Safety evaluation of certain food additives - ipcs inchem

222 SULFITES: ASSESSMENT OF DIETARY EXPOSURE
In its last evaluation of sulfites at the fifty-first meeting, the Committee noted
that potential dietary exposures based on maximum levels (MLs) 1 proposed in the
draft Codex General Standard for Food Additives (GSFA) and on national mean
food consumption data exceeded the ADI in the three Member States that submitted
such data. Six Member States also submitted data in which dietary exposure was
assessed on the basis of MLs in their national regulations and on mean food
consumptions; mean potential dietary exposure of consumers of food containing
sulfites did not exceed the ADI. The potential for high-percentile consumers of foods
containing sulfites to exceed the ADI was shown to exist, but available data were
insufficient to estimate the number of such consumers or the magnitude and
duration of intake greater than the ADI.
A review of all permitted food additives was undertaken as part of the review
of the Australian Food Standards Code (Australia New Zealand Food Authority,
2002; Food Standards Australia New Zealand, 2006). Within this review, sulfites
were identified as a cause for health concern because the estimated dietary
exposures to these preservatives had the potential to exceed the ADI both in
the whole population and in specific population subsets. Consequently, it was
recommended that the concentration of sulfites in food and the dietary exposure to
sulfites should be monitored. Therefore, sulfites were selected for assessment in
the 21st Australian Total Diet Study (Food Standards Australia New Zealand, 2005),
and Australia requested the Codex Committee on Food Additives and Contaminants
(CCFAC, later split into CCFA and the Codex Committee on Contaminants in Food
[CCCF]) at its Thirty-eighth Session (Codex Alimentarius Commission, 2006) to put
a dietary exposure assessment of sulfites on the priority list for evaluation by the
Joint FAO/WHO Expert Committee on Food Additives (JECFA). The Thirty-ninth
Session of CCFA reconfirmed the inclusion of sulfites on the priority list as a high
priority (Codex Alimentarius Commission, 2007a).
As sulfites are known to cause adverse reactions in specific subsets of the
population, there are specific provisions in the Codex General Standard for the
Labelling of Prepackaged Foods (Codex Alimentarius Commission, 1991) and in
national legislation in a number of countries for the labelling of foods and beverages
containing sulfites (e.g. in Directive 2003/89/EC; European Commission, 2003).
This issue and that of the potential acute toxicity of sulfites in general were not dealt
with by the Committee at its present meeting, which focused on long-term dietary
exposure, in line with the CCFA request.
2. CHEMISTRY AND ANALYTICAL METHODS
2.1 Chemistry
The additives listed under sulfites in the current Codex GSFA are sulfur
dioxide (International Numbering System [INS] 220), sodium sulfite (INS 221),
sodium hydrogen sulfite (INS 222), sodium metabisulfite (INS 223), potassium
metabisulfite (INS 224), potassium sulfite (INS 225), calcium hydrogen sulfite
1 Throughout the present report, the term maximum level (ML) is used to represent any
maximum level set for a regulatory purpose at a national or international level.