SAFEGUARDS | Food NO. 177/16

SafeGuardS fresh vegetables in basket

MRLs for Hexythiazox, proposed by the Pest Control Products Act, from Health Canada’s Pest Management Regulatory Agency (PMRA) for foods imported to and sold in Canada have been adopted by the WTO. They entered into force on October 26, 2016.

Hexythiazox (trans-5-(4-chlorophenenyl)-N-cyclohexyl-4-methyl-2-oxothiazolidine-3-caroxamide) is an acaricide that is utilized to control mites on plants. This compound is widely used on crops such as pear, apple, citrus, tree nuts, stone fruits, cranberries, non-bearing trees, vines, strawberries, cotton, hops, mint, ornamental landscape plantings, orchids, and alfalfa. However, it has been concluded that there a risk to human health from dietary exposure.

Food safety is a critical area for consumers; therefore, the presence of Hexythiazox residues in crops is increasingly a concern in many countries. The Codex Alimentarius Commission has tried to develop international MRLs, but these do not cover all food commodities. A lack of MRLs for local foods and the different dietary exposure of consumers in different areas, has led to the main importing countries, such as the EU, USA, Canada, Australia, and Japan to establish their own MRLs. Proposed MRLs for Hexythiazox in Canada were addressed in document PMRL2016-37 [1] and notified to the WTO on July 26, 2016 in accordance with its Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement). Recently, the WTO has adopted these MRLs and apply them to Canadian foods as shown in Table 1. [2]

Table 1: Maximum residue limits for Hexythiazox in various food commodities

Common Name Commodity Parts per million (ppm)
Hexythiazox Citrus oil 24
Hops (dried) 9.0
Low growing berries 6.0
Sorghum 3.0
Dates; dried prune plums; peppermint tops; spearmint tops 2.0
Caneberries 1.5
Small fruits vine climbing, except fuzzy kiwifruit; stone fruits 1.0
Citrus peel 0.9
Citrus fruit; tomatoes 0.5
Pome fruits; dry adzuki beans; dry beans; dry blackeyed peas; dry board beans, dry chickpeas; dry cowpea seeds; dry guar seeds; dry kidney beans, dried lablab beans; dry lima beans; dry moth beans; dry mung beans; dry navy beans; dry pink beans; dry pinto beans, dry rice beans, dry southern peas; dry tepary beans; dry urd beans; grain lupin 0.4

Succulent shelled blackeyed peas;
succulent shelled broad beans;
succulent shelled cowpeas;
succulent shelled lima beans succulent shelled southern peas

Corn oil (refined) 0.06
Sweet corn kernels plus cob with husks removed 0.04
Field corn flour 0.03
Field corn; potatoes; tree nuts including pistachios 0.02

What do the changes mean?

This update has the potential to affect agricultural producers, food manufacturers, and pesticide manufacturers. Food products destined for Canada, if listed in Table 1, must not have Hexythiazox residues exceeding the MRLs listed, all other products (those not listed in Table 1) must not have any Hexythiazox residue on them. Complying with food safety regulations can be a complex, time-consuming and expensive process. Food producers should seek professional advice.

SGS is committed to keeping you informed of regulation news and developments. Leveraging our global network of laboratories and food experts, SGS provides a comprehensive range of food safety and quality solutions, including analytical tests, audits, certifications, inspections, and technical support. We continually invest in our testing, capability, and state-of-the art technology to help you reduce risk, improve food safety and quality. For further more information, please visit our website:

For enquiries, please contact:

Amornpun Dajsiripun
Global Competence Support Centre Food Specialist
t: +66 2683 0541 ext 2423

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