The Taiwan authorities have announced recently that several imported oatmeal products for sale in Taiwan were found to have glyphosate ( a pesticide) residue s at levels between 0.1 ppm and 1.8ppm (mg/kg) , violating its zero tolerance policy on glyphosate residue in oatmeal products .
2. Members of the public may have misinterpreted that the non-compliant result of glyphosate in oatmeal as reported had exceeded either their "maximum residue limits", "default values" or "detection limits" stipulated by relevant Taiwan Authority (please refer to para 7-9 of this article). Apart from clarifying these misinterpretations, we would like to point out that the pesticide residues at the detected levels have nothing to do with food safety.
3. According to the Taiwan authorities, Taiwan has set maximum residue limits (MRLs) for glyphosate in certain crops (such as corns and wheat). However, Taiwan does not produce oats and neither the oats-exporting countries nor the trade has made any proposal to the authorities for establishing limits for glyphosate residues in oats. Without the support of relevant scientific data, zero tolerance applies to glyphosate residue in oats under Taiwanese law.
4. The Codex Alimentarius Commission (Codex) jointly set up by the Food and Agriculture Organization and the World Health Organization of the United Nations has established MRLs for pesticide / commodity combinations (i.e. the maximum concentration of specified pesticide residues permitted in specified food commodities, e.g. glyphosate in oats) based on the following principles –
(i) Apply the minimum quantities necessary to achieve adequate pest control;
(ii)The level of residues is unlikely to pose adverse health effect upon normal consumption.
5. The existing Codex MRL for glyphosate in oats is 30 ppm, which is the same standard adopted by Hong Kong. The levels of glyphosate residues detected by the Taiwan authorities in oatmeal samples are well below the Codex limits.
6. In light of Taiwan's announcement, the Centre for Food Safety (CFS) has contacted the Taiwan authorities for more information and has taken follow up actions, including contacting major local importers and conducting sales checks at major local outlets. At the moment, there are no oatmeal products known to be involved in the food incident available in the local market. For the sake of prudence, the CFS has collected 13 oatmeal samples (including Quaker brand products) for the testing of glyphosate, all meet the Codex limits and the statutory standards of Hong Kong (glyphosate residue levels between 0.14 ppm and 1.7ppm).
7. The maximum residue limits (MRLs) / extraneous maximum residue limits (EMRLs) stipulated on each pesticide-food pair by different countries/ areas could be different. Generally speaking, members of the Codex Alimentarius (Codex) would usually adopt the standards established by the organization. If these standards are considered not appropriate, individual member / member organization of Codex may set their own MRLs/ EMRLs on the basis of appropriate data obtained mainly from supervised field trials according to good agricultural practice (GAP). Moreover, certain countries / areas (like EU, Japan and Taiwan) had implemented "default values" or set their MRLs/EMRLs according to the "detection limits" when specific pesticide-food pairs are not available. Default values and detection limits are usually either set at the limits of detection made possible by the laboratory or at a very low levels, both of which have no relevance to the safety profile comprising toxicity and usage of pesticides concerned. Taking chlorpyrifos as an example, 3 out of a total of 81 MRLs (i.e. "others(fruits and vegetables)", "others(cereals grains)" and "others(teas)") are set in accordance to the detection limits.
8. In addition to the use of "default values" and "detection limits" in setting their MRLs, some countries/areas (like Taiwan) also stipulated that the detection of pesticide is not allowed in food that without a designated residual limits. Oatmeal samples that have been detected with glyphosate by the Taiwan Authority recently fits this scenario exactly.
9. As MRLs are generally established on the data obtained mainly from supervised field trials implemented in accordance to good agricultural practice, it is worthwhile to highlight that principle and methodology in deriving at the default values is totally different from that of setting up of the GAP-based MRLs. Therefore, numerical comparison of these figures are meaningless and carries no implications on which approach is more stringent than the other.