In North America, food labels are based on the content of the food. This is known as a product-based labelling system. But now people are calling for food labels to be based on how the food crop was generated in the first place, whether or not it was genetically modified. This would be extremely problematic.

Presently all food labels must show nutritional information like protein, carbohydrate and fat content. A good thing, as consumers are becoming more nutrition conscious.

All known strong allergenic content must also be on the label. This is a safety issue as some people can have severe problems when they consume particular allergenic proteins.

These are the two reasons why certain information must be on food labels. This product-based system of labelling is objective, verifiable and enforceable. Truth in labelling is very important.

All food products of biotechnology (GM food) are examined extensively right down to the amino acid (building blocks of proteins), carbohydrate, fat, vitamin, micronutrient and macronutrient content long before the product reaches the market. If the biotechnology product is the same as the parental variety then the product is said to be substantially equivalent. Substantial equivalence is a safety evaluation process endorsed by most scientific bodies around the world including the American Medical Association and the World Health Organization.

Since the biotechnology products are nutritionally the same as their parental varieties, why should a special label be required?

Proteins are made of long chains of 20 different amino acids. Most allergens are proteins and as such have a particular amino acid sequences that gives them their allergenic properties. At present there are about 500 amino acid sequences of known allergenic proteins in databanks around the world. This represents the vast majority of known allergenic proteins. All biotechnology-engineered proteins are compared with the known allergen data banks before they reach the market. If a particular engineered protein has sequence similarities with a known allergenic protein then there are many more requirements that must be met before that particular GM food product is given approval for commercialization. There are no GM food products available today that match anything in the allergen data banks.

This extensive evaluation process for allergenic potential is done on all GM food products long before they reach the market. Is the process perfect? No. But it is certainly far superior to all other types of food, which are not evaluated for allergens at all.

As technology advances we will be better able to further refine the evaluation process. But clearly neither the nutritional content nor the potential allergen content regulations are violated by the lack of GM specific labelling.

For the sake of argument, let's say we are going to label food based on the process used to make it and not the product itself. Here are a few of the hurdles that must be addressed.

First, what is GM food? Different countries have different definitions. Is anything that has its DNA manipulated a GM product? If this is the basis for defining a GM food then virtually every food on the market including organic food is a GM food.

Other modern plant breeding techniques cause random mutations throughout the entire DNA of the plant in order to make new varieties. There is no evaluation of these types of genetic mutations. Only GM crops are extensively analysed at the genetic level.

Second, do we consider highly processed foods genetically modified? For example, is canola oil, which contains virtually no DNA or protein, a GM food? With no detectable DNA or protein it would become impossible to verify labels. This means enforcement would also be impossible.

And third, what do we do about the detection of GM food products? The average biotechnology crop has the engineered protein accounting for 0.00004 per cent of the total protein of the plant. If anything over 0.9 per cent GM content must be labelled (EU regulations) then that would mean labelling for GM content that is 0.0000004 per cent.

Such low levels are far below the levels of other common contaminants of grain such as insect parts and rodent hair. There are very few systems in place that have that level of sensitivity and accuracy.

What should happen with these foods, as labels would not be verifiable and therefore would become unenforceable? These types of problems have been seen in parts of the world that have adopted GM specific labelling systems.

Here is an example of the difficulties of moving to a process-based labelling system. Consider a typical loaf of whole wheat bread. The wheat may or may not be GM depending on the variety (triticale is by most definitions a product of genetic manipulation). The yeast is probably GM. If the fat is from canola it is probably GM but has no detectable DNA or protein in it. Because of the low levels of detectable GM ingredients it is impossible to truthfully label this product as GM or non-GM. Since it is imperative that all labels be truthful, what do we do with a loaf of bread?

It has been said that consumers should have the right to choose, and only labelling GM food will give them that choice. This is a false argument.

About 70 per cent of foods in the supermarket contain at least one ingredient that is a product of food biotechnology. The exception is organic food. Organic food does not use GM food products. This means that everyone has the choice to avoid GM food. They can simply buy organic food.

New regulations now permit a "GM-free" label. If a company wants to market a product that does not contain GM ingredients then that company can label its food GM-Free. However, that company must pay for the tests to prove their claim. In this way there is more choice for the consumer and the price burden of GM specific labelling is put on those who are demanding the labelling in the first place.

It has been estimated that a GM-specific labelling system would increase food prices about 10 per cent. Since there is absolutely no evidence of any harm coming to anyone from consuming food biotechnology products there should not be a financial penalty put on the average consumer for the (scientifically unjustifiable) labelling demands of the few.

Remember that not one single illness anywhere in the world has been attributed to the consumption of food biotechnology products. All claims to the contrary have been disproved. Considering over two trillion meals with biotechnology products have been consumed, the safety record speaks for itself.

Dramatically changing our product-based food labelling regulations from an objective, verifiable and enforceable system to a subjective, non-verifiable and unenforceable process-based system is not in the public's interest.