Chemical and Microbiological Contaminants
in
Supplements
1. Background
Since the late 1990s there has been an increasing focus on chemical contaminants in
foods and supplements. This focus is now world-wide as reflected by the increasingly
complex agenda being covered by the Codex Alimentarius Committee on Food
Additives and Contaminants (CCFAC).
Within the European Union (EU) chemical contamination has become the premier
cause of supplement product withdrawal and recall from the market, resulting in
considerable financial losses for the companies involved. In the context of legislation
on chemical contaminants, the EU is not alone and many other countries are following
suit.
It is due to this increasingly complex regulatory environment and the impact of
withdrawals on companies’ finances and reputations that IADSA initiated the
International Working Group on Contaminants in 2004. The Working Group has been
meeting and corresponding over the past two years and has developed Templates of
Chemical Contaminants and suggested maximum levels. For completeness
microbiological specifications have also been added.
At all stages of its discussions and decisions the Working Group concentrated on
its primary objective of helping to facilitate free trade in supplements across national
borders by reducing the possibilities of rejection of product due to contamination.
2. Chemical Contaminants
Chemical contamination can be either from environmental sources (heavy metals,
dioxins, polycyclic aromatic hydrocarbons etc.) or from microbiological action
(mycotoxins). A small number, such as acrylamide and 3-MCPD, can be formed by
chemical reactions during the processing of a food. Fortunately, none of the last
category have been associated with supplements. The chemical contaminants
currently affecting supplements and which appear in the legislation of at least one
major economic area of the world are:
i).
Heavy Metals
The presence of heavy metals (lead, arsenic, mercury etc.) in supplement
ingredients has been a problem for a number of decades.
Existing legislation covers arsenic, cadmium, lead, mercury and total
heavy metals. These have been included in the templates where relevant
to the group of ingredients.
ii).
Dioxins, Furans and Dioxin-like Polychlorinated Biphenyls
These are organic compounds which are found in the environment.
Dioxins and furans can be formed by combustion under certain
conditions and polychlorinated biphenyls (PCBs) are man-made
substances that have been allowed to pollute soil and water courses.
These related groups of substances can be found in the soil, rivers, lakes
and the sea. They can be taken in by both animals and plants in the
course of feeding in the case of land animals and fish and by the normal
metabolic processes in plants.
A number of substances in these groups have been defined as being
carcinogenic or genotoxic as well as having other toxic effects.
Legislative controls apply in a number of countries.
The World Health Organisation (WHO) has assessed the relative toxicity
of a number of dioxins and PCBs and applied a weighting factor to each.
When estimating the toxicity potential of the mixtures of these
substances found as pollutants, the empirical weight of each as measured
by chemical assay is multiplied by the factor assigned by the WHO. The
sum of the adjusted values, known as the Toxic Equivalent or TEQ is
used for control purposes. Thus, the legislation is given as nanograms or
picograms WHO TEQ.
iii). Polycyclic Aromatic Hydrocarbons (PAHs)
PAHs are a large group of closely related organic compounds, many of
which are known carcinogens. They can be formed during a number of
combustion processes and can be found in vehicle fumes and cigarette
smoke. They are present in the atmosphere and can be found in soils and
water courses, thereby affecting both plants and animals where they can
be found in fats and oils. High levels of PAHs have been found in plant
oils and certain botanicals.
Legal controls on levels of PAHs in foods and supplements have been
imposed by a number of countries.
iv). Mycotoxins
Mycotoxins are toxic substances produced as metabolites by certain
species of fungi (moulds) whilst growing on biological substrates. They
are commonly found in plant material when grown and / or harvested
under certain environmental conditions, particularly in warm, moist
atmospheres.
A large number of mycotoxins are known but only a few are currently
under regulatory control (Aflatoxins, Ochratoxin A, Patulin etc.).
v).
Pesticides
The term ‘Pesticide’ covers a very large group of, mainly man-made,
agricultural chemicals, used chiefly to eliminate insects and other pests
affecting crops.
The usage and residue levels of pesticides are controlled in most
countries of the world but there is still a lack of harmonisation. As a
result there are significant differences in legislative requirements, for
example between the USA and the EU.
It is therefore important that compliance with pesticide and residue
levels is at intended point of sale.
vi). Microbiological Contamination
As previously mentioned microbiological contamination, although not
chemical contamination in the accepted sense, has been added to the
templates for completeness.
In terms of the criteria selected the Total Plate Count and Mould / Yeasts
tests give an indication of general quality and have been realistically and
scientifically assessed.
The other tests relate to the detection of potential pathogens, and are
consistent with requirements for most food products.
vii). Radioactivity
Radioactivity in foods and ingredients came under legislative control
following the Chernobyl Nuclear Power Station disaster and the large
amount of radioactive fall-out that resulted.
The botanicals grown in some Eastern European countries are still being
monitored for radioactivity.
viii). Residual Solvents
This criterion relates to extraction solvent residues remaining in
botanical extracts. It should be noted that the lists of permitted solvents
and their residue levels vary considerably between countries and
compliance needs to be with legislation at the point of sale.
xi). Ethylene Oxide
This relates to botanicals. Ethylene oxide was used as a gaseous sterilant
for botanicals. Its use has been prohibited in most countries since the
beginning of the 1990s due to safety concerns with its residue in foods.
xii). Quality Parameters
It was decided to include in the templates covering both plant and
animal oils two oil quality indicators.
3. Use of the Templates
The Contaminant Templates are intended as guides to best practice when developing
or agreeing raw material specifications. They are not intended to be prescriptive or
obligatory. They do not constitute legal documents or imply legal obligations.
The original objective that led to the development of the Templates was to help
facilitate the free trade of supplements across national borders by reducing the
rejection of products due to contamination.
IADSA therefore recommends that the Templates be used as the basis of discussions
between supplier and customer when agreeing raw material specifications. It is
particularly important that they are given serious consideration where the supplement
products are destined for markets outside the country of manufacture.
All the contaminants listed in the Templates are already in Codex Alimentarius
Standards and / or in the legislation of a major economic area. However, it is essential
that companies check the applicable legislation in the countries of intended sale of the
products.
IADSA
13th April 2006