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Date:

September 2, 2000

Subject:

Substantial Equivalence

 

‘Substantial Equivalence’ And The Precautionary Principle: A Challenge To Risk
Assessment
Andrew Apel, editor
AgBiotech Reporter
http://www.bioreporter.com

With the ascendance of the Precautionary Principle, we have seen a concomitant rise
in the number of attacks on the doctrine of substantial equivalence. In this
submission to AgBioView, I argue that this is because the Precautionary Principle
and attacks on the doctrine of substantial equivalence both arise from difficulties
involving an important, yet overlooked facet of the doctrine of substantial
equivalence. Furthermore, I suggest that a fuller articulation of the doctrine of
substantial equivalence could not only improve the current art of risk assessment,
but also provide a foundation for justifiable application of the Precautionary
Principle in certain instances, something the Principle lacks in its current
formulation.

While the existence of a Precautionary Principle is affirmed by many, its
formulations are numerous and as a result, it remains poorly defined. The
politically authoritative version is found in the Biosafety Protocol of the
Convention on Biodiversity, which states in part: “Lack of scientific certainty due
to insufficient relevant scientific information and knowledge regarding the extent
of the potential adverse effects of a living modified organism on the conservation
and sustainable use of biological diversity in the Party of import, taking also
into account risks to human health, shall not prevent that Party from taking a
decision, as appropriate, with regard to the import of that living modified
organism intended for direct use as food or feed, or for processing, in order to
avoid or minimize such potential adverse effects.”

The doctrine of substantial equivalence also claims an independent existence with
numerous formulations. However, it is generally agreed that its best expression is
found in a 1993 document by the OECD4, which was later endorsed in 1996 by the FAO
and WHO. It reads as follows: “For foods and food components from organisms
developed by the application of modern biotechnology, the most practical approach
to the determination is to consider whether they are substantially equivalent to
analogous food product(s) if such exist....The concept of substantial equivalence
embodies the idea that existing organisms used as foods, or as a source of food,
can be used as the basis for comparison when assessing the safety of human
consumption of a food or food component that has been modified or is new.”

The doctrine of substantial equivalence is under fire by many groups and
individuals, and the most prominent criticism of that doctrine appeared in the
October 7, 1999 edition of Nature, in an article titled “Beyond ‘Substantial
Equivalence.’”

In that article, the authors claim that in the context of genetically engineered
organisms, the doctrine amounts to “just wishful thinking.” Since the relationship
between genetics, chemical composition and toxicological risk remains unknown, the
authors argue, the doctrine “is tantamount to pretending to have adequate grounds
to judge whether or not products are safe.” For support of their assertion, the
authors rely in part on a statement by a Dutch government team to the effect that
“compositional analysis...as a screening method for unintended effects...of the
genetic modification has its limitations...in particular regarding unknown
anti-nutrients and natural toxins.” Because of this, the authors demand that the
products of modern biotechnology be subjected to biological, toxicological and
immunological tests.

The Precautionary Principle and the criticism of the doctrine of substantial
equivalence both have a salient feature in common: both rely critically on treating
a lack of evidence as evidence which either justifies or requires a particular
course of action. Indeed, that lack of evidence is a precondition for both the
application of the Precautionary Principle and for the testing demanded by critics
of the doctrine of substantial equivalence. “Lack of scientific certainty”
regarding “potential adverse effects” is what allows a party to the Biosafety
Protocol to take action; and according to the critics of the doctrine of
substantial equivalence, action is necessary when “risk remains unknown.”

Since both the advocates of the Precautionary Principle and the critics of
substantial equivalence use a lack of evidence as an approach to responding to
(albeit unknown) risk, both represent species - apparently the same species - of an
approach to risk assessment.

Historically, risk assessment has been regarded as a fact-based evaluation of the
likelihood of certain adverse outcomes which may result from a course of conduct.
As a fact-based evaluation carried out under conditions representing less than
omniscience, risk assessment has relied critically not on the absence of evidence,
but on the evidence available.

The current art requires that risks be assessed objectively, with the use of the
best facts available. Abject reliance on what has never been observed, on the other
hand, courts the accusation of absolute subjectivity. Such a risk assessment cannot
be called subjective in an absolute sense, since one observable fact is required,
though only one: the fact that some things are unknown.

That the current art of risk assessment relies on facts does not mean that it is
free of subjectivity. For instance, ‘acceptable daily intakes’ (ADIs) of substances
deemed worthy of question are usually defined as one-hundredth of the highest dose
shown to be harmless for laboratory animals. The determination of what to question
can be subjective; and the proportion of one-hundredth, while it may be intuitively
satisfying, has not been objectively shown to be based on, e.g., some natural law
conveniently relating toxins to the decimal system.

A still more obvious, yet overlooked subjective feature of the current art of risk
assessment is that it serves a blatantly subjective purpose, by attempting to
answer two questions: What should we be afraid of, and how afraid should we be?

So clearly, the current art of risk assessment cannot be differentiated from the
Precautionary Principle or the claims of the critics of substantial equivalence on
the basis of subjectivity alone. The problem runs much deeper than that.

The doctrine of substantial equivalence accepts the notion that it is possible to
‘know enough’ about something to justify making use of it. The Precautionary
Principle enables rejection of this notion, while the critics of substantial
equivalence appear to reject it outright.

In the current state of the art, it is a commonplace truth that, as critics of
substantial equivalence point out, the relationship between genetics, chemical
composition and toxicological risk remains largely unknown. This happens to be
true, however, of both conventional and genetically modified crops. If the
Precautionary Principle were rigorously applied, or the demands of the critics of
substantial equivalence rigorously adhered to, the incompleteness of the science of
genetics would require both conventional and genetically modified crops to be
treated with an equal degree of heightened scrutiny, or worse. This would be both
drastic and unnecessary. Indeed, such a process could easily remove a number of
popular foods from the human diet because conventional food crops naturally produce
a variety of toxins and carcinogens which in large doses are capable of causing
rodents to suffer.

The doctrine of substantial equivalence gets around the problem of requiring
exhaustive tests of all crops for unknown toxins and carcinogens by accepting that
enough is known about the safety of conventional crops to make it reasonable to eat
them, a notion which the critics of substantial equivalence are constrained, by
practical considerations, to accept. The doctrine goes one step further, by
accepting that confidence in conventional crops is high enough to make them a
“benchmark” for investigating what is novel.

It is precisely at the point of novelty where the advocates of the Precautionary
Principle and the critics of substantial equivalence depart from the current art of
risk assessment. A classical approach would be to assess the relative degree of
risk introduced by the novel trait, based on what is known, and to accept at some
point that enough (though less than everything) is known about the novel trait to
make a determination.

The advocates of the Precautionary Principle assign a prerogative to the lack of
complete information on what is novel. The critics of the doctrine of substantial
equivalence assign an imperative to the lack of complete information on what is
novel. In this way, both groups assess the risks of the incompletely-known status
quo and the risks of the new in radically different ways, to the point where it
becomes impossible to interpret what is new in terms of what is not.

It is also at the point of novelty where the advocates of the Precautionary
Principle and the critics of substantial equivalence appear to employ strictly
subjective methods of risk assessment. That they actually become completely
subjective at this point is not a necessary conclusion, however.

It is nonetheless the most likely conclusion, and it may well be completely valid
in some cases. It is likely that these groups assess the risks of the status quo
and the risks of the new in radically different ways because, in actuality, some
things are so radically new that they cannot be interpreted in terms of the status
quo.

For some, the cell phone is “substantially equivalent” to the telephone, with the
added traits of portability and radio technology. Others find the novelty so great
that concern overwhelms understanding. The same is true in the case of modified
crops, which some see as substantially equivalent but others see as a threat to
their entire world view.

This indicates that there is an unexplored challenge to the art of risk assessment.
It appears that the doctrine of substantial equivalence is not merely an evaluative
tool for regulators, but also central to interpreting the risks of the new in terms
of the familiar risks of the status quo. Doubtless further investigation of the
full scope of the doctrine would better establish the degree to which novelty may
be considered to be sufficiently related to current art to be substantially
equivalent.

Furthermore, such an investigation could help determine what constitutes novelty of
a degree which truly merits an application of the Precautionary Principle, a
feature the Principle sorely lacks in its current formulations. Doubtless such
extreme novelty would require the incorporation of a risk-benefit analysis, which I
have purposely made no effort to address here.