Standard For Pesticide Residue Limits in Edible Mushrooms

Pesticide residues are an important factor affecting the quality and safety of agricultural products. Developing maximum residue limit standards for pesticides is an important technical means for governments in various countries to strengthen pesticide residue risk management, and is also a common practice in various countries around the world. GB 2763-2021 "National Standard for Food Safety - Maximum Residue Limits of Pesticides in Food" is currently a mandatory national standard for maximum residue limits of pesticides in food in China. Its release and implementation are of great significance for China to standardize scientific and rational drug use, strengthen supervision of agricultural product quality and safety, and develop international trade. GB 2763-2021 specifies 10092 residue limits for 564 pesticides in 376 types of food, including more detailed requirements for pesticide residues in edible mushrooms. Appendix A of GB 2763-2021 specifies the food categories and testing sites, and stipulates that edible mushrooms are divided into two categories: mushrooms (shiitake mushrooms, golden needle mushrooms, pleurotus ostreatus, tea tree mushrooms, bamboo fungus, grass mushrooms, morel mushrooms, boletus, mushroom, matsutake, bisporus mushrooms, monkey head mushrooms, white mushroom, apricot mushroom, etc.) and agaric mushrooms (black fungus, white fungus, golden fungus, black fungus, stone fungus, etc.), with the testing sites being whole. In November 2022, GB 2763.1-2022 "National Food Safety Standards - Maximum Residue Limits for 112 Pesticides such as 2,4-dibutyrate Sodium Salt in Food" was released, adding one new limit standard for carbendazim in Agaricus bisporus. This standard was officially implemented on May 11, 2023. At present, there are 69 pesticide residue limits related to edible mushrooms, of which 26 are temporary limits, as shown in Table 2.

Compared with GB2763-2019, GB2763-2021 has added 46 pesticides such as imidacloprid (see Table 2, numbers 24-69). The newly established maximum residue limits for imidacloprid and thiacloprid on agaricus bisporus (fresh) are 2 and 0.5mg/kg, respectively; The maximum residue limit (temporary limit) of sodium dichloroisocyanurate on mushroom (fresh) is 10mg/kg; The maximum residue limits of cypermethrin and high-efficiency cypermethrin were revised from 0.5mg/kg on mushrooms (fresh) to 0.5mg/kg on mushrooms (fresh) and 0.7 mg/kg on agaricus (fresh); The maximum residue limit of dimethoate on edible mushrooms has been reduced from 0.5mg/kg to 0.01mg/kg, and has been adjusted to the official limit. The overall limit value is close to Japan's "positive list system" or the EU's "uniform standard".

GB2763-2021 and GB2763.1-2022 stipulate 35 pesticide residue detection method standards related to edible mushroom pesticide residues, mainly including GB23200.113, NY/T 761, GB23200.8, and GB/T 20769. Among them, GB23200.121, GB23200.116, and SN/T 4591 are new pesticide residue detection method standards, and 19 pesticides do not specify pesticide residue detection methods. The detection of pesticide residues in edible mushrooms can also refer to other relevant national and industry standards, such as GB23200.12-2016, GB 23200.15-2016, and NY/T 1380-2007. There are also relevant regulations in the industry standards for entry and exit inspection and quarantine in China, such as SN/T 0217-2014, SN/T 0491-2019, SN/T 0693-2019, and SN/T 2233-2020. According to literature reports, the detection methods for pesticide residues in edible mushrooms are more complex compared to fruits and vegetables, and improper selection of methods can easily lead to false positive results.

So far, GB 2763 has undergone 5 revisions and 2 additions since its first promulgation in 2005. Among them, the 2005 version of GB2763 did not separately establish limit standards for edible fungi. The 2012 version listed edible fungi as a main agricultural product for the first time and established 17 pesticide maximum residue limits. Currently, the current new version of GB2763 has increased the number of pesticide maximum residue limits for edible fungi to 69; The proportion of pesticide types with maximum residue limits in edible mushrooms in all pesticide types in GB 2763 has increased from around 5% in the 2019 version to over 12%. From this, it can be seen that the types and limited quantities of pesticide residues in edible mushrooms are increasing, and the maximum residue limit standards for pesticides in food in China are constantly improving.