Grading Regulations" and browse through to answer the following

How many grades exist for beef carcasses?
What are the names of these grades, and what are the main criteria that are considered in grading beef carcasses?
Next time you eat a piece of steak, you should have a better understanding of what the "Triple A" means!

Grade standard descriptions for processed fruits and vegetables indicate that the grades are based on aesthetic qualities of the fruits and vegetables. Although there is not a great deal of information available, it appears that Canada Fancy and Canada Standard processed fruits and vegetables are similar in nutrient value. Thus the grades do not necessarily indicate that a better grade (fancy) is superior to a lower grade (standard) from a nutrient point of view.

Eggs are graded only if certain criteria are met, and then only by an inspector at a registered egg station. The eggs are evaluated for weight, cleanliness, soundness and shape of shell, shape and position of yolk in the egg during candling, size of air cell (small = fresh), abnormalities (eg blood spots)

Meat and poultry inspection and grading ensure that only sound, disease-free animals are converted into edible meat cuts and meat products. Grade standards for meat and poultry are based on aesthetic parameters such as fat covering, fat colour, animal maturity and texture of the muscle and fat.

From the nutritional point of view, there do not appear to be marked differences in the nutrient density among the various grades of meat when the lean portion of the meat is considered.

In some cases (e.g., ground beef), additional compositional standards are established. What is the difference between "regular" and "lean" ground beef"? Definitions and standards of identity of meat and meat products are defined within The Food and Drugs Act, which is administered by Health Canada.

Natural Health Products

To deal with the uniqueness of emerging products which are neither strictly foods nor drugs, the government has established a Natural Health Products Directorate, responsible for regulations and labelling guidelines for these products. We will learn about this topic in Lesson 13.

International Regulations

The Codex Alimentarius Commission was established in 1963 by the World Health Organization and the Food and Agriculture Organization of the United Nations to develop international food standards to protect consumer health and to facilitate fair trading practices in foods. Today, there are more than 160 member countries including Canada. Canada's participation in Codex is coordinated through the Office of the Codex Contact Point for Canada, located in the Food Directorate, Health Products and Food Branch of Health Canada.

If you are interested in the regulations in the United States, you may wish to check out the website of the US Food and Drug Administration, Centre for Food Safety and Applied Nutrition:

The Agriculture and Agri-Food Canada website for information concerning US FDA regulations is also useful especially for import-export cases:

In summary, you have gained an insight into the various Acts and regulations that apply to food in Canada. You should have gained an appreciation of how the various regulations operate to ensure that Canadian consumers have access to a safe, high quality food supply.

Food Additives

There is probably no component of the food system that has generated so much discussion among the consuming public as food additives. Many myths and half-truths abound about food additives, their uses and the perceived dangers related to the presence of additives in foods in the Canadian food supply. Compounding this is the prevalence of American radio, television, newspapers and magazines in Canada with articles about the positive and, in the majority of cases, negative aspects about food additives.

As you will note shortly, the Canadian definition of a food additive is not the same as the definition of a food additive in the United States. This has led to much of the confusion in the eyes of the Canadian public, who at times may know more about the United States regulations and legislation than the Canadian regulations and legislation and the Food and Drugs Act of Canada.

Canadian Definition

A food additive is any substance, the use of which results, or may reasonably be expected to result in it or its by-products becoming a part of or affecting the characteristics of a food. Under the Canadian definition, the following are considered NOT to be additives:

  • any nutritive material that is used, recognized or commonly sold as an article or ingredient of food
  • amino acids, mineral nutrients and vitamins
  • spices, seasonings, flavouring preparations, essential oils, oleoresins and natural extractives
  • food packaging materials and components thereof
  • drugs recommended for administration to animals that may be consumed as food.

The exceptions are not included in the definition of a food additive since regulations in other divisions of the food regulations of The Food and Drugs Act of Canada govern their use.

American Definition

Now compare the Canadian definition of a food additive with the definition adhered to in the United States by the Food and Drug Administration, the federal counterpart to the Health Products and Food Branch of Health Canada.

"In its broadest sense, a food additive is any substance added to food. Legally, the term refers to 'any substance the intended use which results or may reasonably be expected to result-directly or indirectly-in its becoming a component or otherwise affecting the characteristics of any food.' This definition includes any substance used in the production, processing, treatment, packaging, transportation or storage of food.

If a substance is added to a food for a specific purpose in that food, it is referred to as a direct additive. For example, the low-calorie sweetener aspartame, which is used in beverages, puddings, yogurt, chewing gum and other foods, is considered a direct additive. Many direct additives are identified on the ingredient label of foods.

Indirect food additives are those that become part of the food in trace amounts due to its packaging, storage or other handling. For instance, minute amounts of packaging substances may find their way into foods during storage. Food packaging manufacturers must prove to the U.S. Food and Drug Administration (FDA) that all materials coming in contact with food are safe, before they are permitted for use in such a manner."

(Quoted from the answer to "What is a food additive?" in the FDA/IFIC Brochure:January 1992 from the U. S. Food and Drug Administration, located at this website:

Although the Canadian and American definitions of food additives sound somewhat similar there are substantial differences between them as illustrated in the following table. You can clearly deduce that confusion can exist among consumers getting their information from the media from two neighbouring countries:

Considered Food Additives Canada USA
Nutritive materials, vitamins, minerals and amino acids No Yes
Spices, seasonings and flavourings No Yes
Agricultural chemical residues a No Yes
Food packaging components a No Yes
Drugs recommended for therapeutic use and as feed additives for administration to food producing animals a No Yes
Number of additives permitted (on the books) ~ 300 > 2600

a These are considered as contaminants in Canada but as unintentional food additives in the United States.

Justified Uses

The Food and Agriculture Organization (FAO) of the United Nations has stated that the use of food additives is justified when one or more of the following conditions are met:

  • additives used to maintain nutritional quality of the food. Use of additives that prevent or inhibit destruction of nutrients during processing and storage (e.g., use of antioxidants to prevent destruction of linoleic acid in oils);
  • additives that function to enhance the keeping quality or stability of the food with a concomitant decrease in food wastage (e.g., use of antioxidants to delay fat oxidation; antimicrobial agents to delay microbial spoilage of food);
  • additives used to make foods attractive without deception (e.g., use of orange/yellow colours in margarine to provide a pleasing appearance; colouring agents are not permitted for use in fresh meats such as ground beef because a colouring agent could disguise the colour changes that signify the onset of spoilage of the meat);
  • additives used to provide essential aids to food processing (e.g., use of emulsifying agents to promote formation of stable emulsions).

Regulations in Canada

Division 16 FOOD ADDITIVES of The Food and Drug Regulations (FDR) for a detailed list of food additives set out in tabular form:
The list provides the following information:

  • The purpose of the food additives are listed (eg. anti-caking agents);
  • The name of the additives that can be used for that purpose;
  • Foods in which they are permitted and the maximum amount permitted.

Since the listing of food additives is a positive list, if a food is not listed in the tables the additive in question cannot legally be used in that food item. An example of a page from Division 16 is shown in Figure 4.2.

What is "Good manufacturing practice"?
When the maximum level of use for a food additive indicates "Good manufacturing practice" (GMP); it basically means the minimum amount of an additive required to accomplish the specific purpose for which the additive is listed. This minimum amount is based on technical food processing needs.

There are 15 categories of food additives in Canada. The categories and examples of the additives are shown in Table 4.3 of this lesson. A full listing of food additives and their functions can be found in the Food Additive Dictionary in the course readings section.

Some additives are listed in more than one category since an additive can have several functions in foods. Ascorbic acid, for example, functions as a dough conditioning agent when used in bread formulations, but it is also listed as a preservative since it also has antioxidant functionality.

The guidelines for the use of food additives in Canada are shown below:

  1. the food additive must be safe for continued use;
  2. the use of the food additive must not lead to deception; and
  3. the use of the food additive results in an advantage to the consumer by improving or maintaining the nutritive value, quantity, quality or acceptability of the food.

These guidelines apply to foods produced in Canada for sale within Canada and also to foods imported from other countries. The guidelines basically state that the food additives must be safe for continuous use, their use must not lead to deception and their use must result in an advantage to the consumer. Even if a food additive is considered to be safe, use of that food additive will not be permitted if it does not create an advantage for the consumer or if it is not clearly established that the food additive performs the function for which its use was intended.

Approval Process

The information that companies must provide when submitting applications to the Health Protection Branch of Health Canada for approval of a new food additive is listed below:

  • Composition, properties, method of manufacture and specifications of the substance to be used as a food additive;
  • Amount and purpose of use;
  • An acceptable method of analysis to determine the presence and concentration of the proposed food additive
  • Data establishing that the proposed food additive will have the intended physical or other technical effect;
  • Detailed reporting of tests conducted to establish the safety of the proposed food additive. Those studies must include: biochemical and physiological tests; subacute and chronic toxicity tests; and reproduction studies
  • A proposed maximum limit for residues of the food additive in or upon the finished food;
  • Specimens of the labelling proposed for the food additive; and
  • A sample of the food additive.

Reference: FDR, Division 16, B.16.002.

Dose Response Curve

Note that the information required relates to both the technological properties of the proposed additive as well as the long term safety of the additive. This type of documentation was required when the G.D. Searle Company applied to have the low caloric sweetener, aspartame, approved for use as a food additive in Canada.

When the Health Products & Food Branch obtained the information they evaluated it relative to the safety of aspartame as well as its technological properties and proposed uses in foods. The use level permitted in specified foods was determined taking the following parameters into consideration:

  • No effect level (no observed adverse effect level) = the highest level of the chemical which caused no harmful effects in the test animals.
  • No effect level for humans = no effect level in animals, divided by a safety factor. For most food additives the safety factor is generally 100.
  • Acceptable daily intake = daily dosage of a chemical which during an entire lifetime appears to be without appreciable risk on the basis of all facts known at that time. The acceptable daily intake is expressed as mg intake per kg body weight.
  • Without appreciable risk = the practical certainty that injury will not result even after a lifetime of exposure.
  • The probable daily intake of a food additive is determined to ensure that this value would not exceed the acceptable daily intake. Food consumption estimates of particular food commodities are used to determine the probable daily intake of the food additive in question. Data from food consumption surveys as well as information from Statistics Canada and the published scientific literature are used to estimate consumption of particular food items by various groups in Canada (e.g., children, teenagers, the elderly, etc.).

If the probable daily intake of the food additive in question were to exceed the acceptable daily intake, the additive would not be approved for use or it would be approved for very restricted use. These parameters will be discussed again in Lesson 12.

Two additives, aspartame and nitrites, will now be described in order to give you some insight into the controversies which surrounded those additives and also into the decision-making processes with regard to risk/benefit issues.


Kroger, M, Meister, K. and Kava, R. 2006. Low-calorie sweeteners and other sugar substitutes: A review of the safety issues. Comprehensive Reviews in Food Science and Food Safety 5: 35-47 (read esp pp. 37-39).

Health Canada, Food Program: Safety of Aspartame (

Case Study: Aspartame

Aspartame is a low-calorie sweetener yielding 4 Cal/g when metabolized. On a weight basis, aspartame yields the same caloric value as an equivalent weight of sucrose. Since aspartame is intensely sweet, it can be used in very small quantities and thus can be added to sweeten "low-calorie" foods (review Lesson 3). Aspartame was approved for use in Canada in 1981. Since its introduction as an approved sweetening agent, aspartame has received much attention in the media with respect to the alleged risks related to the presence of aspartame in foods.

You will note in the article that aspartame is digested in the human body to its constituent components (aspartic acid, phenylalanine and methanol) which are metabolized by normal metabolic routes. The safety aspects of aspartic acid, phenylalanine and methanol are discussed in the article. Aspartame also has not demonstrated carcinogenicity in animal studies. Aspartame in foods can undergo degradation to diketopiperazine (DKP) during long-term storage and when it is exposed to high temperatures for extended periods of time. Studies indicate that DKP does not appear to cause any deleterious effects when ingested.

On the basis of current knowledge of the chemistry of aspartame and on the way in which it is metabolized in the human body, in Canada, aspartame is considered to be safe for consumption at or below the acceptable daily intake (ADI) of 40 mg/kg body weight per day.

What is the ADI for aspartame in the United States?

How Does This Translate to Our Daily Diet?

Let us assume that an individual weighs 60 kg (132 lb). The total acceptable daily intake of aspartame per day for that individual would be:

40 mg aspartame/kg body weight x 60 kg body weight = 2400 mg aspartame/day.

A typical non-caloric soft drink in Canada contains 49 mg aspartame/100 ml soft drink (490 mg/L). The amount of soft drink that person could consume per day that would contribute 2400 mg of aspartame is:

2400 mg aspartame/day and ÷ 490 mg aspartame/ L soft drink = 4.9 L soft drink/day (L = litre)

That is a significant amount of soft drink!

If you consume aspartame sweetened foods you may find it interesting to calculate your daily intake of aspartame. The information you would require is your weight in kilograms, the quantity of each aspartame-containing food consumed daily, as well as the concentration of aspartame in each food item (in mg aspartame/ 100 ml or 100 g, as stated on the list of ingredients for each food item).

Note that most "diet" soft drinks in Canada now contain a blend of aspartame with Acesulfame-K. The risks, to metabolically normal individuals, relating to consumption of aspartame are very small while the benefits relating to use of aspartame are high, particularly for individuals wishing to decrease their caloric intake while still enjoying sweet tasting foods.

The benefits of aspartame to diabetics are obvious. However, there is a small segment of the population for which aspartame in foods poses a substantial risk. Those individuals suffer from phenylketonuria.

Consequently, according to the Canadian labelling regulations, foods to which aspartame is added must:

  1. contain a statement on the label saying "contains phenylalanine" or "has phenylalanine"
  2. list aspartame in the list of ingredients
  3. must also indicate the aspartame content expressed in milligrams per serving of the stated size.

This information is placed on the label of aspartame containing foods to warn phenylketonurics that they should avoid the product or consume it in very limited quantities because of their impaired ability to metabolize phenylalanine. Please read the information on PKU and aspartame in the required reading (Kroger, M, Meister, K. and Kava, R. 2006).

Case Study: Nitrites

The other food additive that we will review is nitrite. The article by Hotchkiss and Cassens provides an overview of the history of the use of nitrites and nitrates in foods and also a history of meat curing and regulation of the curing process

READ: Hotchkiss and Cassens, 1987: "Nitrate, nitrite, and nitroso compounds in foods".

Why Use Nitrites?
Functions of nitrites in cured meats

The reactions of myoglobin, the red pigment in meat, with nitric oxide (formed from nitrites) in cured meats leads to the formation of nitrosohemochrome, the pink colour typical of cured meat products. As shown in Figure on the right, nitrite has several functions in cured meats. By far, the most important role of nitrite is to act as an antimicrobial agent, particularly toward Clostridium botulinum which produces the toxin responsible for botulism.

The fact that the exact mechanism by which nitrites inhibit growth and toxin production by Clostridium botulinum are not fully understood makes the search for an alternative very difficult. To this date an acceptable alternative to nitrite as an antimicrobial agent in cured meats has not been found even though many years and millions of dollars, in numerous countries, have been spent in the search for an alternative for nitrite and also to gain an understanding of the mechanism(s) by which nitrite functions as an anti-botulinal agent.

What Are Some of the Risks Associated with Nitrites?

There is a possibility that nitrites (naturally occurring, or added as an additive, or produced by reduction of nitrates), can react with amines to produce nitrosamines - some of which are potent carcinogens. The discovery in the 1960s of nitrosamines in foods, especially in cured meats, led to many studies and reviews on the risk/benefit situation relating to the use of nitrite and nitrate as food additives, particularly in cured meats. Much research has been conducted on the nitrosation reactions that can occur in foods as well as factors in foods that lead to nitrosamine formation.

Data indicate that foods are not a major source of nitrosamine exposure in humans, and that the greatest exposure comes from use of tobacco products. In foods, beer and fried bacon contribute more nitrosamine to the diet than all other foods combined (see the scientific status summary by Hotchkiss and Cassens). Nevertheless, whenever possible, the exposure to nitrosamines should be minimized.

In 1972, levels of nitrosopyrrolidine in excess of 100 parts per billion (ppb) were detected in fried bacon. [One ppb is an extremely small quantity; if you were to travel one foot on a trip to the Moon, it would represent one part in one billion, since the distance to the Moon is about one billion feet.] By 1982, the level of N-nitrosopyrrolidine in fried bacon produced in the United States was in the range of 10 ppb, about ten-fold lower than the level in 1972. Bacon in the raw stage, has been found to be generally free of nitrosamines which develop during high-heat frying.

You might ask why this dramatic decrease occurred. Research into meat curing operations demonstrated several instances where nitrosation reactions were favoured during the production of cured meats. Changes in the curing process led to decreases in nitrosamine formation. In addition, it was found that compounds such as ascorbic acid, sodium erythorbate (isoascorbate) and alpha-tocopherol (vitamin E) would interfere with the nitrosation reactions. The next time you have an opportunity to read a label on a package of cured meat you will notice that ascorbic acid or sodium erythorbate are listed as one of the ingredients.

Regulatory agencies have been faced with a dilemma as far as nitrite in foods, particularly cured meats, is concerned. It is known that under certain circumstances, particularly during frying of bacon, that nitrosamines can be formed.

  • Some nitrosamines are potent carcinogens while others are non-carcinogenic.
  • The type and quantity of nitrosamines that are formed depend on the reactants and the conditions present in the food.

The article "Nitrates, nitrites, and nitroso compounds in foods" reviews the conditions that favour as well as those that impede nitrosamine formation. It also presents the risk/benefit situation with regard to nitrates (NO3) and nitrites (NO2) in the diet.

Risks and Benefits

What are some important facts in assessing the risks and benefits of allowing nitrates as a food additive in cured meats?

The following information may help to put the issue into a clearer perspective:

  • Our major intake of nitrate is from that naturally found in vegetables (86%), with cured meats contributing only 9% and other food commodities the remaining 5% of the nitrate in food.
  • Nitrite formed from nitrate in the secretions from the salivary glands (in our saliva) represents the greatest intake of nitrite (77%). Cured meats and other food commodities represent 21% and 2 %, respectively of our nitrite intake.
  • Even if nitrite was de-listed as a food additive, we would still be exposed to a substantial intake of nitrite due to its presence in saliva.
  • It has also been shown that nitrosamines are formed in the human stomach even when the diet does not contain any nitrite because of the conversion of salivary nitrate to nitrite by bacteria in our mouths.
  • The pH and temperature of the human stomach are in the optimum range for nitrosation reactions.

Consequently, humans have been exposed to nitrosamines for eons of time.

It is extremely difficult to quantify the risk posed to our health by the use of nitrites as a food additive. The risks appear to be very low.

On the other hand, the risk of botulism from cured meats if nitrites were banned appear to be high, based on information on the incidence of occurrence of Clostridium botulinum spores in raw meats.

The risk/benefit situation related to the use of nitrites in cured meats as follows:

Risks Benefits
If nitrite is used: Potential of increased nitrosamine content in the diet. This does not appear to be a significant risk. Production of cured meat products at reasonable cost with adequate control of Clostridium botulinum
If nitrite is not used: Increased potential for growth and toxin production by Clostridium botulinum in perishable cured meat products under abusive conditions.
Shelf-stable canned cured meat products would probably not be available because the increased heat treatment required would produce a product with an undesirable texture.
Decreased risks due to a decreased load of nitrosamines in the diet. The magnitude of this benefit may not be measurable due to the current load of nitrosamines in the diet from other sources and from nitrosamines formed in vivo.

In Conclusion

Generally, risk/benefit issues are not black and white; often they are shrouded in shades of gray. However, with the information you have gained in this course, you should be able to determine objectively the validity of reports that you may encounter in the media about food additives and about food safety issues.


FNH 200 Course content on this wiki page and associated lesson pages was originally authored by Drs. Brent Skura, Andrea Liceaga, and Eunice Li-Chan. Ongoing edits and updates are contributed by past and current instructors including Drs. Andrea Liceaga, Azita Madadi-Noei, Nooshin Alizadeh-Pasdar, and Judy Chan.

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